U.S. patent application number 15/153630 was filed with the patent office on 2016-09-08 for methods for implanting intraocular shunts.
The applicant listed for this patent is AqueSys, Inc.. Invention is credited to Guenther GRABNER, Christopher HORVATH, Herbert A. REITSAMER, Laszlo O. ROMODA.
Application Number | 20160256317 15/153630 |
Document ID | / |
Family ID | 56851814 |
Filed Date | 2016-09-08 |
United States Patent
Application |
20160256317 |
Kind Code |
A1 |
HORVATH; Christopher ; et
al. |
September 8, 2016 |
METHODS FOR IMPLANTING INTRAOCULAR SHUNTS
Abstract
Glaucoma can be treated by implanting an intraocular shunt into
the eye. Such procedures can employ various deployment devices,
shunts, and implantation techniques. A method for treating glaucoma
can include positioning an intraocular shunt in eye tissue, without
use of an optical apparatus that contacts the eye, such that the
shunt conducts fluid from the anterior chamber of the eye and
delivers a pharmaceutical or biological agent to the eye.
Inventors: |
HORVATH; Christopher;
(Mission Viejo, CA) ; ROMODA; Laszlo O.; (San
Clemente, CA) ; GRABNER; Guenther; (Salzburg, AT)
; REITSAMER; Herbert A.; (Salzburg, AT) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
AqueSys, Inc. |
Aliso Viejo |
CA |
US |
|
|
Family ID: |
56851814 |
Appl. No.: |
15/153630 |
Filed: |
May 12, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14313970 |
Jun 24, 2014 |
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15153630 |
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12946572 |
Nov 15, 2010 |
8852256 |
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14313970 |
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12946222 |
Nov 15, 2010 |
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12946572 |
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12946240 |
Nov 15, 2010 |
8828070 |
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12946222 |
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12946251 |
Nov 15, 2010 |
9095411 |
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12946240 |
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12946263 |
Nov 15, 2010 |
8801766 |
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12946251 |
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13314927 |
Dec 8, 2011 |
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12946263 |
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12946351 |
Nov 15, 2010 |
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13314927 |
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12946556 |
Nov 15, 2010 |
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14313970 |
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14263957 |
Apr 28, 2014 |
9283116 |
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12946556 |
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12946645 |
Nov 15, 2010 |
8721702 |
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14263957 |
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14191340 |
Feb 26, 2014 |
9192516 |
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14313970 |
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12946653 |
Nov 15, 2010 |
8663303 |
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14191340 |
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12946565 |
Nov 15, 2010 |
8974511 |
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14313970 |
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13336758 |
Dec 23, 2011 |
8852137 |
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12946565 |
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12946351 |
Nov 15, 2010 |
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13336758 |
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12946222 |
Nov 15, 2010 |
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12946351 |
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13336803 |
Dec 23, 2011 |
8758290 |
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14313970 |
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12946351 |
Nov 15, 2010 |
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13336803 |
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12946222 |
Nov 15, 2010 |
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12946351 |
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13895170 |
May 15, 2013 |
9326891 |
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14313970 |
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PCT/US2011/060820 |
Nov 15, 2011 |
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13895170 |
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13952543 |
Jul 26, 2013 |
9017276 |
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14313970 |
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12946542 |
Nov 15, 2010 |
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13952543 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61F 9/0017 20130101;
A61B 17/3468 20130101; A61F 9/0008 20130101; A61B 17/3415 20130101;
A61F 9/007 20130101; A61B 17/3417 20130101; A61M 27/002 20130101;
A61F 9/00781 20130101 |
International
Class: |
A61F 9/007 20060101
A61F009/007; A61B 17/34 20060101 A61B017/34 |
Claims
1. A method for deploying a shunt within an eye, the method
comprising: inserting into an eye a deployment device configured to
hold an intraocular shunt, the shunt comprising a pharmaceutical or
biological agent deliverable to the eye; determining, without use
of an optical apparatus that contacts the eye, that a distal
portion of the device is positioned at a position at an anterior
chamber of the eye; and advancing, from the device at the position,
the shunt into eye tissue.
2. The method of claim 1, wherein advancing comprises advancing the
device until a resistance is encountered.
3. The method of claim 1, wherein the eye comprises a cornea, and
wherein the inserting comprises inserting a hollow shaft of the
deployment device into the eye through the cornea.
4. The method of claim 1, wherein the pharmaceutical or biological
agent comprises a coating on a surface of the shunt.
5. The method of claim 4, wherein the pharmaceutical or biological
agent comprises a coating on an exterior surface of the shunt.
6. The method of claim 4, wherein the pharmaceutical or biological
agent comprises a coating on an interior surface of the shunt.
7. The method of claim 1, wherein a portion of the shunt is
impregnated with the pharmaceutical or biological agent.
8. The method of claim 1, wherein the pharmaceutical or biological
agent comprises a time-release pharmaceutical or biological
agent.
9. A method for deploying a shunt within an eye, the method
comprising: inserting into an eye a deployment device configured to
hold an intraocular shunt, the shunt comprising a pharmaceutical or
biological agent deliverable to the eye; advancing the device until
a protrusion on a distal end of a housing of the device contacts an
anatomical feature at an anterior chamber angle of the eye, thereby
providing resistance against further advancement of the device; and
advancing the shunt from the device.
10. The method of claim 9, wherein a distal portion of the housing
comprises a sleeve and a hollow shaft that is movable within the
sleeve, the method further comprising distally advancing the hollow
shaft relative to the sleeve after the advancing the device until
the protrusion contacts the anatomical feature.
11. The method of claim 10, wherein the protrusion is formed
integrally with a distal end of the sleeve.
12. The method of claim 10, wherein the protrusion is connected to
a distal end of the sleeve.
13. The method of claim 10, wherein the pharmaceutical or
biological agent comprises a coating on a surface of the shunt.
14. The method of claim 13, wherein the pharmaceutical or
biological agent comprises a coating on an exterior surface of the
shunt.
15. The method of claim 13, wherein the pharmaceutical or
biological agent comprises a coating on an interior surface of the
shunt.
16. The method of claim 10, wherein a portion of the shunt is
impregnated with the pharmaceutical or biological agent.
17. The method of claim 10, wherein the pharmaceutical or
biological agent comprises a time-release pharmaceutical or
biological agent.
18. A method, for treating an eye, comprising positioning an
intraocular shunt in eye tissue, without use of an optical
apparatus that contacts the eye, such that the shunt conducts fluid
from an anterior chamber of the eye and delivers a pharmaceutical
or biological agent to the eye.
19. The method of claim 18, wherein the positioning comprises
inserting a deployment device, configured to hold the intraocular
shunt, into the eye, and thereafter advancing the deployment device
into the eye until an increased resistance against further
advancement is encountered.
20. The method of claim 18, wherein the eye comprises a cornea, and
wherein the positioning comprises inserting the shunt into the eye
through the cornea.
21. The method of claim 18, wherein the pharmaceutical or
biological agent comprises a coating on a surface of the shunt.
22. The method of claim 21, wherein the pharmaceutical or
biological agent comprises a coating on an exterior surface of the
shunt.
23. The method of claim 21, wherein the pharmaceutical or
biological agent comprises a coating on an interior surface of the
shunt.
24. The method of claim 18, wherein a portion of the shunt is
impregnated with the pharmaceutical or biological agent.
25. The method of claim 18, wherein the pharmaceutical or
biological agent comprises a time-release pharmaceutical or
biological agent.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 14/313,970, filed Jun. 24, 2014; U.S. patent
application Ser. No. 14/313,970 is a continuation-in-part of U.S.
patent application Ser. No. 12/946,572, filed on Nov. 15, 2010, now
U.S. Pat. No. 8,852,256; U.S. patent application Ser. No.
14/313,970 is also a continuation-in-part of U.S. patent
application Ser. No. 12/946,222, filed on Nov. 15, 2010, now
abandoned; U.S. patent application Ser. No. 14/313,970 is also a
continuation-in-part of U.S. patent application Ser. No.
12/946,240, filed on Nov. 15, 2010, now U.S. Pat. No. 8,828,070;
U.S. patent application Ser. No. 14/313,970 is also a
continuation-in-part of U.S. patent application Ser. No.
12/946,251, filed on Nov. 15, 2010, now U.S. Pat. No. 9,095,411;
U.S. patent application Ser. No. 14/313,970 is also a
continuation-in-part of U.S. patent application Ser. No.
12/946,263, filed on Nov. 15, 2010, now U.S. Pat. No. 8,801,766;
U.S. patent application Ser. No. 14/313,970 is also a
continuation-in-part of U.S. patent application Ser. No.
13/314,927, filed Dec. 8, 2011, now abandoned, which is a
continuation-in-part of U.S. patent application Ser. No.
12/946,351, filed on Nov. 15, 2010, now abandoned; U.S. patent
application Ser. No. 14/313,970 is also a continuation-in-part of
U.S. patent application Ser. No. 12/946,556, filed on Nov. 15,
2010, now abandoned; U.S. patent application Ser. No. 14/313,970 is
also a continuation-in-part of U.S. patent application Ser. No.
14/263,957, filed on Apr. 28, 2014, now U.S. Pat. No. 9,283,116,
which is a continuation of U.S. patent application Ser. No.
12/946,645, filed on Nov. 15, 2010, now U.S. Pat. No. 8,721,702;
U.S. patent application Ser. No. 14/313,970 is also a
continuation-in-part of U.S. patent application Ser. No.
14/191,340, filed on Feb. 26, 2014, now U.S. Pat. No. 9,192,516,
which is a continuation of U.S. patent application Ser. No.
12/946,653, filed on Nov. 15, 2010, now U.S. Pat. No. 8,663,303;
U.S. patent application Ser. No. 14/313,970 is also a
continuation-in-part of U.S. patent application Ser. No.
12/946,565, filed on Nov. 15, 2010, now U.S. Pat. No. 8,974,511;
U.S. patent application Ser. No. 14/313,970 is also a
continuation-in-part of U.S. patent application Ser. No.
13/336,758, filed on Dec. 23, 2011, now U.S. Pat. No. 8,852,137,
which is a continuation-in-part of U.S. patent application Ser. No.
12/946,351, filed on Nov. 15, 2010, now abandoned, and which is a
continuation-in-part of U.S. patent application Ser. No.
12/946,222, filed on Nov. 15, 2010, now abandoned; U.S. patent
application Ser. No. 14/313,970 is also a continuation-in-part of
U.S. patent application Ser. No. 13/336,803, filed on Dec. 23,
2011, now U.S. Pat. No. 8,758,290, which is a continuation-in-part
of U.S. patent application Ser. No. 12/946,351, filed on Nov. 15,
2010, now abandoned, and which is a continuation-in-part of U.S.
patent application Ser. No. 12/946,222, filed on Nov. 15, 2010, now
abandoned; U.S. patent application Ser. No. 14/313,970 is also a
continuation-in-part of U.S. patent application Ser. No.
13/895,170, filed on May 15, 2013, which is a continuation of
International Pat. App. No. PCT/US2011/060820, filed on Nov. 15,
2011, which claims the benefit of and priority to U.S. patent
application Ser. No. 12/946,210, filed on Nov. 15, 2010, now U.S.
Pat. No. 8,308,701; and U.S. patent application Ser. No. 14/313,970
is also a continuation-in-part of U.S. patent application Ser. No.
13/952,543, filed on Jul. 26, 2013, now U.S. Pat. No. 9,017,276,
which is a continuation of U.S. patent application Ser. No.
12/946,542, filed on Nov. 15, 2010, now abandoned; the entireties
of each of these applications and patents are incorporated herein
by reference.
BACKGROUND
[0002] 1. Field of the Inventions
[0003] The present inventions generally relate to surgical methods,
implantation devices, and shunts that can be used to treat
glaucoma.
[0004] 2. Description of the Related Art
[0005] Glaucoma is a disease of the eye that affects millions of
people. Glaucoma is associated with an increase in intraocular
pressure resulting either from a failure of a drainage system of an
eye to adequately remove aqueous humor from an anterior chamber of
the eye or overproduction of aqueous humor by a ciliary body in the
eye. Build-up of aqueous humor and resulting intraocular pressure
may result in irreversible damage to the optic nerve and the
retina, which may lead to irreversible retinal damage and
blindness. Glaucoma affects 1 in 200 people aged fifty and younger,
and 1 in 10 over the age of eighty for a total of approximately 70
million people worldwide, and glaucoma is the second leading cause
of blindness in the world.
[0006] There are two main types of glaucoma, "open angle" and
"closed angle" glaucoma. Open angle glaucoma refers to glaucoma
cases in which intraocular pressure increases but an anterior
chamber angle (drainage angle) of an eye remains open. A common
cause of open angle glaucoma is blockage in the trabecular
meshwork, the fluid flow pathways that normally drain aqueous humor
from the anterior chamber of the eye. Closed angle glaucoma refers
to glaucoma cases in which intraocular pressure increases due to
partial or complete closure of the anterior chamber angle. In
closed angle glaucoma, swelling or movement of the iris closes the
anterior chamber angle and blocks fluid from accessing to the
trabecular meshwork, which in turn obstructs outflow of the aqueous
humor from the eye.
[0007] Generally, glaucoma may be treated by surgical intervention
that involves placing a shunt in the eye to result in production of
fluid flow pathways between the anterior chamber and various
structures of the eye involved in aqueous humor drainage (e.g.,
Schlemm's canal, the sclera, or the subconjunctival space). Such
fluid flow pathways allow for aqueous humor to exit the anterior
chamber. Generally, the surgical intervention to implant the shunt
involves inserting into the eye a delivery device that holds an
intraocular shunt, and deploying the shunt within the eye.
[0008] A delivery device holding the shunt enters the eye through a
cornea (ab interno approach), and is advanced across the anterior
chamber. The delivery device is advanced through the sclera until a
distal portion of the device is in proximity to a drainage
structure of the eye. The shunt is then deployed from the delivery
device, producing a conduit between the anterior chamber and
various structures of the eye involved in aqueous humor drainage
(e.g., Schlemm's canal, the sclera, or the subconjunctival space).
See for example, Yu et al. (U.S. Pat. No. 6,544,249 and U.S. Pat.
Pub. No. 2008/0108933) and Prywes (U.S. Pat. No. 6,007,511). Such
fluid flow pathways allow for aqueous humor to exit the anterior
chamber, thereby reducing IOP.
[0009] Such a surgical procedure requires an optical apparatus,
such as a goniolens, so that a surgeon may visualize the delivery
device within the eye and ensure proper placement of the shunt
after it has been deployed from the delivery device.
[0010] Further, various manual and automated deployment devices for
implanting an intraocular shunt have been described. See, for
example, U.S. Pat. No. 6,544,249 and U.S. Pat. Pub. No.
2008/0108933. Most deployment devices are coupled to a hollow
needle which holds the intraocular shunt. Whether an ab externo
approach or an ab interno approach is used, the needle is inserted
into the eye to deploy the intraocular shunt into the eye. The
needle is then withdrawn from the eye.
SUMMARY
[0011] A problem with treating closed angle glaucoma with surgical
intervention is that the closed anterior chamber angle prevents an
operator from advancing the deployment device into the anterior
chamber angle, and thus the device cannot be properly positioned to
deploy an intraocular shunt.
[0012] The present inventions generally relate, among other things,
to methods for treating closed angle glaucoma that involve using a
deployment device that is configured to both re-open a partially or
completely closed anterior chamber angle and deploy an intraocular
shunt. By re-opening the anterior chamber angle, the deployment
device is provided access to the anterior chamber angle so that an
operator may properly position the device to deploy the intraocular
shunt, thereby generating a fluid flow pathway for outflow of
aqueous humor from an anterior chamber of an eye.
[0013] In certain aspects, some methods involve inserting into an
eye a deployment device configured to hold an intraocular shunt,
using the device to re-open an at least partially closed anterior
chamber angle of an eye, and deploying the shunt from the device.
Deploying the shunt results in a flow path from an anterior chamber
of the eye to an area of lower pressure. Exemplary areas of lower
pressure include intra-Tenon's space, the subconjunctival space,
the episcleral vein, the subarachnoid space, the suprachoroidal
space, Schlemm's canal, or drainage structures associated with the
intra-scleral space.
[0014] In other aspects, some methods involve inserting into an eye
a deployment device configured to hold an intraocular shunt,
advancing the device such that a protrusion on a distal end of the
device advances into an at least partially closed anterior chamber
angle of the eye, thereby re-opening the closed angle, and
deploying the shunt from the device. In certain embodiments, a
distal portion of the device includes a sleeve and a hollow shaft
that is movable within the sleeve.
[0015] The present inventions generally provide improved shunts
that facilitate drainage of fluid from an organ. Particularly, some
embodiments of the shunt address and solve the problems with
intraocular shunts.
[0016] The present inventions also generally relate to devices for
deploying intraocular shunts from a delivery device without use of
an optical apparatus that contacts the eye, preferably without use
of any optical apparatus. Some devices accomplish shunt deployment
without use of an optical apparatus by having a biased distal
portion, such that upon entry of the distal portion of the device
into an anterior chamber of an eye, the distal portion slides to
fit within the anterior chamber angle of the eye. A resistance
feedback feature of the device informs an operator that the
deployment device is properly positioned within the anterior
chamber angle of the eye for deployment and proper placement of the
shunt within the eye.
[0017] In particular embodiments, some methods involve inserting
into an eye a deployment device configured to hold an intraocular
shunt, determining that a distal portion of the device is properly
positioned within the eye without use of an optical apparatus that
contacts the eye, and deploying the shunt from the device. In
certain embodiments, determining involves advancing the device
until a resistance is encountered. The resistance indicates to an
operator that a distal end of the device has advanced across the
anterior chamber of the eye and that a distal portion of the device
is fitted within an anterior chamber angle of the eye, and is
thereby properly positioned for deployment of the intraocular
shunt.
[0018] Another aspect of some embodiments provides methods for
deploying a shunt within an eye including inserting into an eye a
deployment device configured to hold an intraocular shunt,
advancing the device until a protrusion on a distal end of a
housing of the device contacts an anterior chamber angle of the
eye, thereby providing resistance against further advancement of
the device, and deploying the shunt from the device. In certain
embodiments, a distal portion of the housing comprises a sleeve and
a hollow shaft that is movable within the sleeve.
[0019] In certain embodiments, some devices include a housing
having an angled distal end, a deployment mechanism at least
partially disposed within the housing, and a hollow shaft coupled
to the deployment mechanism, in which the shaft is configured to
hold an intraocular shunt. Some devices may further include an
intraocular shunt that is at least partially disposed within the
shaft. In particular embodiments, the angle of the distal end is
substantially identical to an anterior chamber angle of an eye.
[0020] The housing of some devices may include a proximal portion
and a distal portion. In certain embodiments, the distal portion of
the housing is movable within the proximal portion of the housing.
The housing may further include a member that limits axial
retraction of the distal portion of the housing.
[0021] In certain embodiments, the distal portion includes a
capsule and a sleeve. In other embodiments, a distal end of the
sleeve further includes a protrusion. The protrusion may be formed
integrally with the distal end of the sleeve or may be connected to
a distal end of the sleeve. The protrusion may surround the distal
end of the sleeve, or the protrusion may extend around only a
portion of the sleeve. In certain embodiments, the protrusion is a
collar that surrounds the distal end of the sleeve. In other
embodiments, the protrusion includes a flat bottom portion and an
angled top portion. In particular embodiments, the angle of the top
portion is substantially identical to an anterior chamber angle of
an eye.
[0022] Some methods and devices are typically conducted using an ab
interno approach. Such an approach is contrasted with an ab externo
approach, which involves inserting a deployment device through the
conjunctiva of the eye. Although, some methods may be conducted
using an ab externo approach.
[0023] Some methods may be performed such that the distal portion
of the deployment device or shaft is inserted above or below the
corneal limbus. Some methods may be performed such that the distal
portion of the deployment device or shaft is inserted into the eye
without removing an anatomical feature of the eye, such as the
trabecular meshwork, the iris, the cornea, and the aqueous humor.
In certain embodiments, some methods may be conducted without
inducing substantial ocular inflammation such as, for example,
subconjunctival blebbing or endophthalmitis.
[0024] The deployment configuration involves engagement of the
deployment mechanism. In certain embodiments, the deployment
mechanism may include a two stage system. The first stage is a
pusher component and the second stage is a retraction component.
Rotation of the deployment mechanism sequentially engages the
pusher component and then the retraction component. The pusher
component pushes the shunt to partially deploy the shunt from
within the shaft, and the retraction component retracts the shaft
from around the shunt. The deployment mechanism further includes at
least one member that limits axial movement of the shaft.
[0025] The hollow shaft of the deployment device may have various
shapes and sizes. In certain embodiments, a distal end of the shaft
is beveled. In particular embodiments, the bevel is a double bevel.
In certain embodiments, the angle of the bevel is such that upon
insertion of the shaft through the sclera of an eye, the bevel is
substantially parallel with the conjunctiva of an eye. In certain
embodiments, the hollow shaft is a needle.
[0026] Some devices may be completely automated, partially
automated, or completely manual. Some devices may be connected to
larger robotic systems or may be used as stand-alone handheld
deployment devices. In particular embodiments, the device is a
handheld device.
[0027] Some devices may include an indicator that provides feedback
to an operator as to the state of the deployment mechanism. The
indicator may be any type of indicator known in the art, for
example a visual indicator, an audio indicator, or a tactile
indicator. In certain embodiments, the indicator is a visual
indicator.
[0028] Other aspects of some embodiments provide devices for
deploying an intraocular shunt that include a housing, in which a
distal end of the housing includes a protrusion, a deployment
mechanism at least partially disposed within the housing, and a
hollow shaft coupled to the deployment mechanism, in which the
shaft is configured to hold an intraocular shunt. The devices may
further include an intraocular shunt that is at least partially
disposed within the shaft.
[0029] Another aspect of some embodiments provides devices for
deploying an intraocular shunt that include a deployment mechanism,
a hollow shaft coupled to the deployment mechanism and configured
to hold an intraocular shunt, and a member adapted to provide
resistance feedback to an operator upon a distal portion of the
device contacting an anatomical feature of the eye, such as the
sclera. The resistance feedback indicates to an operator that a
distal portion of the device is properly positioned to deploy the
shunt.
[0030] Another aspect of some embodiments provides devices for
deploying an intraocular shunt that include a deployment mechanism,
a hollow shaft coupled to the deployment mechanism and configured
to hold an intraocular shunt, and means for providing feedback to
an operator advancing the shaft. The feedback indicates to an
operator that a distal portion of the shaft is properly positioned
to deploy the shunt. In certain embodiments, the feedback is
resistance feedback.
[0031] Other aspects of some embodiments provide devices for
deploying an intraocular shunt including a housing having a
proximal portion and a distal portion, in which the distal portion
is movable within the proximal portion, a deployment mechanism at
least partially disposed within the housing, and a hollow shaft
coupled to the deployment mechanism, in which the shaft is
configured to hold an intraocular shunt. The devices may further
include an intraocular shunt that is at least partially disposed
within the shaft.
[0032] Some devices include numerous configurations, such as an
insertion configuration, a shaft exposure configuration, and a
deployment configuration. The insertion configuration includes the
hollow shaft fully disposed within the sleeve. The shaft exposure
configuration includes retraction of the capsule to at least
partially within the proximal portion of the housing, thereby
exposing a distal portion of the hollow shaft from the sleeve.
[0033] Other aspects of some embodiments provide devices for
deploying an intraocular shunt that includes a housing, a
deployment mechanism at least partially disposed within the
housing, and a hollow shaft coupled inside the housing to the
deployment mechanism, in which the shaft is configured to hold an
intraocular shunt. These devices include an insertion configuration
and a deployment configuration and the insertion configuration
involves the shaft being fully disposed within the housing. The
devices may further include an intraocular shunt that is at least
partially disposed within the shaft.
[0034] Further, some embodiments relate to eliminating or at least
minimizing damage to the eye of a patient during an intraocular
shunt placement procedure. Intraocular shunts are typically
deployed into the eye using a deployment device that includes or is
coupled to a hollow shaft, such as a needle, that holds the
intraocular shunt. The hollow shaft of the deployment device is
inserted into the eye, then the shunt is deployed into the eye from
the deployment device. Once inserted into the eye, the interaction
between the hollow shaft of the deployment device and surrounding
eye tissue oftentimes causes the shaft to become stuck in the
surrounding eye tissue (due to frictional resistance, for example),
which can cause severe eye trauma upon shunt deployment or
withdrawal of the shaft from the eye. This trauma is avoided or at
least minimized in some embodiments by loosening the hollow shaft
from the surrounding eye tissue prior to deploying the shunt into
the eye from the deployment device and/or withdrawing the hollow
shaft from the eye.
[0035] The present inventions provide improved methods for
implantation of intraocular shunts. In one aspect, some methods
involve the insertion into the eye of a portion of a deployment
device comprising an intraocular shunt, loosening the portion of
deployment device from the surrounding eye tissue, deploying the
shunt into the eye from the deployment device, then withdrawing the
portion of the deployment device from the eye. In one particular
embodiment, the methods involve inserting into the eye a portion of
a deployment device comprising an intraocular shunt without
removing an anatomical feature of the eye, loosening the portion of
the deployment device from the surrounding eye tissue, deploying
the shunt into the eye from the deployment device, then withdrawing
the portion of the deployment device from the eye. Loosening of the
portion of the deployment device inserted into the eye from the
surrounding eye tissue can be achieved, for example, by rotating
the deployment device or a portion of the deployment device, other
than the portion inserted into the eye. Rotation of the deployment
device, or portion thereof, causes the portion of the deployment
device inserted into the eye to also rotate, thereby loosening the
deployment device from the surrounding eye tissue. Examples of eye
tissue surrounding the portion of the deployment device inserted
into the eye include, without limitation, the scleral tissue and/or
the trabecular meshwork.
[0036] The loosening and deployment steps of some methods do not
have to be conducted in any particular order. For example, some
methods may involve inserting into the eye a portion of a
deployment device comprising an intraocular shunt, deploying the
shunt into the eye from the deployment device, loosening the
portion of the deployment device from the surrounding eye tissue,
then withdrawing the portion of the deployment device from the
eye.
[0037] The deployment device may be configured such that a proximal
portion of the deployment device is rotated to loosen the portion
of the deployment device in the eye from the surrounding eye tissue
before or after deploying the shunt into the eye. Alternatively,
the deployment device may be configured such that a distal portion
of the deployment device is rotated to loosen the portion of the
deployment device in the eye from the surrounding eye before or
after deploying the shunt into the eye. In yet another embodiment,
the entire deployment device may be rotated to loosen the portion
of the deployment device in the eye from the surrounding eye tissue
before or after deploying the shunt into the eye. Preferably, the
deployment device, or a portion thereof, is rotated about its
longitudinal axis. Rotation can be in a clockwise or
counterclockwise direction.
[0038] In another aspect, the present inventions relate to methods
for implanting an intraocular shunt into an eye by inserting into
the eye a portion of a deployment device comprising an intraocular
shunt, whereby insertion into the eye is at an angle above or below
the corneal limbus, rather than through the corneal limbus.
Preferably, the portion of the deployment device is inserted into
the eye at an angle above the corneal limbus. For example, a
portion of a deployment device comprising an intraocular shunt is
inserted into the eye approximately 1 mm to 2 mm above the corneal
limbus, or any specific value within said range, e.g., 1 mm, 1.1
mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm
or 2 mm above the corneal limbus. The shunt is then deployed into
the eye from the deployment device, and the portion of the
deployment device is withdrawn from the eye. Shunt implantation
methods above or below the corneal limbus are preferably coupled
with the step of loosening the deployment device from the
surrounding eye tissue before or after deploying the shunt into the
eye, as previously described.
[0039] Preferably, some methods are conducted using an ab interno
approach by inserting a portion of a deployment device comprising
an intraocular shunt through the cornea, across the anterior
chamber, through the sclera and into an aqueous humor drainage
structure such as the intra-Tenon's space, the subconjunctival
space, the episcleral vein the suprachoroidal space or Schlemm's
canal. Such an approach is contrasted with an ab externo approach,
which may also be used, and which involves inserting the portion of
the deployment device comprising an intraocular shunt from the
outside of the eye through the conjunctiva and inward through the
sclera to reach a drainage structure such as Schlemm's canal.
Although, some methods may be conducted using an ab externo
approach.
[0040] In other certain embodiments, some methods are conducted
without the use of an optical apparatus, particularly an optical
apparatus that directly contacts the eye, such as a goniolens. In
yet other certain embodiments, some methods are conducted using an
optical apparatus that does not directly contact the eye, such as
an ophthalmic microscope.
[0041] In a particular embodiment, some methods are reversible.
That is, intraocular shunts that are implanted into the eye in
accordance with some methods can be removed from the eye and a
second shunt can be implanted in the eye.
[0042] Deployment of an intraocular shunt into the eye in
accordance with some methods results in the formation of a passage
that directs aqueous humor fluid flow from an area of high pressure
in the eye, typically the anterior chamber, to an area of lower
pressure within the eye, such as the intra-Tenon's space, the
subconjunctival space, the episcleral vein, the suprachoroidal
space or Schlemm's canal. Alternatively, the shunt is deployed in
accordance with some methods such that it form a passage that
directs aqueous humor fluid flow from an area of high pressure,
such as the anterior chamber, to an area of lower pressure within
the head, such as the subarachnoid space. In a preferred
embodiment, deployment of an intraocular shunt in accordance with
some methods results in the formation of a passage that directs
aqueous humor fluid flow from the anterior chamber of the eye to
the intra-Tenon's space.
[0043] The present inventions generally relate to methods for
deploying intraocular shunts into the subconjunctival space the eye
while avoiding or minimizing contact with the conjunctiva. In
particular, the present inventions provide methods for deploying an
intraocular shunt into the eye such that the shunt forms a drainage
pathway from the anterior chamber of the eye to the region of the
eye that is bound between the sclera and Tenon's capsule, referred
to herein as the intra-Tenon's space. Deployment of an intraocular
shunt such that the shunt inlet (i.e., the portion of the shunt
that receives fluid from an anterior chamber of the eye) terminates
in the anterior chamber and the shunt outlet (i.e., the portion of
the shunt that directs fluid to the intra-Tenon's space) terminates
in the intra-Tenon's space safeguards the integrity of the
conjunctiva to allow subconjunctival drainage pathways to
successfully form.
[0044] Some methods involve inserting into the eye a hollow shaft
that is configured to hold an intraocular shunt, deploying the
shunt from the shaft such that the shunt forms a passage from the
anterior chamber to the intra-Tenon's space, and withdrawing the
hollow shaft from the eye. The hollow shaft may hold the shunt
within the interior of hollow shaft. Alternatively, the hollow
shaft may hold the shunt on an outer surface of the shaft. In
certain embodiments, some methods involve the use of a hollow shaft
configured to hold an intraocular shunt, as previously described,
wherein a portion of the hollow shaft extends linearly along a
longitudinal axis and at least one other portion of the shaft
extends off the longitudinal axis, to insert and deploy the
intraocular shunt into the eye such that the shunt forms a passage
from the anterior chamber to the intra-Tenon's space.
[0045] Optionally, an aqueous fluid is injected into the eye
simultaneously with or prior to the insertion and deployment steps
of some methods. For example, an aqueous solution may be injected
below Tenon's capsule to balloon the capsule away from the sclera
and allow positioning of the intraocular shunt in the intra-Tenon's
space.
[0046] In certain aspects, the present inventions generally provide
shunts composed of a material that has an elasticity modulus that
is compatible with an elasticity modulus of tissue surrounding the
shunt. In this manner, some embodiments of the shunt are
flexibility matched with the surrounding tissue, and thus will
remain in place after implantation without the need for any type of
anchor that interacts with the surrounding tissue. Consequently,
some embodiments of the shunt will maintain fluid flow away for an
anterior chamber of the eye after implantation without causing
irritation or inflammation to the tissue surrounding the eye.
[0047] Although discussed in the context of the eye, the elasticity
modulus of the shunt may be matched to the elasticity modulus of
any tissue. Thus, some embodiments of the shunt may be used to
drain fluid from any organ. In particular embodiments, the organ is
an eye. Some embodiments of the shunt may define a flow path from
an area of high pressure in the eye (e.g., an anterior chamber) to
an area of lower pressure in the eye (e.g., intra-Tenon's space,
the subconjunctival space, the episcleral vein, the suprachoroidal
space, and Schlemm's canal).
[0048] In other aspects, the present inventions generally provide
shunts in which a portion of the shunt is composed of a flexible
material that is reactive to pressure, i.e., an inner diameter of
the shunt fluctuates depending upon the pressures exerted on that
portion of the shunt. Thus, the flexible portion of the shunt acts
as a valve that regulates fluid flow through the shunt. After
implantation, intraocular shunts have pressure exerted upon them by
tissues surrounding the shunt (e.g., scleral tissue) and pressure
exerted upon them by aqueous humor flowing through the shunt. When
the pressure exerted on the flexible portion of the shunt by the
surrounding tissue is greater than the pressure exerted on the
flexible portion of the shunt by the fluid flowing through the
shunt, the flexible portion decreases in diameter, restricting flow
through the shunt. The restricted flow results in aqueous humor
leaving the anterior chamber at a reduced rate.
[0049] When the pressure exerted on the flexible portion of the
shunt by the fluid flowing through the shunt is greater than the
pressure exerted on the flexible portion of the shunt by the
surrounding tissue, the flexible portion increases in diameter,
increasing flow through the shunt. The increased flow results in
aqueous humor leaving the anterior chamber at an increased
rate.
[0050] The flexible portion of the shunt may be any portion of the
shunt. In certain embodiments, the flexible portion is a distal
portion of the shunt. In certain embodiments, the entire shunt is
composed of the flexible material.
[0051] Other aspects of the present inventions generally provide
multi-port shunts. Such shunts reduce probability of the shunt
clogging after implantation because fluid can enter or exit the
shunt even if one or more ports of the shunt become clogged with
particulate. In certain embodiments, the shunt includes a hollow
body defining a flow path and more than two ports, in which the
body is configured such that a proximal portion receives fluid from
the anterior chamber of an eye and a distal portion directs the
fluid to a location of lower pressure with respect to the anterior
chamber.
[0052] The shunt may have many different configurations. In certain
embodiments, the proximal portion of the shunt (i.e., the portion
disposed within the anterior chamber of the eye) includes more than
one port and the distal portion of the shunt (i.e., the portion
that is located in an area of lower pressure with respect to the
anterior chamber such as intra-Tenon's space, the subconjunctival
space, the episcleral vein, the suprachoroidal space, or Schlemm's
canal) includes a single port. In other embodiments, the proximal
portion includes a single port and the distal portion includes more
than one port. In still other embodiments, the proximal and the
distal portions include more than one port.
[0053] The ports may be positioned in various different
orientations and along various different portions of the shunt. In
certain embodiments, at least one of the ports is oriented at an
angle to the length of the body. In certain embodiments, at least
one of the ports is oriented 90.degree. to the length of the
body.
[0054] The ports may have the same or different inner diameters. In
certain embodiments, at least one of the ports has an inner
diameter that is different from the inner diameters of the other
ports.
[0055] Other aspects of the present inventions generally provide
shunts with overflow ports. Those shunts are configured such that
the overflow port remains closed until there is a pressure build-up
within the shunt sufficient to force open the overflow port. Such
pressure build-up typically results from particulate partially or
fully clogging an entry or an exit port of the shunt. Such shunts
reduce probability of the shunt clogging after implantation because
fluid can enter or exit the shunt by the overflow port even if one
port of the shunt becomes clogged with particulate.
[0056] In certain embodiments, the shunt includes a hollow body
defining an inlet configured to receive fluid from an anterior
chamber of the eye and an outlet configured to direct the fluid to
a location of lower pressure with respect to the anterior chamber,
the body further including at least one slit. The slit may be
located at any place along the body of the shunt. In certain
embodiments, the slit is located in proximity to the inlet. In
other embodiments, the slit is located in proximity to the outlet.
In certain embodiments, there is a slit in proximity to both the
inlet and the outlet of the shunt.
[0057] In certain embodiments, the slit has a width that is
substantially the same or less than an inner diameter of the inlet.
In other embodiments, the slit has a width that is substantially
the same or less than an inner diameter of the outlet. Generally,
the slit does not direct the fluid unless the outlet is obstructed.
However, the shunt may be configured such that the slit does direct
at least some of the fluid even if the inlet or outlet is not
obstructed.
[0058] In other aspects, the present inventions generally provide a
shunt having a variable inner diameter. In particular embodiments,
the diameter increases from inlet to outlet of the shunt. By having
a variable inner diameter that increases from inlet to outlet, a
pressure gradient is produced and particulate that may otherwise
clog the inlet of the shunt is forced through the inlet due to the
pressure gradient. Further, the particulate will flow out of the
shunt because the diameter only increases after the inlet.
[0059] In certain embodiments, the shunt includes a hollow body
defining a flow path and having an inlet configured to receive
fluid from an anterior chamber of an eye and an outlet configured
to direct the fluid to a location of lower pressure with respect to
the anterior chamber, in which the body further includes a variable
inner diameter that increases along the length of the body from the
inlet to the outlet. In certain embodiments, the inner diameter
continuously increases along the length of the body. In other
embodiments, the inner diameter remains constant along portions of
the length of the body. Exemplary locations of lower pressure
include the intra-Tenon's space, the subconjunctival space, the
episcleral vein, the subarachnoid space, and Schlemm's canal.
[0060] In certain embodiments, some embodiments of the shunt may be
coated or impregnated with at least one pharmaceutical and/or
biological agent or a combination thereof. The pharmaceutical
and/or biological agent may coat or impregnate an entire exterior
of the shunt, an entire interior of the shunt, or both.
Alternatively, the pharmaceutical and/or biological agent may coat
and/or impregnate a portion of an exterior of the shunt, a portion
of an interior of the shunt, or both. Methods of coating and/or
impregnating an intraocular shunt with a pharmaceutical and/or
biological agent are known in the art. See, for example, Darouiche
(U.S. Pat. Nos. 7,790,183; 6,719,991; 6,558,686; 6,162,487;
5,902,283; 5,853,745; and 5,624,704) and Yu et al. (U.S. Pat. Pub.
No. 2008/0108933). The content of each of these references is
incorporated by reference herein its entirety.
[0061] In certain embodiments, the exterior portion of the shunt
that resides in the anterior chamber after implantation (e.g.,
about 1 mm of the proximal end of the shunt) is coated and/or
impregnated with the pharmaceutical or biological agent. In other
embodiments, the exterior of the shunt that resides in the scleral
tissue after implantation of the shunt is coated and/or impregnated
with the pharmaceutical or biological agent. In other embodiments,
the exterior portion of the shunt that resides in the area of lower
pressure (e.g., the intra-Tenon's space or the subconjunctival
space) after implantation is coated and/or impregnated with the
pharmaceutical or biological agent. In embodiments in which the
pharmaceutical or biological agent coats and/or impregnates the
interior of the shunt, the agent may be flushed through the shunt
and into the area of lower pressure (e.g., the intra-Tenon's space
or the subconjunctival space).
[0062] Any pharmaceutical and/or biological agent or combination
thereof may be used with some embodiments of the shunt. The
pharmaceutical and/or biological agent may be released over a short
period of time (e.g., seconds) or may be released over longer
periods of time (e.g., days, weeks, months, or even years).
Exemplary agents include anti-mitotic pharmaceuticals such as
Mitomycin-C or 5-Fluorouracil, anti-VEGF (such as Lucintes,
Macugen, Avastin, VEGF or steroids).
[0063] The shunts discussed above and herein are described relative
to the eye and, more particularly, in the context of treating
glaucoma and solving the above identified problems relating to
intraocular shunts. Nonetheless, it will be appreciated that shunts
described herein may find application in any treatment of a body
organ requiring drainage of a fluid from the organ and are not
limited to the eye.
[0064] The present inventions provide devices and methods for
self-guided implantation of soft gel tissue compliant intraocular
shunts in the suprachoroidal space. Shunt placement in the
suprachoroidal space avoids contact with the conjunctiva, thus
safeguarding the integrity of the conjunctiva. Implanting shunts
made of soft, tissue compliant material avoid the creation of a
cyclodialysis cleft and reduces or eliminates the risk of hypotony
and related side effects.
[0065] Some embodiments of the device accomplish self-guided shunt
deployment in the suprachoroidal space by having a flexible hollow
shaft with a bend that biases the shunt to follow the scleral spur
as it is deployed from the shaft. The hollow shaft is pre-bent to
match the angle or arc of the sclera. In a pre-deployment
configuration, the shaft is disposed within the device. The
rigidity of the device holds the hollow shaft in a straight
configuration. Upon its exposure from the device, the hollow shaft
reverts to its pre-bent configuration. Such a pre-bend allows the
hollow shaft to follow the scleral spur down along the sclera in a
self-guided manner to the suprachoroidal space. Additionally, the
flexibility of the hollow shaft allows it to continually bend and
flex in response to the anatomy as the hollow shaft advances from
the device. Once properly positioned, the shunt is deployed from
the shaft. The bend in the shaft self-guides the shunt along the
scleral spur of the eye as the shaft is retracted into the device
and the shunt is deployed from the shaft.
[0066] In certain aspects, some embodiments of the device also
include a housing and a deployment mechanism at least partially
disposed in the housing. In certain embodiments, the hollow shaft
is coupled to the deployment mechanism. The housing may include two
components, a proximal portion and a distal portion. The components
are configured such that the distal portion is movable within the
proximal portion. In certain embodiments, the distal portion of the
housing includes a stiff sleeve and the shaft is movably disposed
within the sleeve. In other embodiments, the distal portion is
without a stiff outer sleeve. As previously described, the shaft is
flexible and pre-bent to match an angle of the sclera. In certain
embodiments, the distal end of the hollow shaft includes a sharp
tip to assist in piercing the sclera. In certain embodiments, the
hollow shaft is a flexible needle.
[0067] In other embodiments, a distal end of the sleeve further
includes a protrusion. The protrusion may be formed integrally with
the distal end of the sleeve or may be connected to a distal end of
the sleeve. The protrusion may surround the distal end of the
sleeve, or the protrusion may extend around only a portion of the
sleeve. In certain embodiments, the protrusion is a collar that
surrounds the distal end of the sleeve. In other embodiments, the
protrusion includes a flat bottom portion and an angled top
portion. In particular embodiments, the angle of the top portion is
substantially identical to an anterior chamber angle of an eye.
[0068] Other aspects of some embodiments provide for methods of
using the above described devices for inserting a intraocular shunt
into the suprachoroidal space of an eye. Such methods involve
inserting the above device into an eye and deploying a shunt from
the device within the eye such that a proximal portion of the shunt
receives fluid from an anterior chamber of an eye and a distal
portion of the shunt directs the fluid to the suprachoroidal space.
Some methods may also involve injecting a drug into the
suprachoroidal space prior to deploying the shunt from the device.
Exemplary drugs include drug is a BSS/steroids or antifibrotic
agents.
BRIEF DESCRIPTION OF THE DRAWINGS
[0069] FIG. 1 provides a cross-sectional diagram of the general
anatomy of the eye.
[0070] FIG. 2 provides another cross-sectional view the eye, and
certain anatomical structures of the eye.
[0071] FIG. 3 depicts, implantation of an intraocular shunt with a
distal end of a deployment device holding a shunt, shown in
cross-section.
[0072] FIGS. 4A-4B depict a deployment device having a plunger type
mechanism for deploying an intraocular shunt into the eye.
[0073] FIG. 5 depicts an example of a deployment device configured
to hold an intraocular shunt.
[0074] FIG. 6A depicts a hollow shaft having a bend in a distal
portion of the shaft.
[0075] FIG. 6B depicts a hollow shaft having a U-shape.
[0076] FIG. 6C depicts a hollow shaft having a V-shape.
[0077] FIG. 7A depicts a simulation of the exit site distance from
the limbus and height above the iris after needle entry at the
limbus using an ab interno procedure.
[0078] FIG. 7B depicts a simulation of the exit site distance from
the limbus and height above the iris after needle entry above the
limbus using an ab interno procedure.
[0079] FIGS. 8 and 9 show an intraocular shunt deployed within the
eye. A proximal portion of the shunt resides within the
intra-Tenon's space. A middle portion of the shunt resides in the
sclera.
[0080] FIG. 10A depicts the tip bevel portion of a triple-ground
needle tip.
[0081] FIG. 10B depicts the flat bevel portion of a triple-ground
needle tip.
[0082] FIG. 10C depicts an intraocular shunt within a triple-ground
needle tip.
[0083] FIG. 10D depicts 100% penetration of the flat bevel portion
of a triple-ground needle tip through the sclera of an eye.
[0084] FIG. 11A depicts an intraocular shunt inserted into the
scleral channel using a beveled needle tip to completely penetrate
the scleral tissue prior to insertion of the shunt.
[0085] FIG. 11B depicts an intraocular shunt inserted into the
scleral channel using a beveled needle tip to partially penetrate
the scleral tissue prior to insertion of the shunt.
[0086] FIG. 12 provides a schematic of a shunt having a flexible
portion.
[0087] FIGS. 13A-13C provide schematics of a shunt implanted into
an eye for regulation of fluid flow from the anterior chamber of
the eye to a drainage structure of the eye.
[0088] FIGS. 14A-14C show different embodiments of multi-port
shunts. FIG. 14A shows an embodiment of a shunt in which the
proximal portion of the shunt includes more than one port and the
distal portion of the shunt includes a single port.
[0089] FIG. 14B shows another embodiment of a shunt in which the
proximal portion includes a single port and the distal portion
includes more than one port.
[0090] FIG. 14C shows another embodiment of a shunt in which the
proximal portions include more than one port and the distal
portions include more than one port.
[0091] FIGS. 15A and 15B show different embodiments of multi-port
shunts having different diameter ports.
[0092] FIGS. 16A-16C provide schematics of shunts having a slit
located along a portion of the length of the shunt.
[0093] FIG. 17 depicts a shunt having multiple slits along a length
of the shunt.
[0094] FIG. 18 depicts a shunt having a slit at a proximal end of
the shunt.
[0095] FIGS. 19A and 19B show schematics of shunt that have a
variable inner diameter.
[0096] FIGS. 20A-20D depict a shunt having multiple prongs at a
distal and/or proximal end.
[0097] FIGS. 21A-21D depict a shunt having a longitudinal slit at a
distal and/or proximal end.
[0098] FIG. 22A is a schematic showing an embodiment of a shunt
deployment device according to some embodiments.
[0099] FIG. 22B shows a cross sectional view of the device of FIG.
22A. In this figure, the distal portion of the housing is extended
from the proximal portion of the housing.
[0100] FIG. 22C shows a cross sectional view of the device of FIG.
22A. In this figure, the distal portion of the housing is retracted
within the proximal portion of the housing.
[0101] FIG. 22D shows another cross sectional view of an embodiment
of the device of FIG. 22A.
[0102] FIG. 22E is a schematic showing an enlarged view of a
protrusion on a distal end of a distal portion of a housing of the
device of FIG. 22A. In this figure, a bottom portion of the
protrusion is flat and a top portion of the protrusion is
angled.
[0103] FIGS. 23A-23C are schematics showing an enlarged view of a
protrusion on a distal end of a distal portion of a housing of some
embodiments of the device.
[0104] FIG. 23B is a side view of the protrusion shown in FIG.
23A.
[0105] FIG. 23C is a top view of the protrusion shown in FIG.
23A.
[0106] FIG. 24A shows a deployment device in an insertion
configuration and fit into an anterior chamber of an eye.
[0107] FIG. 24B shows a deployment device in an insertion
configuration and inserted at too shallow an angled, thus abutting
the sclera above the anterior chamber angle.
[0108] FIG. 24C shows a deployment device in an insertion
configuration after the protrusion has caused the device to slide
down the sclera and be fit into an anterior chamber of an eye.
[0109] FIG. 24D shows a deployment device in an insertion
configuration and inserted at too steep an angled, thus abutting
the iris below the anterior chamber angle.
[0110] FIG. 24E shows a deployment device in an insertion
configuration after the protrusion has caused the device to deflect
off of the iris and slide along the iris and be fit into an
anterior chamber of an eye.
[0111] FIG. 25 is a schematic showing an embodiment of a shunt
deployment device according to some embodiments.
[0112] FIG. 26 shows an exploded view of the device shown in FIG.
25.
[0113] FIGS. 27A-27D are schematics showing different enlarged
views of the deployment mechanism of the deployment device with the
shaft in a straight configuration, as if the shaft is within the
stiff outer sleeve.
[0114] FIGS. 28A-28C are schematics showing interaction of the
deployment mechanism with a portion of the housing of the
deployment device.
[0115] FIG. 28C shows the shaft in a straight configuration, as if
it is within the stiff outer sleeve.
[0116] FIG. 29 depicts a schematic of an exemplary intraocular
shunt.
[0117] FIG. 30 shows a cross sectional view of the deployment
mechanism of the deployment device with the shaft in a straight
configuration, as if the shaft is within the stiff outer
sleeve.
[0118] FIG. 31A is a schematic showing deployment some embodiments
of the device in a pre-deployment or insertion configuration.
[0119] FIG. 31B shows an enlarged view of the distal portion of the
deployment device of FIG. 31A. This figure shows an intraocular
shunt loaded within a hollow shaft of the deployment device and
that the shaft is completely disposed within the sleeve of the
housing. In this configuration, the hollow shaft is straight.
[0120] FIG. 31C show a schematic of the deployment mechanism in a
pre-deployment or insertion configuration.
[0121] FIG. 31D is another schematic showing deployment some
embodiments of the device in a pre-deployment or insertion
configuration.
[0122] FIGS. 32A-32B are schematics showing insertion of a device
into an anterior chamber of the eye, according to some embodiments.
FIG. 32A is a magnified view of the position of the distal portion
of the device relative to the proximal portion of the device in the
insertion configuration. FIG. 32B is a magnified view of the sleeve
of the device inserted into the eye. This figure also shows the
sleeve and protrusion fitted within an anterior chamber angle of
the eye.
[0123] FIG. 33A is a schematic showing extension of the shaft from
within the sleeve, which is accomplished by partial retraction of
the distal portion of housing to within the proximal portion of
housing.
[0124] FIG. 33B is a magnified view of the sleeve of the device
inserted into the eye, following a procedure as shown in FIG.
33A.
[0125] FIGS. 34A-34B show schematics of the deployment mechanism at
the end of the first stage of deployment of the shunt from the
deployment device with the shaft in a straight configuration, as if
the shaft is within the stiff outer sleeve.
[0126] FIG. 34C shows an enlarged view of the distal portion of the
deployment device of FIG. 34A. This figure shows an intraocular
shunt partially deployed from within a hollow shaft of the
deployment device.
[0127] FIG. 34D shows an enlarged view of the distal portion of the
deployment device of FIG. 34A, in which the shaft is shown exposed
from the sleeve and is in a bent configuration. This figure shows
an intraocular shunt partially deployed from within a hollow shaft
of the deployment device.
[0128] FIG. 35A-35B are schematics showing the deployment device
after completion of the first stage of deployment of the shunt from
the device and in to the eye. FIG. 35A is a magnified view of the
position of the distal portion of the device relative to the
proximal portion of the device. FIG. 35B is a magnified view of the
sleeve of the device inserted into the eye and the shaft extended
from the sleeve.
[0129] FIG. 36A show a schematic of the deployment mechanism at the
end of the second stage of deployment.
[0130] FIG. 36B shows another schematic of the deployment device at
the end of the second stage of deployment.
[0131] FIG. 36C is a magnified view of the sleeve of the device
inserted into the eye, retraction of the shaft into the sleeve, and
the shunt being deployed from the sleeve.
[0132] FIG. 36D shows another view of the deployment device at the
end of the second stage of deployment.
[0133] FIG. 37A is a schematic showing the deployment device after
completion of deployment of the shunt from the device and in to the
eye.
[0134] FIG. 37B is a magnified view of the sleeve of the device
being removed from the eye.
[0135] FIGS. 38A-38E show an intraocular shunt being deployed
within the eye, according to another embodiment.
DETAILED DESCRIPTION
[0136] The present inventions generally relate to methods for
treating closed angle glaucoma that involve using a deployment
device that is configured to both re-open a partially or completely
closed anterior chamber angle and deploy an intraocular shunt. In
certain aspects, some methods involve inserting into an eye a
deployment device configured to hold an intraocular shunt, using
the device to re-open an at least partially closed anterior chamber
angle of an eye, and deploying the shunt from the device.
[0137] FIG. 1 provides a schematic diagram of the general anatomy
of the eye. An anterior aspect of the anterior chamber 1 of the eye
is the cornea 2, and a posterior aspect of the anterior chamber 1
of the eye is the iris 4. Beneath the iris 4 is the lens 5. The
anterior chamber 1 is filled with aqueous humor 3. The aqueous
humor 3 drains into a space(s) 6 below the conjunctiva 7 through
the trabecular meshwork (not shown in detail) of the sclera 8. The
aqueous humor is drained from the space(s) 6 below the conjunctiva
7 through a venous drainage system (not shown).
[0138] FIG. 2 provides a cross-sectional view of a portion of the
eye, and provides greater detail regarding certain anatomical
structures of the eye. In particular, FIG. 2 shows the relationship
of the conjunctiva 12 and Tenon's capsule 13. Tenon's capsule 13 is
a fascial layer of connective tissue surrounding the globe and
extra-ocular muscles. As shown in FIG. 2, it is attached anteriorly
to the limbus of the eye and extends posteriorly over the surface
of the globe until it fuses with the dura surrounding the optic
nerve. In FIG. 2, number 9 denotes the limbal fusion of the
conjunctiva 12 and Tenon's capsule 13 to the sclera 11. The
conjunctiva 12 and Tenon's capsule 13 are separate membranes that
start at the limbal fusion 9 and connect to tissue at the posterior
of the eye. The space formed below the conjunctiva 12 is referred
to as the subconjunctival space, denoted as number 14. Below
Tenon's capsule 13 there are Tenon's adhesions that connect the
Tenon's capsule 13 to the sclera 11. The space between Tenon's
capsule 13 and the sclera 11 where the Tenon's adhesions connect
the Tenon's capsule 13 to the sclera 11 is referred to as the
intra-Tenon's space, denoted as number 10.
[0139] In conditions of glaucoma, the pressure of the aqueous humor
in the eye (anterior chamber) increases and this resultant increase
of pressure can cause damage to the vascular system at the back of
the eye and especially to the optic nerve. The treatment of
glaucoma and other diseases that lead to elevated pressure in the
anterior chamber involves relieving pressure within the anterior
chamber to a normal level.
[0140] Glaucoma filtration surgery is a surgical procedure
typically used to treat glaucoma. The procedure involves placing a
shunt in the eye to relieve intraocular pressure by creating a
pathway for draining aqueous humor from the anterior chamber of the
eye. The shunt is typically positioned in the eye such that it
creates a fluid-flow pathway between the anterior chamber of the
eye and a region of lower pressure. Various structures and/or
regions of the eye having lower pressure that have been targeted
for aqueous humor drainage include Schlemm's canal, the
subconjunctival space, the episcleral vein, the suprachoroidal
space, or the subarachnoid space. Methods of implanting intraocular
shunts are known in the art. Shunts may be implanted using an ab
externo approach (entering through the conjunctiva and inwards
through the sclera) or an ab interno approach (entering through the
cornea, across the anterior chamber, and through the trabecular
meshwork and sclera).
[0141] Ab interno approaches for implanting an intraocular shunts
have been described and may vary depending on the structure
targeted for aqueous humor drainage. For example, ab interno
approaches for implanting an intraocular shunt into the
subconjunctival space are shown in Yu et al. (U.S. Pat. No.
6,544,249 and U.S. Pat. Pub. No. 2008/0108933) and Prywes (U.S.
Pat. No. 6,007,511), the contents of each of which are incorporated
by reference herein in its entirety. Briefly and with reference to
FIG. 3, a surgical intervention to implant the shunt involves
inserting into the eye a portion of a deployment that holds an
intraocular shunt, and deploying the shunt within the eye 16. The
portion of the deployment device 15 holding the shunt enters the
eye 16 through the cornea 17 (ab interno approach). The portion of
the deployment device 15 is advanced across the anterior chamber 20
(as depicted by the broken line) in what is referred to as a
transpupil implant insertion. The portion of the deployment device
15 is advanced through the sclera 21 until a distal portion of the
device is in proximity to the subconjunctival space. The shunt is
then deployed from the deployment device, producing a conduit
between the anterior chamber and the subconjunctival space to allow
aqueous humor to drain through the conjunctival lymphatic
system.
[0142] Previously proposed deployment devices for implanting an
intraocular shunt into the eye, whether using an ab externo
procedure or an ab interno procedure, typically include a
plunger-type mechanism for deploying the shunt into the eye, such
as the deployment device illustrated in FIG. 3. The deployment
device in FIG. 3 is shown larger in FIG. 4A, and the distal portion
of the deployment device is shown magnified in FIG. 4B. As shown in
FIGS. 4A and 4B, the deployment device includes an assembly 20 that
includes a hollow shaft 22 defining an inner chamber 24. Placed
within the inner chamber 24 of the hollow shaft 22 is a cylindrical
inner tube or plunger 32 that is coaxial with the shaft 22. In the
loaded and ready to use condition, the intraocular shunt 26 is also
placed or otherwise disposed within the hollow inner chamber 24 of
the shaft 22 and is distally located relative to plunger 32. Both
the intraocular shunt 26 and plunger 32 may be placed over and
supported by optional guidewire 28. The intraocular shunt is
deployed into the eye by advancing the plunger to push the
intraocular shunt from the shaft into the eye. The shaft is then
withdrawn from the eye.
[0143] However, complications can arise when using such deployment
devices due to the frictional interaction between the deployment
device and the surrounding eye tissue that results upon insertion
of the deployment device into the eye and/or deployment of the
intraocular shunt into the eye from the deployment device. Moderate
to severe eye trauma can occur, beyond any trauma due to insertion
of the deployment device, if the portion of the deployment device
inserted into the eye is not loosened before or after deployment of
the intraocular shunt from the device and prior to withdrawing the
portion of the deployment device from the eye.
[0144] The present inventions provide improved methods for
implanting an intraocular shunt into the eye while avoiding or at
least minimizing the amount of trauma to the eye that is typically
involved with shunt implantation procedures. According to some
methods, any frictional resistance between the deployment device
and surrounding eye tissue that is created upon insertion of a
portion of a deployment device in the eye is resolved by loosening
the portion of the deployment device from the surrounding eye
tissue before or after deployment of the intraocular shunt from the
device and prior to withdrawing the portion of the deployment
device from the eye. The methods can be used in conjunction with
any known shunt deployment device, and in particular, any
deployment device that includes a portion for holding an
intraocular shunt or is coupled to a hollow shaft which is
configured to hold an intraocular shunt.
[0145] Preferably, at least a portion of the deployment device is
rotated before the shunt is deployed into the eye from the
deployment device, in order to loosen the portion of the device
inserted into the eye from the surrounding eye tissue prior to
withdrawing the deployment device from the eye. Rotation may be
clockwise or counterclockwise, and may be performed manually or in
an automated manner. Rotation of only a distal portion of the
deployment device may be sufficient to loosen the portion of the
deployment device in the eye from the surrounding eye tissue,
depending on the configuration of the device. Alternatively,
rotation of the entire deployment device serves to loosen the
portion of the deployment device in the eye from the surrounding
eye tissue. Rotation of the deployment device, or a portion
thereof, causes the portion of the deployment device that is
inserted into the eye to also rotate, thereby loosening the portion
of the deployment device in the eye form the surrounding eye
tissue. Examples of surrounding eye tissue include but are not
limited to the scleral tissue and the trabecular meshwork.
[0146] The deployment device, or a portion thereof, is rotated
clockwise or counterclockwise about the longitudinal axis of the
deployment device itself. The rotation about the longitudinal axis
is preferably between 1.degree. and 360.degree., or any specific
value within said range, e.g., 1.degree., 3.degree., 5.degree.,
10.degree., 15.degree., 30.degree., 45.degree., 60.degree.,
75.degree., 90.degree., 105.degree., 120.degree., 135.degree.,
150.degree. 165.degree., 180.degree., 195.degree., 210.degree.,
225.degree., 240.degree., 255.degree., 270.degree., 285.degree.,
300.degree., 315.degree., 330.degree., 345.degree. or
360.degree..
[0147] As previously stated, some methods can be used in
conjunction with any shunt deployment device. FIG. 5 provides an
exemplary schematic of a hollow shaft for use in conjunction with a
deployment device in accordance with some methods. This shows
hollow shaft 22 that is configured to hold an intraocular shunt 23.
The shaft may hold the shunt within the hollow interior 24 of the
shaft 22. Alternatively, the hollow shaft may hold the shunt on an
outer surface 25 of the shaft 22. In particular embodiments, the
shunt is held within the hollow interior 24 of the shaft 22.
Generally, in one embodiment, the intraocular shunts are of a
cylindrical shape and have an outside cylindrical wall and a hollow
interior. The shunt may have an inside diameter of approximately
10-250 microns, an outside diameter of approximately 190-300
microns, and a length of approximately 0.5 mm to 20 mm, such as,
for example, 6 mm to 14 mm. The hollow shaft 22 is configured to at
least hold a shunt of such shape and such dimensions. However, the
hollow shaft 22 may be configured to hold shunts of different
shapes and different dimensions than those described above, and
some embodiments encompass a shaft 22 that may be configured to
hold any shaped or dimensioned intraocular shunt.
[0148] In some embodiments, the hollow shaft for use in accordance
with some methods is straight along the entire length of the shaft.
Alternatively, a portion of the hollow shaft extends linearly along
a longitudinal axis and at least one other portion of the shaft
extends off the longitudinal axis. For example, the hollow shaft
may have a bend in the distal portion of the shaft, a U-shape, or
an arcuate or V-shape in at least a portion of the shaft. Examples
of such hollow shafts suitable for use with some methods include
but are not limited to the hollow shafts depicted in FIGS.
6A-6C.
[0149] Preferably, some methods are conducted by making an incision
in the eye prior to insertion of the deployment device configured
to hold the intraocular shunt. Although in particular embodiments,
some methods may be conducted without making an incision in the eye
prior to insertion of the deployment device configured to hold the
intraocular shunt. In certain embodiments, the distal end of the
deployment device (i.e. the portion that is inserted into the eye)
has a sharpened point or tip. For example, the distal end of the
deployment device includes or is coupled to a needle configured to
hold an intraocular shunt. Needles that are configured to hold an
intraocular shunt are commercially available from Terumo Medical
Corp. (Elkington Md.). In a particular embodiment, the distal end
of the deployment device is coupled to a needle having a hollow
interior and a beveled tip, and the intraocular shunt is held
within the hollow interior of the needle. In another particular
embodiment, the distal end of the deployment device is coupled to a
needle having a hollow interior and a triple ground point or
tip.
[0150] Some methods are preferably conducted without needing to
remove an anatomical portion or feature of the eye, including but
not limited to the trabecular meshwork, the iris, the cornea, or
aqueous humor. Some methods are also preferably conducting without
inducing substantial ocular inflammation, such as subconjunctival
blebbing or endophthalmitis. Such methods are preferably achieved
using an ab interno approach by inserting the deployment device
comprising the intraocular shunt through the cornea, across the
anterior chamber, through the trabecular meshwork and sclera and
into a drainage structure such as Schlemm's canal, the
subconjunctival space, the episcleral vein, the suprachoroidal
space, the intra-Tenon's space or the subarachnoid space. However,
some methods may be conducted using an ab externo approach.
[0151] When some methods are conducted using an ab interno
approach, the deployment device is preferably inserted into the eye
at an angle above or below the corneal limbus, inserted in contrast
with entering through the corneal limbus. Preferably, the
deployment device is inserted above the corneal limbus. For
example, the deployment device is inserted approximately 0.25 to
3.0 mm, preferably approximately 0.5 to 2.5 mm, more preferably
approximately 1.0 mm to 2.0 mm above the corneal limbus, or any
specific value within said ranges, e.g., approximately 1.0 mm,
approximately 1.1 mm, approximately 1.2 mm, approximately 1.3 mm,
approximately 1.4 mm, approximately 1.5 mm, approximately 1.6 mm,
approximately 1.7 mm, approximately 1.8 mm, approximately 1.9 mm or
approximately 2.0 mm above the corneal limbus.
[0152] Entering at an angle above or below the corneal limbus is
advantageous for placing the shunt farther from the limbus at the
exit site. It also adds more distance between the shunt and the
iris. FIG. 7A demonstrates the change in location of the shunt
sclera exit and the height above the iris in the chamber at
different angles of entry using a hollow needle configured to hold
an intraocular shunt.
[0153] Without intending to be bound by any theory, placement of
the shunt farther from the limbus at the exit site, as provided by
an angle of entry above the limbus, is believed to provide access
to more lymphatic channels for drainage of aqueous humor, such as
the episcleral lymphatic network, in addition to the conjunctival
lymphatic system. A higher angle of entry also results in flatter
placement in the intra-Tenon's space so that there is less bending
of the shunt, less pressure on Tenon's capsule, and subsequently
less erosion pressure on the conjunctiva via Tenon's capsule.
[0154] For example, as shown in FIG. 7A, shaft entry at the limbus
52 results in exit site distance 53 of approximately 1.6 mm from
the limbus, and very close proximity to the iris 4. Such placement
results in a large degree of bending of the shunt, resulting in
increased pressure on Tenon's capsule and subsequently on the
conjunctiva. In contrast, a high angle of entry 54 above the limbus
52 (e.g., 2 mm above the limbus 52), results in an exit site
distance 53 of approximately 2.1 mm from the limbus and a height
well above the iris 4, as shown in FIG. 7B. Such placement results
in flatter placement in the intra-Tenon's space so that there is
less bending of the shunt, less pressure on Tenon's capsule, and
subsequently less erosion pressure on the conjunctiva via Tenon's
capsule.
[0155] Deployment of an intraocular shunt in the eye in accordance
with some methods results in the formation of a passage that
directs fluid flow from an area of high pressure in the eye,
typically the anterior chamber, to an area of lower pressure within
the eye or within the head, to relieve or reduce intraocular
pressure. Areas of lower pressure within the eye that are suited
for aqueous humor drainage include but are not limited to the
intra-Tenon's space, the subconjunctival space, the episceleral
vein, the suprachoroidal space and Schlemm's canal. Alternatively,
the subarachnoid space may provide a drainage outlet for aqueous
humor from the anterior chamber. Preferably, deployment of the
shunt results in the formation of a passage for directing fluid
flow between the anterior chamber and the intra-Tenon's space.
[0156] Deployment of an intraocular shunt such that the inlet
(i.e., the portion of the shunt that receives fluid from an
anterior chamber of the eye) terminates in the anterior chamber and
the outlet (i.e., the portion of the shunt that directs fluid to
the intra-Tenon's space) terminates in the intra-Tenon's space
provides superior benefits over deployment generally in the
subconjunctival space. Deployment of the shunt outlet in the
intra-Tenon's space safeguards the integrity of the conjunctiva to
allow subconjunctival drainage pathways to successfully form. See,
for example, Yu et al., Progress in Retinal and Eye Research, 28:
303-328 (2009)). Additionally, drainage into the intra-Tenon's
space provides access to more lymphatic channels than just the
conjunctival lymphatic system, such as the episcleral lymphatic
network. Moreover, deployment of an intraocular shunt such that the
outlet terminates in the intra-Tenon's space avoids having to
pierce Tenon's capsule which can otherwise cause complications
during glaucoma filtration surgery due to its tough and fibrous
nature.
Methods for Intra-Tenon's Shunt Placement
[0157] Some methods involve inserting into the eye a hollow shaft
configured to hold an intraocular shunt. In certain embodiments,
the hollow shaft is a component of a deployment device that may
deploy the intraocular shunt. The shunt is then deployed from the
shaft into the eye such that the shunt forms a passage from the
anterior chamber to the intra-Tenon's space. The hollow shaft is
then withdrawn from the eye.
[0158] Referring to FIGS. 8 and 9, which show an intraocular shunt
placed into the eye such that the shunt forms a passage for fluid
drainage from the anterior chamber to the intra-Tenon's space. To
place the shunt within the eye, a surgical intervention to implant
the shunt is preformed that involves inserting into the eye 102 a
deployment device 100 that holds an intraocular shunt 101, and
deploying at least a portion of the shunt 101 within intra-Tenon's
space 108, within subconjunctival space 109 beneath the conjunctiva
110. In certain embodiments, a hollow shaft 106 of a deployment
device 100 holding the shunt 101 enters the eye 102 through the
cornea 103 (ab interno approach). The shaft 106 is advanced across
the anterior chamber 104 (as depicted by the broken line) in what
is referred to as a transpupil implant insertion. The shaft 106 is
advanced through the sclera 105 until a distal portion of the shaft
106 is in proximity to Tenon's capsule 107. After piercing the
sclera 105 with the hollow shaft 106 of the deployment device 100,
resistance to advancement of the shaft 106 encountered by an
operator of the deployment device 100 informs the operator that the
shaft 106 has contacted Tenon's capsule 107 and is thus in
proximity to Tenon's capsule 107.
[0159] Numerous techniques may be employed to ensure that after
piercing the sclera 105, the hollow shaft 106 does not pierce
Tenon's capsule 107. In certain embodiments, some methods involve
the use of a hollow shaft 106, in which a portion of the hollow
shaft extends linearly along a longitudinal axis and at least one
other portion of the shaft extends off the longitudinal axis. For
example, the hollow shaft 106 may have a bend in the distal portion
of the shaft, a U-shape, or an arcuate or V-shape in at least a
portion of the shaft. Examples of such hollow shafts 106 suitable
for use with some methods include but are not limited to the hollow
shafts 106 depicted in FIGS. 6A-6C. In embodiments in which the
hollow shaft 106 has a bend at a distal portion of the shaft,
intra-Tenon's shunt placement can be achieved by using the bent
distal portion of the shaft 106 to push Tenon's capsule 107 away
from the sclera 105 without penetrating Tenon's capsule 107. In
these embodiments, the tip of the distal end of the shaft 106 does
not contact Tenon's capsule 107.
[0160] In other embodiments, a straight hollow shaft 106 having a
beveled tip is employed. The angle of the beveled tip of the hollow
shaft is configured such that after piercing the sclera 105, the
hollow shaft 106 does not pierce Tenon's capsule 107. In these
embodiments, the shaft 106 is inserted into the eye 102 and through
the sclera 105 at an angle such that the bevel of the tip is
parallel to Tenon's capsule 107, thereby pushing Tenon's capsule
107 away from the sclera 105, rather than penetrating Tenon's
capsule 107, and allowing for deployment of a distal portion of the
shunt 101 into the intra-Tenon's space 108.
[0161] Once a distal portion of the hollow shaft 106 is within the
intra-Tenon's space 108, at least a portion of the device is
rotated, thereby reducing the friction between the portion of the
device that is in contact with the scleral tissue and the scleral
tissue itself. Reduction in friction allows for deployment of the
shunt from the device and then removal of the device from the eye
without disturbing the tissue of the eye. After rotating the
device, the shunt 101 is then deployed from the shaft 106 of the
deployment device 100, producing a conduit between the anterior
chamber 104 and the intra-Tenon's space 108 to allow aqueous humor
to drain from the anterior chamber 104 (See FIGS. 8 and 9).
[0162] In another embodiment, some methods further involves
injecting an aqueous solution into the eye below Tenon's capsule in
order to balloon the capsule away from the sclera. The increase in
intra-Tenon's space caused by the ballooning of Tenon's capsule is
helpful for positioning of the outlet of the shunt in the
intra-Tenon's space. The solution is injected prior to the shaft
piercing the sclera and entering the intra-Tenon's space. Suitable
aqueous solutions include but are not limited to Dulbecco's
Phosphate Buffered Saline (DPBS), Hank's Balanced Salt Solution
(HBSS), Phosphate-Buffered Saline (PBS), Earle's Balanced Salt
Solution (EBSS), or other balanced salt solutions known in the art.
In some embodiments, some methods involve injecting a viscoelastic
fluid into the eye. Preferably, some methods are conducted without
the use of a viscoelastic fluid. Some methods can be conducted
using any shunt deployment device known in the art. Examples of
deployment devices that are suitable for use with some methods
include but are not limited to the devices described in U.S. Pat.
No. 6,007,511, U.S. Pat. No. 6,544,249, and U.S. Pat. Pub. No.
US2008/0108933, the contents of each of which are hereby
incorporated by reference in their entireties.
[0163] In certain embodiments, to ensure proper positioning and
functioning of the intraocular shunt, the depth of penetration
through the sclera is important when conducting some methods. In
one embodiment, the distal tip of the hollow shaft pierces the
sclera without coring, removing or causing major tissue distortion
of the surrounding eye tissue. The shunt is then deployed from the
shaft. Preferably, a distal portion of the hollow shaft (as opposed
to the distal tip) completely penetrates the sclera before the
shunt is deployed from the hollow shaft. In certain embodiments,
the hollow shaft is a flat bevel needle, such as a needle having a
triple-ground point. The tip bevel first pierces through the sclera
making a horizontal slit. In a preferred embodiment of some
methods, the needle is advanced even further such that the entire
flat bevel penetrates through the sclera, as shown in FIG. 10D, to
spread and open the tissue to a full circular diameter. The tip
bevel portion 190 and flat bevel portion 192 of a triple ground
needle point, and the configuration of the shunt 194 disposed in
the needle point, are exemplified as the gray shaded areas in FIGS.
10A-10C. Without intending to be bound by any theory, if the
scleral channel is not completely forced open by the flat bevel
portion of the needle, the material around the opening may not be
sufficiently stretched and a pinching of the implant in that zone
will likely occur, causing the shunt to fail. Full penetration of
the flat bevel through the sclera causes minor distortion and
trauma to the local area. However, this area ultimately surrounds
and conforms to the shunt once the shunt is deployed in the
eye.
[0164] FIG. 11A depicts an example of an intraocular shunt
implanted in an eye in accordance with some methods using a triple
ground need point with 100% penetration of the flat bevel in the
scleral channel. FIG. 11B depicts an example of a shunt implanted
in an eye in accordance with some methods using a triple ground
needle point with approximately 50% penetration of the flat bevel
in the scleral channel. As shown in FIG. 11B, the shunt is almost
completely pinched off as compared to the open shunt depicted in
FIG. 11A.
[0165] Some methods may be conducted using any commercially
available shunts, such as the Optonol Ex-PRESS mini Glaucoma shunt,
and the Solx DeepLight Gold Micro-Shunt. However, some methods are
preferably conducted using the intraocular shunts of some
embodiments, as described herein.
Intraocular Shunts
[0166] The present inventions also provide intraocular shunts that
are configured to form a drainage pathway from the anterior chamber
of the eye to the intra-Tenon's space. In particular, the
intraocular some embodiments of the shunt have a length that is
sufficient to form a drainage pathway from the anterior chamber of
the eye to the intra-Tenon's space. The length of the shunt is
important in achieving placement specifically in the intra-Tenon's
space. A shunt that is too long will extend beyond the
intra-Tenon's space and irritate the conjunctiva, which can cause
the filtration procedure to fail, as previously described. A shunt
that is too short will not provide sufficient access to drainage
pathways such as the episcleral lymphatic system or the
conjunctival lymphatic system.
[0167] Some embodiments of the shunt may be any length that allows
for drainage of aqueous humor from an anterior chamber of an eye to
the intra-tenon's space. Exemplary shunts range in length from
approximately 0.5 mm to approximately 20 mm or between
approximately 4 mm to approximately 16 mm, or any specific value
within said ranges. In certain embodiments, the length of the shunt
is between approximately 6 to 8 mm, or any specific value within
said range, e.g., 6.0 mm, 6.1 mm, 6.2 mm, 6.3 mm, 6.4 mm, 6.5 mm,
6.6 mm, 6.7 mm, 6.8 mm, 6.9 mm, 7 mm, 7.1 mm, 7.2 mm, 7.3 mm, 7.4
mm, 7.5 mm, 7.6 mm, 7.7 mm, 7.8 mm. 7.9 mm, or 8.0 mm.
[0168] The intraocular some embodiments of the shunt are
particularly suitable for use in an ab interno glaucoma filtration
procedure. Commercially available shunts that are currently used in
ab interno filtration procedures are typically made of a hard,
inflexible material such as gold, polymer, titanium, or stainless
steel, and cause substantial irritation of the eye tissue,
resulting in ocular inflammation such as subconjunctival blebbing
or endophthalmitis. In contrast, the intraocular some embodiments
of the shunt are flexible, and have an elasticity modulus that is
substantially identical to the elasticity modulus of the
surrounding tissue in the implant site. As such, the intraocular
some embodiments of the shunt are easily bendable, do not erode or
cause a tissue reaction, and do not migrate once implanted. Thus,
when implanted in the eye using an ab interno procedure, such as
the methods described herein, the intraocular some embodiments of
the shunt do not induce substantial ocular inflammation such as
subconjunctival blebbing or endophthalmitis. Additional exemplary
features of the intraocular some embodiments of the shunt are
discussed in further detail below.
Tissue Compatible Shunts
[0169] In certain aspects, some embodiments generally provide
shunts composed of a material that has an elasticity modulus that
is compatible with an elasticity modulus of tissue surrounding the
shunt (e.g., tissue surrounding the suprachoroidal space). In this
manner, some embodiments of the shunt are flexibility matched with
the surrounding tissue, and thus will remain in place after
implantation without the need for any type of anchor that interacts
with the surrounding tissue. Consequently, some embodiments of the
shunt will maintain fluid flow away for an anterior chamber of the
eye after implantation without causing irritation or inflammation
to the tissue surrounding the eye.
[0170] Elastic modulus, or modulus of elasticity, is a mathematical
description of an object or substance's tendency to be deformed
elastically when a force is applied to it. The elastic modulus of
an object is defined as the slope of its stress-strain curve in the
elastic deformation region:
.lamda. = def Stress Strain ##EQU00001##
where lambda (.lamda.) is the elastic modulus; stress is the force
causing the deformation divided by the area to which the force is
applied; and strain is the ratio of the change caused by the stress
to the original state of the object. The elasticity modulus may
also be known as Young's modulus (E), which describes tensile
elasticity, or the tendency of an object to deform along an axis
when opposing forces are applied along that axis. Young's modulus
is defined as the ratio of tensile stress to tensile strain. For
further description regarding elasticity modulus and Young's
modulus, see for example Gere (Mechanics of Materials, 6th Edition,
2004, Thomson), the content of which is incorporated by reference
herein in its entirety.
[0171] The elasticity modulus of any tissue can be determined by
one of skill in the art. See for example Samani et al. (Phys. Med.
Biol. 48:2183, 2003); Erkamp et al. (Measuring The Elastic Modulus
Of Small Tissue Samples, Biomedical Engineering Department and
Electrical Engineering and Computer Science Department University
of Michigan Ann Arbor, Mich. 48109-2125; and Institute of
Mathematical Problems in Biology Russian Academy of Sciences,
Pushchino, Moscow Region 142292 Russia); Chen et al. (IEEE Trans.
Ultrason. Ferroelec. Freq. Control 43:191-194, 1996); Hall, (In
1996 Ultrasonics Symposium Proc., pp. 1193-1196, IEEE Cat. No.
96CH35993, IEEE, New York, 1996); and Parker (Ultrasound Med. Biol.
16:241-246, 1990), each of which provides methods of determining
the elasticity modulus of body tissues. The content of each of
these is incorporated by reference herein in its entirety.
[0172] The elasticity modulus of tissues of different organs is
known in the art. For example, Pierscionek et al. (Br J Ophthalmol,
91:801-803, 2007) and Friberg (Experimental Eye Research,
473:429-436, 1988) show the elasticity modulus of the cornea and
the sclera of the eye. The content of each of these references is
incorporated by reference herein in its entirety. Chen, Hall, and
Parker show the elasticity modulus of different muscles and the
liver. Erkamp shows the elasticity modulus of the kidney.
[0173] Some embodiments of the shunt are composed of a material
that is compatible with an elasticity modulus of tissue surrounding
the shunt. In certain embodiments, the material has an elasticity
modulus that is substantially identical to the elasticity modulus
of the tissue surrounding the shunt. In other embodiments, the
material has an elasticity modulus that is greater than the
elasticity modulus of the tissue surrounding the shunt. Exemplary
materials includes biocompatible polymers, such as polycarbonate,
polyethylene, polyethylene terephthalate, polyimide, polystyrene,
polypropylene, poly(styrene-b-isobutylene-b-styrene), or silicone
rubber.
[0174] In particular embodiments, some embodiments of the shunt are
composed of a material that has an elasticity modulus that is
compatible with the elasticity modulus of tissue in the eye,
particularly scleral tissue. In certain embodiments, compatible
materials are those materials that are softer than scleral tissue
or marginally harder than scleral tissue, yet soft enough to
prohibit shunt migration. The elasticity modulus for anterior
scleral tissue is approximately 2.9.+-.1.4.times.106 N/m2, and
1.8.+-.1.1.times.106 N/m2 for posterior scleral tissue. See Friberg
(Experimental Eye Research, 473:429-436, 1988). An exemplary
material is cross linked gelatin derived from Bovine or Porcine
Collagen.
[0175] Some embodiments encompasses shunts of different shapes and
different dimensions, and some embodiments of the shunt may be any
shape or any dimension that may be accommodated by the eye. In
certain embodiments, the intraocular shunt is of a cylindrical
shape and has an outside cylindrical wall and a hollow interior.
The shunt may have an inside diameter from approximately 10 .mu.m
to approximately 250 .mu.m, an outside diameter from diameter from
approximately 100 .mu.m to approximately 450 .mu.m, such as
approximately 190 .mu.m to approximately 300 .mu.m, and a length
from approximately 0.5 mm to approximately 20 mm, such as from
approximately 2 mm to approximately 10 mm.
Shunts Reactive to Pressure
[0176] In other aspects, some embodiments generally provide shunts
in which a portion of the shunt is composed of a flexible material
that is reactive to pressure, i.e., the diameter of the flexible
portion of the shunt fluctuates depending upon the pressures
exerted on that portion of the shunt. FIG. 12 provides a schematic
of a shunt 223 having a flexible portion 251. In this figure, the
flexible portion 251 is shown in the middle of the shunt 223.
However, the flexible portion 251 may be located in any portion of
the shunt, such as the proximal or distal portion of the shunt. In
certain embodiments, the entire shunt is composed of the flexible
material, and thus the entire shunt is flexible and reactive to
pressure.
[0177] The flexible portion 251 of the shunt 223 acts as a valve
that regulates fluid flow through the shunt. The human eye produces
aqueous humor at a rate of about 2 .mu.l/min for approximately 3
ml/day. The entire aqueous volume is about 0.25 ml. When the
pressure in the anterior chamber falls after surgery to about 7-8
mmHg, it is assumed the majority of the aqueous humor is exiting
the eye through the implant since venous backpressure prevents any
significant outflow through normal drainage structures (e.g., the
trabecular meshwork).
[0178] After implantation, intraocular shunts have pressure exerted
upon them by tissues surrounding the shunt (e.g., scleral tissue
such as the sclera channel and the sclera exit) and pressure
exerted upon them by aqueous humor flowing through the shunt. The
flow through the shunt, and thus the pressure exerted by the fluid
on the shunt, is calculated by the equation:
.PHI. = V T = .nu..pi. R 2 = .pi. R 4 8 .eta. ( - .DELTA. P .DELTA.
x ) = .pi. R 4 8 .eta. .DELTA. P L ##EQU00002##
where .PHI. is the volumetric flow rate; V is a volume of the
liquid poured (cubic meters); t is the time (seconds); .nu. is mean
fluid velocity along the length of the tube (meters/second); x is a
distance in direction of flow (meters); R is the internal radius of
the tube (meters); .DELTA.P is the pressure difference between the
two ends (pascals); .eta. is the dynamic fluid viscosity
(pascal-second (Pas)); and L is the total length of the tube in the
x direction (meters).
[0179] FIG. 13A provides a schematic of a shunt 226 implanted into
an eye for regulation of fluid flow from the anterior chamber of
the eye to an area of lower pressure (e.g., the intra-Tenon's
space, the subconjunctival space, the episcleral vein, the
suprachoroidal space, or Schlemm's canal). In certain embodiments,
the area of lower pressure is the subarachnoid space. The shunt is
implanted such that a proximal end 227 of the shunt 226 resides in
the anterior chamber 228 of the eye, and a distal end 229 of the
shunt 226 resides outside of the anterior chamber to conduct
aqueous humor from the anterior chamber to an area of lower
pressure. A flexible portion 230 of the shunt 226 spans at least a
portion of the sclera of the eye. As shown in FIG. 13A, the
flexible portion spans an entire length of the sclera 221.
[0180] When the pressure exerted on the flexible portion 230 of the
shunt 226 by sclera 231 (vertical arrows) is greater than the
pressure exerted on the flexible portion 230 of the shunt 226 by
the fluid flowing through the shunt (horizontal arrow), the
flexible portion 230 decreases in diameter, restricting flow
through the shunt 226 (FIG. 13B). The restricted flow results in
aqueous humor leaving the anterior chamber 228 at a reduced
rate.
[0181] When the pressure exerted on the flexible portion 230 of the
shunt 226 by the fluid flowing through the shunt (horizontal arrow)
is greater than the pressure exerted on the flexible portion 230 of
the shunt 226 by the sclera 231 (vertical arrows), the flexible
portion 230 increases in diameter, increasing flow through the
shunt 226 (FIG. 13C). The increased flow results in aqueous humor
leaving the anterior chamber 228 at an increased rate.
[0182] Some embodiments encompasses shunts of different shapes and
different dimensions, and some embodiments of the shunt may be any
shape or any dimension that may be accommodated by the eye. In
certain embodiments, the intraocular shunt is of a cylindrical
shape and has an outside cylindrical wall and a hollow interior.
The shunt may have an inside diameter from approximately 10 .mu.m
to approximately 250 .mu.m, an outside diameter from diameter from
approximately 100 .mu.m to approximately 450 .mu.m, such as
approximately 190 .mu.m to approximately 300 .mu.m, and a length
from approximately 0.5 mm to approximately 20 mm, such as from
approximately 2 mm to approximately 10 mm.
[0183] In a particular embodiments, the shunt has a length of about
6 mm and an inner diameter of about 64 .mu.m. With these
dimensions, the pressure difference between the proximal end of the
shunt that resides in the anterior chamber and the distal end of
the shunt that resides outside the anterior chamber is about 4.3
mmHg. Such dimensions thus allow the implant to act as a controlled
valve and protect the integrity of the anterior chamber.
[0184] It will be appreciated that different dimensioned implants
may be used. For example, shunts that range in length from about
0.5 mm to about 20 mm, such as from about 2 mm to about 10 mm, and
have a range in inner diameter from about 10 .mu.m to about 100
.mu.m allow for pressure control from approximately 0.5 mmHg to
approximately 20 mmHg.
[0185] The material of the flexible portion and the thickness of
the wall of the flexible portion will determine how reactive the
flexible portion is to the pressures exerted upon it by the
surrounding tissue and the fluid flowing through the shunt.
Generally, with a certain material, the thicker the flexible
portion, the less responsive the portion will be to pressure. In
certain embodiments, the flexible portion is a gelatin or other
similar material, and the thickness of the gelatin material forming
the wall of the flexible portion ranges from about 10 .mu.m thick
to about 100 .mu.m thick.
[0186] In a certain embodiment, the gelatin used for making the
flexible portion is known as gelatin Type B from bovine skin. An
exemplary gelatin is PB Leiner gelatin from bovine skin, Type B,
225 Bloom, USP. Another material that may be used in the making of
the flexible portion is a gelatin Type A from porcine skin, also
available from Sigma Chemical. Such gelatin is available from Sigma
Chemical Company of St. Louis, Mo. under Code G-9382. Still other
suitable gelatins include bovine bone gelatin, porcine bone gelatin
and human-derived gelatins. In addition to gelatins, the flexible
portion may be made of hydroxypropyl methylcellulose (HPMC),
collagen, polylactic acid, polylglycolic acid, hyaluronic acid and
glycosaminoglycans.
[0187] In certain embodiments, the gelatin is cross-linked.
Cross-linking increases the inter- and intramolecular binding of
the gelatin substrate. Any method for cross-linking the gelatin may
be used. In a particular embodiment, the formed gelatin is treated
with a solution of a cross-linking agent such as, but not limited
to, glutaraldehyde. Other suitable compounds for cross-linking
include 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC).
Cross-linking by radiation, such as gamma or electron beam (e-beam)
may be alternatively employed.
[0188] In one embodiment, the gelatin is contacted with a solution
of approximately 25% glutaraldehyde for a selected period of time.
One suitable form of glutaraldehyde is a grade 1G5882
glutaraldehyde available from Sigma Aldridge Company of Germany,
although other glutaraldehyde solutions may also be used. The pH of
the glutaraldehyde solution should be in the range of 7 to 7.8 and,
more particularly, 7.35-7.44 and typically approximately
7.4+/-0.01. If necessary, the pH may be adjusted by adding a
suitable amount of a base such as sodium hydroxide as needed.
[0189] Methods for forming the flexible portion of the shunt are
shown for example in Yu et al. (U.S. Pat. Pub. No. 2008/0108933),
the content of which is incorporated by reference herein in its
entirety. In an exemplary protocol, the flexible portion may be
made by dipping a core or substrate such as a wire of a suitable
diameter in a solution of gelatin. The gelatin solution is
typically prepared by dissolving a gelatin powder in de-ionized
water or sterile water for injection and placing the dissolved
gelatin in a water bath at a temperature of approximately
55.degree. C. with thorough mixing to ensure complete dissolution
of the gelatin. In one embodiment, the ratio of solid gelatin to
water is approximately 10% to 50% gelatin by weight to 50% to 90%
by weight of water. In an embodiment, the gelatin solution includes
approximately 40% by weight, gelatin dissolved in water. The
resulting gelatin solution should be devoid of air bubbles and has
a viscosity that is between approximately 200-500 cp and more
particularly between approximately 260 and 410 cp (centipoise).
[0190] Once the gelatin solution has been prepared, in accordance
with the method described above, supporting structures such as
wires having a selected diameter are dipped into the solution to
form the flexible portion. Stainless steel wires coated with a
biocompatible, lubricious material such as polytetrafluoroethylene
(Teflon) are preferred.
[0191] Typically, the wires are gently lowered into a container of
the gelatin solution and then slowly withdrawn. The rate of
movement is selected to control the thickness of the coat. In
addition, it is preferred that the tube be removed at a constant
rate in order to provide the desired coating. To ensure that the
gelatin is spread evenly over the surface of the wire, in one
embodiment, the wires may be rotated in a stream of cool air which
helps to set the gelatin solution and affix film onto the wire.
Dipping and withdrawing the wire supports may be repeated several
times to further ensure even coating of the gelatin. Once the wires
have been sufficiently coated with gelatin, the resulting gelatin
films on the wire may be dried at room temperature for at least 1
hour, and more preferably, approximately 10 to 24 hours. Apparatus
for forming gelatin tubes are described in Yu et al. (U.S. Pat.
Pub. No. 2008/0108933).
[0192] Once dried, the formed flexible portions may be treated with
a cross-linking agent. In one embodiment, the formed flexible
portion may be cross-linked by dipping the wire (with film thereon)
into the 25% glutaraldehyde solution, at pH of approximately
7.0-7.8 and more preferably approximately 7.35-7.44 at room
temperature for at least 4 hours and preferably between
approximately 10 to 36 hours, depending on the degree of
cross-linking desired. In one embodiment, the formed flexible
portion is contacted with a cross-linking agent such as
gluteraldehyde for at least approximately 16 hours. Cross-linking
can also be accelerated when it is performed a high temperatures.
It is believed that the degree of cross-linking is proportional to
the bioabsorption time of the shunt once implanted. In general, the
more cross-linking, the longer the survival of the shunt in the
body.
[0193] The residual glutaraldehyde or other cross-linking agent is
removed from the formed flexible portion by soaking the tubes in a
volume of sterile water for injection. The water may optionally be
replaced at regular intervals, circulated or re-circulated to
accelerate diffusion of the unbound glutaraldehyde from the tube.
The tubes are washed for a period of a few hours to a period of a
few months with the ideal time being 3-14 days. The now
cross-linked gelatin tubes may then be dried (cured) at ambient
temperature for a selected period of time. It has been observed
that a drying period of approximately 48-96 hours and more
typically 3 days (i.e., 72 hours) may be preferred for the
formation of the cross-linked gelatin tubes.
[0194] Where a cross-linking agent is used, it may be desirable to
include a quenching agent in the method of making the flexible
portion. Quenching agents remove unbound molecules of the
cross-linking agent from the formed flexible portion. In certain
cases, removing the cross-linking agent may reduce the potential
toxicity to a patient if too much of the cross-linking agent is
released from the flexible portion. In certain embodiments, the
formed flexible portion is contacted with the quenching agent after
the cross-linking treatment and, may be included with the
washing/rinsing solution. Examples of quenching agents include
glycine or sodium borohydride.
[0195] The formed flexible portion may be further coated or
impregnated with biologics and/or pharmaceuticals, as discussed
herein.
[0196] After the requisite drying period, the formed and
cross-linked flexible portion is removed from the underlying
supports or wires. In one embodiment, wire tubes may be cut at two
ends and the formed gelatin flexible portion slowly removed from
the wire support. In another embodiment, wires with gelatin film
thereon, may be pushed off using a plunger or tube to remove the
formed gelatin flexible portion.
Multi-Port Shunts
[0197] Other aspects of some embodiments generally provide
multi-port shunts. Such shunts reduce probability of the shunt
clogging after implantation because fluid can enter or exit the
shunt even if one or more ports of the shunt become clogged with
particulate. In certain embodiments, the shunt includes a hollow
body defining a flow path and more than two ports, in which the
body is configured such that a proximal portion receives fluid from
the anterior chamber of an eye and a distal portion directs the
fluid to a location of lower pressure with respect to the anterior
chamber. Exemplary areas of lower pressure include intra-Tenon's
space, the subconjunctival space, the episcleral vein, the
suprachoroidal space, Schlemm's canal, or drainage structures
associated with the intra-scleral space. Another exemplary area of
lower pressure to which fluid may be drained is the subarachnoid
space.
[0198] The shunt may have many different configurations. FIG. 14A
shows an embodiment of a shunt 232 in which the proximal portion of
the shunt (i.e., the portion disposed within the anterior chamber
of the eye) includes more than one port (designated as numbers 233a
to 233e) and the distal portion of the shunt (i.e., the portion
that is located in the intra-Tenon's space) includes a single port
234. FIG. 14B shows another embodiment of a shunt 232 in which the
proximal portion includes a single port 233 and the distal portion
includes more than one port (designated as numbers 234a to 234e).
FIG. 14C shows another embodiment of a shunt 232 in which the
proximal portions include more than one port (designated as numbers
233a to 233e) and the distal portions include more than one port
(designated as numbers 234a to 234e). While FIGS. 14A-14C show
shunts that have five ports at the proximal portion, distal
portion, or both, those shunts are only exemplary embodiments. The
ports may be located along any portion of the shunt, and some
embodiments of the shunt include all shunts having more than two
ports. For example, some embodiments of the shunt may include at
least three ports, at least four ports, at least five ports, at
least 10 ports, at least 15 ports, or at least 20 ports.
[0199] The ports may be positioned in various different
orientations and along various different portions of the shunt. In
certain embodiments, at least one of the ports is oriented at an
angle to the length of the body. In certain embodiments, at least
one of the ports is oriented 90.degree. to the length of the body.
See for example FIG. 14A, which depicts ports 233a, 233b, 233d, and
233e as being oriented at a 90.degree. angle to port 233c.
[0200] The ports may have the same or different inner diameters. In
certain embodiments, at least one of the ports has an inner
diameter that is different from the inner diameters of the other
ports. FIGS. 15A-15B show embodiments of a shunt 232 having
multiple ports (233a and 233b) at a proximal end and a single port
234 at a distal end. FIG. 15A shows that port 233b has an inner
diameter that is different from the inner diameters of ports 233a
and 234. In this figure, the inner diameter of port 233b is less
than the inner diameter of ports 233a and 234. An exemplary inner
diameter of port 233b is from about 20 .mu.m to about 40 .mu.m,
particularly about 30 .mu.m. In other embodiments, the inner
diameter of port 33b is greater than the inner diameter of ports
233a and 234. See for example FIG. 15B.
[0201] Some embodiments encompasses shunts of different shapes and
different dimensions, and some embodiments of the shunt may be any
shape or any dimension that may be accommodated by the eye. In
certain embodiments, the intraocular shunt is of a cylindrical
shape and has an outside cylindrical wall and a hollow interior.
The shunt may have an inside diameter from approximately 10 .mu.m
to approximately 250 .mu.m, an outside diameter from approximately
190 .mu.m to approximately 300 .mu.m, and a length from
approximately 0.5 mm to approximately 20 mm. Some embodiments of
the shunt may be made from any biocompatible material. An exemplary
material is gelatin. Methods of making shunts composed of gelatin
are described above.
Shunts with Overflow Ports
[0202] Other aspects of some embodiments generally provide shunts
with overflow ports. Those shunts are configured such that the
overflow port remains partially or completely closed until there is
a pressure build-up within the shunt sufficient to force open the
overflow port. Such pressure build-up typically results from
particulate partially or fully clogging an entry or an exit port of
the shunt. Such shunts reduce probability of the shunt clogging
after implantation because fluid can enter or exit the shunt by the
overflow port even if one port of the shunt becomes clogged with
particulate.
[0203] In certain embodiments, the shunt includes a hollow body
defining an inlet configured to receive fluid from an anterior
chamber of an eye and an outlet configured to direct the fluid to
the intra-Tenon's or intrascleral space, or other areas of lower
pressure disclosed herein, the body further including at least one
slit. The slit may be located at any place along the body of the
shunt. FIG. 16A shows a shunt 235 having an inlet 236, an outlet
237, and a slit 238 located in proximity to the inlet 236. FIG. 16B
shows a shunt 235 having an inlet 236, an outlet 237, and a slit
239 located in proximity to the outlet 237. FIG. 16C shows a shunt
235 having an inlet 236, an outlet 237, a slit 238 located in
proximity to the inlet 236, and a slit 239 located in proximity to
the outlet 237.
[0204] While FIGS. 16A-16B show shunts have only a single overflow
port at the proximal portion, the distal portion, or both the
proximal and distal portions, those shunts are only exemplary
embodiments. The overflow port(s) may be located along any portion
of the shunt, and some embodiments of the shunt include shunts
having more than one overflow port. In certain embodiments, some
embodiments of the shunt include more than one overflow port at the
proximal portion, the distal portion, or both. For example, FIG. 17
shows a shunt 240 having an inlet 241, an outlet 242, and slits
243a and 243b located in proximity to the inlet 241. Some
embodiments of the shunt may include at least two overflow ports,
at least three overflow ports, at least four overflow ports, at
least five overflow ports, at least 10 overflow ports, at least 15
overflow ports, or at least 20 overflow ports. In certain
embodiments, some embodiments of the shunt include two slits that
overlap and are oriented at 90.degree. to each other, thereby
forming a cross.
[0205] In certain embodiments, the slit may be at the proximal or
the distal end of the shunt, producing a split in the proximal or
the distal end of the implant. FIG. 18 shows an embodiment of a
shunt 244 having an inlet 245, outlet 246, and a slit 247 that is
located at the proximal end of the shunt, producing a split in the
inlet 245 of the shunt.
[0206] In certain embodiments, the slit has a width that is
substantially the same or less than an inner diameter of the inlet.
In other embodiments, the slit has a width that is substantially
the same or less than an inner diameter of the outlet. In certain
embodiments, the slit has a length that ranges from about 0.05 mm
to about 2 mm, and a width that ranges from about 10 .mu.m to about
200 .mu.m. Generally, the slit does not direct the fluid unless the
outlet is obstructed. However, the shunt may be configured such
that the slit does direct at least some of the fluid even if the
inlet or outlet is not obstructed.
[0207] Some embodiments encompasses shunts of different shapes and
different dimensions, and some embodiments of the shunt may be any
shape or any dimension that may be accommodated by the eye. In
certain embodiments, the intraocular shunt is of a cylindrical
shape and has an outside cylindrical wall and a hollow interior.
The shunt may have an inside diameter from approximately 10 .mu.m
to approximately 250 .mu.m, an outside diameter from diameter from
approximately 100 .mu.m to approximately 450 .mu.m, such as
approximately 190 .mu.m to approximately 300 .mu.m, and a length
from approximately 0.5 mm to approximately 20 mm, such as from
approximately 2 mm to approximately 10 mm. Some embodiments of the
shunt may be made from any biocompatible material. An exemplary
material is gelatin. Methods of making shunts composed of gelatin
are described above.
Shunts Having a Variable Inner Diameter
[0208] In other aspects, some embodiments generally provide a shunt
having a variable inner diameter. In particular embodiments, the
diameter increases from inlet to outlet of the shunt. By having a
variable inner diameter that increases from inlet to outlet, a
pressure gradient is produced and particulate that may otherwise
clog the inlet of the shunt is forced through the inlet due to the
pressure gradient. Further, the particulate will flow out of the
shunt because the diameter only increases after the inlet.
[0209] FIGS. 19A-19B show embodiments of a shunt 248 having an
inlet 249 configured to receive fluid from an anterior chamber of
an eye and an outlet 250 configured to direct the fluid to a
location of lower pressure with respect to the anterior chamber, in
which the body further includes a variable inner diameter that
increases along the length of the body from the inlet 249 to the
outlet 250. In certain embodiments, the inner diameter continuously
increases along the length of the body, for example as shown in
FIG. 19A. In other embodiments, the inner diameter remains constant
along portions of the length of the body, as shown in FIG. 19B.
[0210] In exemplary embodiments, the inner diameter may range in
size from about 10 .mu.m to about 200 .mu.m, and the inner diameter
at the outlet may range in size from about 15 .mu.m to about 300
.mu.m. Some embodiments encompasses shunts of different shapes and
different dimensions, and some embodiments of the shunt may be any
shape or any dimension that may be accommodated by the eye. In
certain embodiments, the intraocular shunt is of a cylindrical
shape and has an outside cylindrical wall and a hollow interior.
The shunt may have an inside diameter from approximately 10 .mu.m
to approximately 250 .mu.m, an outside diameter from diameter from
approximately 100 .mu.m to approximately 450 .mu.m, such as
approximately 190 .mu.m to approximately 300 .mu.m, and a length
from approximately 0.5 mm to approximately 20 mm, such as from
approximately 2 mm to approximately 10 mm. Some embodiments of the
shunt may be made from any biocompatible material. An exemplary
material is gelatin. Methods of making shunts composed of gelatin
are described above.
Shunts Having Pronged Ends
[0211] In other aspects, some embodiments generally provide shunts
for facilitating conduction of fluid flow away from an organ, the
shunt including a body, in which at least one end of the shunt is
shaped to have a plurality of prongs. Such shunts reduce
probability of the shunt clogging after implantation because fluid
can enter or exit the shunt by any space between the prongs even if
one portion of the shunt becomes clogged with particulate.
[0212] FIGS. 20A-20D show embodiments of a shunt 252 in which at
least one end of the shunt 252 includes a plurality of prongs
253a-d. FIGS. 20A-20D show embodiments in which both a proximal end
and a distal end of the shunt are shaped to have the plurality of
prongs. However, numerous different configurations are envisioned.
For example, in certain embodiments, only the proximal end of the
shunt is shaped to have the plurality of prongs. In other
embodiments, only the distal end of the shunt is shaped to have the
plurality of prongs.
[0213] Prongs 253a-d can have any shape (i.e., width, length,
height). FIGS. 20A-20B show prongs 253a-d as straight prongs. In
this embodiment, the spacing between the prongs 253a-d is the same.
In another embodiment shown in FIGS. 20C-20D, prongs 253a-d are
tapered. In this embodiment, the spacing between the prongs
increases toward a proximal and/or distal end of the shunt 252.
[0214] FIGS. 20A-20D show embodiments that include four prongs.
However, some embodiments of the shunt may accommodate any number
of prongs, such as two prongs, three prongs, four prongs, five
prongs, six prongs, seven prongs, eight prongs, nine prongs, ten
prongs, etc. The number of prongs chosen will depend on the desired
flow characteristics of the shunt.
[0215] Some embodiments encompass shunts of different shapes and
different dimensions, and some embodiments of the shunt may be any
shape or any dimension that may be accommodated by the eye. In
certain embodiments, the intraocular shunt is of a cylindrical
shape and has an outside cylindrical wall and a hollow interior.
The shunt may have an inside diameter from approximately 10 .mu.m
to approximately 250 .mu.m, an outside diameter from approximately
100 .mu.m to approximately 450 .mu.m, and a length from
approximately 2 mm to approximately 10 mm. Some embodiments of the
shunt may be made from any biocompatible material. An exemplary
material is gelatin. Methods of making shunts composed of gelatin
are described above.
Shunts Having a Longitudinal Slit
[0216] In other aspects, some embodiments generally provide a shunt
for draining fluid from an anterior chamber of an eye that includes
a hollow body defining an inlet configured to receive fluid from an
anterior chamber of the eye and an outlet configured to direct the
fluid to a location of lower pressure with respect to the anterior
chamber; the shunt being configured such that at least one end of
the shunt includes a longitudinal slit. Such shunts reduce
probability of the shunt clogging after implantation because the
end(s) of the shunt can more easily pass particulate which would
generally clog a shunt lacking the slits.
[0217] FIGS. 21A-21D show embodiments of a shunt 254 in which at
least one end of the shunt 254 includes a longitudinal slit 255
that produces a top portion 256a and a bottom portion 256b in a
proximal and/or distal end of the shunt 254. FIGS. 21A-21D show an
embodiment in which both a proximal end and a distal end include a
longitudinal slit 255 that produces a top portion 256a and a bottom
portion 256b in both ends of the shunt 254. However, numerous
different configurations are envisioned. For example, in certain
embodiments, only the proximal end of the shunt includes
longitudinal slit 255. In other embodiments, only the distal end of
the shunt includes longitudinal slit 255.
[0218] Longitudinal slit 255 can have any shape (i.e., width,
length, height). FIGS. 21A-21B show a longitudinal slit 255 that is
straight such that the space between the top portion 256a and the
bottom portion 256b remains the same along the length of the slit
255. In another embodiment shown in FIGS. 21C-21D, longitudinal
slit 255 is tapered. In this embodiment, the space between the top
portion 245a and the bottom portion 256b increases toward a
proximal and/or distal end of the shunt 254.
[0219] Some embodiments encompass shunts of different shapes and
different dimensions, and some embodiments of the shunt may be any
shape or any dimension that may be accommodated by the eye. In
certain embodiments, the intraocular shunt is of a cylindrical
shape and has an outside cylindrical wall and a hollow interior.
The shunt may have an inside diameter from approximately 10 .mu.m
to approximately 250 .mu.m, an outside diameter from approximately
100 .mu.m to approximately 450 .mu.m, and a length from
approximately 2 mm to approximately 10 mm. Some embodiments of the
shunt may be made from any biocompatible material. An exemplary
material is gelatin. Methods of making shunts composed of gelatin
are described above.
Pharmaceutical Agents
[0220] In certain embodiments, some embodiments of the shunt may be
coated or impregnated with at least one pharmaceutical and/or
biological agent or a combination thereof. The pharmaceutical
and/or biological agent may coat or impregnate an entire exterior
of the shunt, an entire interior of the shunt, or both.
Alternatively, the pharmaceutical or biological agent may coat
and/or impregnate a portion of an exterior of the shunt, a portion
of an interior of the shunt, or both. Methods of coating and/or
impregnating an intraocular shunt with a pharmaceutical and/or
biological agent are known in the art. See for example, Darouiche
(U.S. Pat. Nos. 7,790,183; 6,719,991; 6,558,686; 6,162,487;
5,902,283; 5,853,745; and 5,624,704) and Yu et al. (U.S. Pat. Pub.
No. 2008/0108933). The content of each of these references is
incorporated by reference herein its entirety.
[0221] In certain embodiments, the exterior portion of the shunt
that resides in the anterior chamber after implantation (e.g.,
about 1 mm of the proximal end of the shunt) is coated and/or
impregnated with the pharmaceutical or biological agent. In other
embodiments, the exterior of the shunt that resides in the scleral
tissue after implantation of the shunt is coated and/or impregnated
with the pharmaceutical or biological agent. In other embodiments,
the exterior portion of the shunt that resides in the area of lower
pressure, such as the intrascleral space, the intra-Tenon's space,
or the subconjunctival space, after implantation is coated and/or
impregnated with the pharmaceutical or biological agent. In
embodiments in which the pharmaceutical or biological agent coats
and/or impregnates the interior of the shunt, the agent may be
flushed through the shunt and into the area of lower pressure
(e.g., the intra-Tenon's space or the subconjunctival space).
[0222] Any pharmaceutical and/or biological agent or combination
thereof may be used with some embodiments of the shunt. The
pharmaceutical and/or biological agent may be released over a short
period of time (e.g., seconds) or may be released over longer
periods of time (e.g., days, weeks, months, or even years).
Exemplary agents include anti-mitotic pharmaceuticals such as
Mitomycin-C or 5-Fluorouracil, anti-VEGF (such as Lucintes,
Macugen, Avastin, VEGF or steroids).
[0223] Reference is now made to FIG. 22A which shows an embodiment
of a shunt deployment device 300 according to some embodiments. In
some embodiments, the device 300 may be used to re-open a partially
or completely closed anterior chamber angle and deploy an
intraocular shunt. While FIG. 22A shows a handheld manually
operated shunt deployment device, it will be appreciated that some
embodiments of the device may be coupled with robotic systems and
may be completely or partially automated. As shown in FIG. 22A
deployment device 300 includes a generally cylindrical body or
housing 301, however, the body shape of housing 301 could be other
than cylindrical. Housing 301 may have an ergonomical shape,
allowing for comfortable grasping by an operator. Housing 301 is
shown with optional grooves 302 to allow for easier gripping by a
surgeon.
[0224] FIG. 22B shows a cross sectional view of device 300. This
figure shows that housing 301 includes a proximal portion 301a and
a distal portion 301b. The distal portion 301b is movable within
proximal portion 301a. In this figure, spring mechanism 320
includes a spring 321 that controls movement of distal portion
301b. Spring mechanism 320 further includes a member 322 that acts
as a stopper and limits axial retraction of distal portion 301b
within proximal portion 301a. Spring mechanism 320 further includes
members 323 and 324 that run the length of spring 321. The ends of
members 323 and 324 include flanges 325 and 326 that project inward
from members 323 and 324. An end of distal portion 301b includes
flanges 327 and 328 that project outward from distal portion 301b.
Flanges 325 and 326 interact with flanges 327 and 328 to prevent
release of distal portion 301b from proximal portion 301a. The
flanges 325 and 326 and 327 and 328 hold the distal portion 301b in
an extended position until a compressive force acts upon distal
portion 301b, thereby causing distal portion 301b to partially
retract within proximal portion 301a.
[0225] Distal portion 301b includes a capsule 329 and a hollow
sleeve 330. Capsule 329 and sleeve 330 may be formed integrally or
may be separate components that are coupled or connected to each
other. The hollow sleeve 330 is configured for insertion into an
eye and to extend into an anterior chamber of an eye. FIG. 22B
shows distal portion 301b of housing 301 extended from proximal
portion 301a of housing 301. In this configuration, hollow shaft
304 (not shown in this figure) is completely disposed within sleeve
330. FIG. 22C shows distal portion 301b of housing 301 retracted
within proximal portion 301a of housing 301. Retraction of distal
portion 301b of housing 301 within proximal portion 301a of housing
301 exposes hollow shaft 304, which is discussed in greater detail
below.
[0226] The hollow shaft 304 may include a sharpened distal end.
With reference to FIG. 22D, the hollow shaft 304 may be flexible
and pre-bent to follow the scleral spur down along the sclera upon
extension of the hollow shaft 304 from the sleeve 330, which is
discussed in greater detail below. The material used for the hollow
shaft 304 may be any memory shape material, such as spring steel,
such that the hollow shaft 304 can easily transform from its bent
position to a straight cannula when housed within the sleeve
330.
[0227] A distal end of sleeve 330 may optionally include a
protrusion 331 (FIG. 22D). Protrusion 331 provides resistance
feedback to an operator as the operator is advancing the sleeve 330
through an anterior chamber of an eye. Further, protrusion 331 can
be of a shape and size that it is capable of re-opening a partially
or completely closed anterior chamber angle of an eye as an
operator is advancing the device 300 through an anterior chamber of
an eye. In a standard ab interno approach (see, for example, Yu et
al. U.S. Pat. No. 6,544,249 and U.S. Pat. Pub. No. 2008/0108933) a
deployment device holding a shunt enters an eye through a cornea.
The deployment device is advanced across the anterior chamber in
what is referred to as a transpupil implant insertion. The
deployment device is advanced to the sclera on the opposite side of
the eye from which the device entered the eye. With some
embodiments of the device, upon advancement of the device 300
across an anterior chamber of the eye, the protrusion 331 at the
distal end of the hollow sleeve 330 will contact the sclera,
providing resistance feedback to an operator that no further
advancement of the device 300 is necessary (see FIGS. 38A-38E).
This feedback also informs the operator that the device 300 is in
proper position for exposure of the hollow shaft 304, which will
advance through the sclera for deployment of an intraocular shunt.
The protrusion 331, provides adequate surface area at the distal
end of sleeve 330, thus preventing sleeve 330 from entering the
sclera.
[0228] Further, in some embodiments, the deployment device can be
advanced into the anterior chamber angle on the opposite side of
the eye from which the device entered the eye. With some
embodiments of the device, upon advancement of the device 300
across an anterior chamber of the eye, the protrusion 331 at the
distal end of the hollow sleeve 330 will contact a partially or
completely closed anterior chamber angle, and continued advancement
of the device 300 will result in the protrusion 331 re-opening the
partially or completely closed anterior chamber angle. Once
re-opened by the protrusion 131, the device 300 can be moved into
proper position for exposure of the hollow shaft 304, which will
advance through the sclera for deployment of an intraocular shunt.
The protrusion 331, provides adequate surface area at the distal
end of sleeve 330, thus preventing sleeve 330 from entering the
tissue of the eye that is blocking access the trabecular meshwork
(e.g., the iris).
[0229] In certain embodiments, protrusion 331 has a substantially
flat bottom portion and an angled top portion (FIG. 22E). In other
embodiments, protrusion 331 has a slightly tapered top and a
slightly tapered bottom with a rounded distal portion (FIGS.
23A-23C).
[0230] Referring back to FIG. 22E, the angle of the top portion is
substantially identical to an anterior chamber angle of an eye.
Such a shape of the protrusion ensures that some embodiments of the
device will also finds its way to fit, such as by conforming and
sliding, into the anterior chamber angle of the eye, the place for
proper deployment of an intraocular shunt. This is explained with
reference to FIGS. 24A to 24E. FIG. 24A shows device 300 in an
insertion configuration and inserted into an eye 340. In this
figure, protrusion 331 at the distal end of the sleeve 330 has been
advanced across the anterior chamber 341 to the sclera 342 on the
opposite side of the eye 340 from which the device entered the eye
340. FIG. 24A shows protrusion 331 fitted within the anterior
chamber angle 343 of the eye 340. If sleeve 330 enters the anterior
chamber 341 at too shallow an angle, i.e., the protrusion 331 hit
the sclera 342 above the anterior chamber angle 343, the angled top
portion of the protrusion 331 causes the sleeve 330 to slide down
the sclera 342 (direction of arrow) until the protrusion 331 is fit
within the anterior chamber angle 343 of the eye 340 (FIGS. 24B and
24C). The sleeve 330 will slide down the sclera 342 instead of
entering the sclera 342 at the contact point because the shaft 304
is completely disposed within the sleeve 330 and the protrusion 331
provides adequate surface area at the distal end of sleeve 330 to
prevent enough force from being generated at the distal end of
sleeve 330 that would result in sleeve 330 entering the sclera
342.
[0231] Conversely, if sleeve 330 enters the anterior chamber 341 at
too steep an angle, i.e., the protrusion 331 hit the iris 344 below
the anterior chamber angle 343, the substantially flat bottom
portion of the protrusion 331 causes the sleeve 330 to deflect off
the iris 344 and proceed is a direction parallel to the iris 344
until the protrusion 331 is fit within the anterior chamber angle
343 of the eye 340 (FIGS. 24D and 24E). The sleeve 330 will deflect
off the iris 344 instead of entering the iris 344 at the contact
point because the shaft 304 is completely disposed within the
sleeve 330 and the protrusion 331 provides adequate surface area at
the distal end of sleeve 330 to prevent enough force from being
generated at the distal end of sleeve 330 that would result in
sleeve 330 entering the iris 344.
[0232] In certain embodiments, protrusion 331 is not required. In
these embodiments, the sleeve 330 is of a sufficient outer diameter
such that the sleeve itself may serve the function of the
protrusion as described above. In these embodiments, a distal end
of the sleeve is shaped to have a flat bottom portion and an angled
top portion. In other embodiments, a goniolens can be used to
visualize advancement of the device within the eye, and thus the
configuration of the distal end of the sleeve 330 is not important
for proper shunt deployment using some embodiments of the
device.
[0233] Referring back to FIG. 22A, the proximal portion 301a of the
housing 301 is open at its proximal end, such that a portion of a
deployment mechanism 303 may extend from the proximal end of the
proximal portion 301a of the housing 301. The sleeve 330 of the
distal portion 301b of the housing 301 is also open such that at
least a portion of a hollow shaft 304 may extend inside the
housing, into sleeve 330 of the distal portion 301b of the housing
301, and extend beyond the distal end of the sleeve 330 in certain
configurations (such as the deployment configuration). Housing 301
further includes a slot 306 through which an operator, such as a
surgeon, using the device 300 may view an indicator 307 on the
deployment mechanism 303.
[0234] Housing 301 and protrusion 331 may be made of any material
that is suitable for use in medical devices. For example, housing
301 and protrusion 331 may be made of a lightweight aluminum or a
biocompatible plastic material. Examples of such suitable plastic
materials include polycarbonate and other polymeric resins such as
DELRIN and ULTEM. In certain embodiments, housing 301 and
protrusion 331 are made of a material that may be autoclaved, and
thus allow for housing 301 and protrusion 331 to be re-usable.
Alternatively, device 300, may be sold as a one-time-use device,
and thus the material of the housing and the protrusion does not
need to be a material that is autoclavable.
[0235] Deployment into the eye of an intraocular shunt, such as the
shunts described herein, in accordance with some methods can be
achieved using a hollow shaft configured to hold the shunt, as
described herein. The hollow shaft can be coupled to a deployment
device or part of the deployment device itself. Deployment devices
that are suitable for use with some methods include but are not
limited to the deployment devices described in U.S. Pat. No.
6,007,511, U.S. Pat. No. 6,544,249, and U.S. Pat. Pub. No.
US2008/0108933, the contents of each of which are hereby
incorporated by reference in their entireties. In other
embodiments, the deployment devices are devices as described in
co-pending and co-owned U.S. patent application Ser. No. 12/946,222
filed on Nov. 15, 2010, the entire content of which is incorporated
by reference herein.
[0236] In still other embodiments, some methods are conducted using
the deployment device 400 depicted in FIG. 25. While FIG. 25 shows
a handheld manually operated shunt deployment device, it will be
appreciated that some embodiments of the device may be coupled with
robotic systems and may be completely or partially automated. As
shown in FIG. 25, deployment device 400 includes a generally
cylindrical body or housing 401, however, the body shape of housing
401 could be other than cylindrical. Housing 401 may have an
ergonomical shape, allowing for comfortable grasping by an
operator. Housing 401 is shown with optional grooves 402 to allow
for easier gripping by a surgeon.
[0237] Housing 401 is shown having a larger proximal portion that
tapers to a distal portion. The distal portion includes a hollow
sleeve 405. The hollow sleeve 405 is configured for insertion into
an eye and to extend into an anterior chamber of an eye. The hollow
sleeve is visible within an anterior chamber of an eye. The sleeve
may include an edge at a distal end that provides resistance
feedback to an operator upon insertion of the deployment device 400
within an eye of a person. Upon advancement of the device 400
across an anterior chamber of the eye, the hollow sleeve 405 will
eventually contact the sclera, providing resistance feedback to an
operator that no further advancement of the device 400 is
necessary. The edge of the sleeve 405, prevents the shaft 404 from
accidentally being pushed too far through the sclera. A temporary
guard 408 is configured to fit around sleeve 405 and extend beyond
an end of sleeve 405. The guard is used during shipping of the
device and protects an operator from a distal end of a hollow shaft
404 that extends beyond the end of the sleeve 405. The guard is
removed prior to use of the device.
[0238] Housing 401 is open at its proximal end, such that a portion
of a deployment mechanism 403 may extend from the proximal end of
the housing 401. A distal end of housing 401 is also open such that
at least a portion of a hollow shaft 404 may extend through and
beyond the distal end of the housing 401. Housing 401 further
includes a slot 406 through which an operator, such as a surgeon,
using the device 400 may view an indicator 407 on the deployment
mechanism 403.
[0239] Housing 401 may be made of any material that is suitable for
use in medical devices. For example, housing 401 may be made of a
lightweight aluminum or a biocompatible plastic material. Examples
of such suitable plastic materials include polycarbonate and other
polymeric resins such as DELRIN and ULTEM. In certain embodiments,
housing 401 is made of a material that may be autoclaved, and thus
allow for housing 401 to be re-usable. Alternatively, device 400,
may be sold as a one-time-use device, and thus the material of the
housing does not need to be a material that is autoclavable.
[0240] Housing 401 may be made of multiple components that connect
together to form the housing. FIG. 26 shows an exploded view of
deployment device 400. In this figure, housing 401, is shown having
three components 401a, 401b, and 401c. The components are designed
to screw together to form housing 401. FIG. 26 also shows
deployment mechanism 403. The housing 401 is designed such that
deployment mechanism 403 fits within assembled housing 401. Housing
401 is designed such that components of deployment mechanism 403
are movable within housing 401.
[0241] FIGS. 27A-27D also show deployment mechanism 403. The
housing 401 is designed such that deployment mechanism 403 fits
within assembled housing 401. Housing 401 is designed such that
components of deployment mechanism 403 are movable within housing
401.
[0242] FIGS. 27A-27D show different enlarged views of the
deployment mechanism 403. Deployment mechanism 403 may be made of
any material that is suitable for use in medical devices. For
example, deployment mechanism 403 may be made of a lightweight
aluminum or a biocompatible plastic material. Examples of such
suitable plastic materials include polycarbonate and other
polymeric resins such as DELRIN and ULTEM. In certain embodiments,
deployment mechanism 403 is made of a material that may be
autoclaved, and thus allow for deployment mechanism 403 to be
re-usable. Alternatively, device 400 may be sold as a one-time-use
device, and thus the material of the deployment mechanism does not
need to be a material that is autoclavable.
[0243] Deployment mechanism 403 includes a distal portion 409 and a
distal portion 410. The deployment mechanism 403 is configured such
that distal portion 409 is movable within distal portion 410. More
particularly, distal portion 409 is capable of partially retracting
to within distal portion 410.
[0244] In this embodiment, the distal portion 409 is shown to taper
to a connection with a hollow shaft 404. This embodiment is
illustrated such that the connection between the hollow shaft 404
and the distal portion 409 of the deployment mechanism 403 occurs
inside the housing 401. Hollow shaft 404 may be removable from the
distal portion 409 of the deployment mechanism 403. Alternatively,
the hollow shaft 404 may be permanently coupled to the distal
portion 409 of the deployment mechanism 403.
[0245] Generally, hollow shaft 404 is configured to hold an
intraocular shunt 415. An exemplary intraocular shunt 415 in shown
in FIG. 29. Other exemplary intraocular shunts are shown in Yu et
al. (U.S. Pat. Pub. No. 2008/0108933). Generally, in one
embodiment, intraocular shunts are of a cylindrical shape and have
an outside cylindrical wall and a hollow interior. The shunt may
have an inner diameter of approximately 50 .mu.m to approximately
250 .mu.m, an outside diameter of approximately 190 .mu.m to
approximately 300 .mu.m, and a length of approximately 0.5 mm to
about 20 mm. Thus, hollow shaft 404 is configured to at least hold
a shunt of such shape and such dimensions. However, hollow shaft
404 may be configured to hold shunts of different shapes and
different dimensions than those described above, and some
embodiments encompass a shaft 404 that may be configured to hold
any shaped or dimensioned intraocular shunt. In particular
embodiments, the shaft has an inner diameter of approximately 200
.mu.m to approximately 400 .mu.m. In certain embodiments, the shunt
is a soft gel shunt, e.g., a gelatin shunt. If a gelatin shunt is
used, the shunt is generally wetted inside the hollow shaft 404
with a balanced salt solution (e.g., Dulbecco's Phosphate Buffered
Saline) or a steroid or other drug prior to implantation. Such
priming ensures that the shunt remains flexible before
implantation.
[0246] The shaft 404 may be any length. A usable length of the
shaft may be anywhere from about 5 mm to about 40 mm, and is 15 mm
in certain embodiments. In certain embodiments, the shaft is
straight. In other embodiments, shaft 404 is of a shape other than
straight, for example a shaft having a bend along its length or a
shaft having an arcuate portion. Exemplary shaped shafts are shown
for example in Yu et al. (U.S. Pat. Pub. No. 2008/0108933). In
particular embodiments, the shaft includes a bend at a distal
portion of the shaft. In other embodiments, a distal end of the
shaft is beveled or is sharpened to a point.
[0247] The shaft 404 may hold the shunt at least partially within
the hollow interior of the shaft 404. In other embodiments, the
shunt is held completely within the hollow interior of the shaft
404. Alternatively, the hollow shaft may hold the shunt on an outer
surface of the shaft 404. In particular embodiments, the shunt is
held within the hollow interior of the shaft 404. In certain
embodiments, the hollow shaft is a needle having a hollow interior.
Needles that are configured to hold an intraocular shunt are
commercially available from Terumo Medical Corp. (Elkington,
Md.).
[0248] A proximal portion of the deployment mechanism 403 includes
optional grooves 416 to allow for easier gripping by an operator
for easier rotation of the deployment mechanism, which will be
discussed in more detail below. The proximal portion 410 of the
deployment mechanism also includes at least one indicator that
provides feedback to an operator as to the state of the deployment
mechanism. The indicator may be any type of indicator known in the
art, for example a visual indicator, an audio indicator, or a
tactile indicator. FIGS. 27A-27D show a deployment mechanism having
two indicators, a ready indicator 411 and a deployed indicator 419.
Ready indicator 411 provides feedback to an operator that the
deployment mechanism is in a configuration for deployment of an
intraocular shunt from the deployment device 400. The ready
indicator 411 is shown in this embodiment as a green oval having a
triangle within the oval. Deployed indicator 419 provides feedback
to the operator that the deployment mechanism has been fully
engaged and has deployed the shunt from the deployment device 400.
The deployed indicator 419 is shown in this embodiment as a yellow
oval having a black square within the oval. The indicators are
located on the deployment mechanism such that when assembled, the
indicators 411 and 419 may be seen through slot 406 in housing
401.
[0249] The proximal portion 410 includes a stationary portion 410b
and a rotating portion 410a. The proximal portion 410 includes a
channel 412 that runs part of the length of stationary portion 410b
and the entire length of rotating portion 410a. The channel 412 is
configured to interact with a protrusion 417 on an interior portion
of housing component 401a (FIGS. 28A and 28B). During assembly, the
protrusion 417 on housing component 401a is aligned with channel
412 on the stationary portion 410b and rotating portion 410a of the
deployment mechanism 403. The proximal portion 410 of deployment
mechanism 403 is slid within housing component 401a until the
protrusion 417 sits within stationary portion 410b (FIG. 28C).
Assembled, the protrusion 417 interacts with the stationary portion
410b of the deployment mechanism 403 and prevents rotation of
stationary portion 410b. In this configuration, rotating portion
410a is free to rotate within housing component 401a.
[0250] Referring back to FIGS. 27A-27D, the rotating portion 410a
of proximal portion 410 of deployment mechanism 403 also includes
channels 413a, 413b, and 413c. Channel 413a includes a first
portion 413a1 that is straight and runs perpendicular to the length
of the rotating portion 410a, and a second portion 413a2 that runs
diagonally along the length of rotating portion 410a, downwardly
toward a proximal end of the deployment mechanism 403. Channel 413b
includes a first portion 413b1 that runs diagonally along the
length of the rotating portion 410a, downwardly toward a distal end
of the deployment mechanism 403, and a second portion that is
straight and runs perpendicular to the length of the rotating
portion 410a. The point at which first portion 413a1 transitions to
second portion 413a2 along channel 413a, is the same as the point
at which first portion 413b1 transitions to second portion 413b2
along channel 413b. Channel 413c is straight and runs perpendicular
to the length of the rotating portion 410a. Within each of channels
413a, 413b, and 413c, sit members 414a, 414b, and 414c
respectively. Members 414a, 414b, and 414c are movable within
channels 413a, 413b, and 413c. Members 414a, 414b, and 414c also
act as stoppers that limit movement of rotating portion 410a, which
thereby limits axial movement of the shaft 404.
[0251] FIG. 30 shows a cross-sectional view of deployment mechanism
403. Member 414a is connected to the distal portion 409 of the
deployment mechanism 403. Movement of member 414a results in
retraction of the distal portion 409 of the deployment mechanism
403 to within the proximal portion 410 of the deployment mechanism
403. Member 414b is connected to a pusher component 418. The pusher
component 418 extends through the distal portion 409 of the
deployment mechanism 403 and extends into a portion of hollow shaft
404. The pusher component is involved in deployment of a shunt from
the hollow shaft 404. An exemplary pusher component is a plunger.
Movement of member 414b engages pusher 418 and results in pusher
418 advancing within hollow shaft 404.
[0252] Reference is now made to FIGS. 31A-37B, which accompany the
following discussion regarding deployment of a shunt 415 from
deployment device 400. FIG. 31A shows deployment device 400 in a
pre-deployment or insertion configuration. In this configuration,
shunt 415 is loaded within hollow shaft 404 (FIG. 31B). As shown in
FIG. 31B, shunt 415 is only partially within shaft 404, such that a
portion of the shunt is exposed. However, the shunt 415 does not
extend beyond the end of the shaft 404. In other embodiments, the
shunt 415 is completely disposed within hollow shaft 404. The shunt
415 is loaded into hollow shaft 404 such that the shunt abuts
pusher component 418 within hollow shaft 404.
[0253] In the pre-deployment or insertion configuration, the distal
portion 401b of the housing 401 is in an extended position, with
spring 421 in a relaxed state (FIG. 31A). Additionally, in the
pre-deployment configuration, the shaft 404 is fully disposed
within the sleeve 430 of the distal portion 401b of the housing 401
(FIG. 31B). Pusher 418 abuts shunt 415 (FIG. 31B).
[0254] The deployment mechanism 403 is configured such that member
414a abuts a distal end of the first portion 413a1 of channel 413a,
and member 414b abut a proximal end of the first portion 413b1 of
channel 413b (FIG. 31C). In this configuration, the ready indicator
411 is visible through slot 406 of the housing 401, providing
feedback to an operator that the deployment mechanism is in a
configuration for deployment of an intraocular shunt from the
deployment device 400 (FIG. 31D). In this configuration, the device
400 is ready for insertion into an eye (insertion configuration or
pre-deployment configuration).
[0255] FIGS. 32A-32B show device 400 in the insertion configuration
and inserted into an eye 440. FIG. 32A is a magnified view of the
position of the distal portion 401b relative to the proximal
portion 401a in the insertion configuration. FIG. 32B is a
magnified view of the sleeve 430 of device 400 inserted into the
eye. Any of a variety of methods known in the art may be used to
insert some embodiments of the device into an eye. In certain
embodiments, some embodiments of the device may be inserted into
the eye using an ab externo approach (entering through the
conjunctiva) or an ab interno approach (entering through the
cornea). In particular embodiment, the approach is an ab interno
approach as shown Yu et al. (U.S. Pat. No. 6,544,249 and U.S. Pat.
Pub. No. 2008/0108933) and Prywes (U.S. Pat. No. 6,007,511), the
content of each of which is incorporated by reference herein in its
entirety.
[0256] FIGS. 32A-32B shows an ab interno approach for insertion of
device 400 into the eye 440. In FIG. 32B, protrusion 431 at the
distal end of the sleeve 430 has been advanced across the anterior
chamber 441 to the anterior chamber angle 443 on the opposite side
of the eye 440 from which the device entered the eye 440. FIG. 32B
shows protrusion 431 and sleeve 430 fitted within the anterior
chamber angle 443 of the eye 440, thus re-opening the partially or
completely closed anterior chamber angle 443. Further, FIG. 32B
illustrates that the protrusion 431 at the distal end of the sleeve
430 has been advanced across the anterior chamber 441 to the sclera
442 on the opposite side of the eye 440 from which the device
entered the eye 440. FIG. 32B shows protrusion 431 and sleeve 430
fitted within the anterior chamber angle 443 of the eye 440. Such
insertion and placement is accomplished without the use of an
optical apparatus that contacts the eye, such as a goniolens. In
certain embodiments this insertion is accomplished without the use
of any optical apparatus.
[0257] Insertion without the use of an optical apparatus that
contacts the eye, or any optical apparatus, is possible because of
various features of the device described above and reviewed here
briefly. The shape of the protrusion 431 is such that it corrects
for an insertion angle that is too steep or too shallow, ensuring
that the sleeve 430 is fitted into the anterior chamber angle of
the eye, the place for proper deployment of an intraocular shunt.
Further, the shape of the protrusion provides adequate surface area
at the distal end of sleeve 430 to prevent enough force from being
generated at the distal end of sleeve 430 that would result in
sleeve 430 entering an improper portion of the sclera 442 (if the
insertion angle is too shallow) or entering an improper portion of
the iris 444 (if the insertion angle is too steep). Additionally,
since the hollow shaft 404 is fully disposed within the sleeve 430,
it cannot pierce tissue of the eye until it is extended from the
sleeve 430. Thus, if the insertion angle is too shallow or too
steep, the protrusion 431 can cause movement and repositioning of
the sleeve 430 so that the sleeve 430 is properly positioned to fit
in the anterior chamber angle of the eye for proper deployment of
the shunt. Due to these features of device 400, some embodiments of
the device provide for deploying intraocular shunts without use of
an optical apparatus that contacts the eye, preferably without use
of any optical apparatus.
[0258] Once the device has been inserted into the eye and the
protrusion 431 and the sleeve 430 are fitted within the anterior
chamber angle of the eye, the hollow shaft 404 may be extended from
within the sleeve 430. Referring now to FIG. 33A which show
extension of the hollow shaft 404 from within the sleeve 430, which
is accomplished by partial retraction of distal portion 401b of
housing 401 to within proximal portion 401a of housing 401 (FIG.
33A).
[0259] Retraction of the distal portion 401b of housing 401 to
within proximal portion 401a of housing 401 is accomplished by an
operator continuing to apply force to advance device 400 after the
protrusion 431 and the sleeve 430 are fitted within the anterior
chamber angle of the eye. The surface area of protrusion 431
prevents the application of the additional force by the operator
from advancing sleeve 430 into the sclera 434. Rather, the
additional force applied by the operator results in engagement of
spring mechanism 420 and compression of spring 421 within spring
mechanism 420. Compression of spring 420 results in retraction of
distal portion 401b of housing 401 to within proximal portion 401a
of housing 401. The amount of retraction of distal portion 401b of
housing 401 to within proximal portion 401a of housing 401 is
limited by member 422 that acts as a stopper and limits axial
retraction of distal portion 401b within proximal portion 401a.
[0260] Retraction of distal portion 401b of housing 401 to within
proximal portion 401a of housing 401 results in extension of hollow
shaft 404, which now extends beyond the distal end of sleeve 430
and advances through the sclera 442 to an area of lower pressure
than the anterior chamber (see e.g., FIG. 33B).
[0261] In FIG. 33A, a distal end of the shaft is shown to be
located within the intra-Tenon's space. Within an eye, there is a
membrane known as the conjunctiva, and the region below the
conjunctiva is known as the subconjunctival space. Within the
subconjunctival space is a membrane known as Tenon's capsule. Below
Tenon's capsule there are Tenon's adhesions that connect the
Tenon's capsule to the sclera. The space between Tenon's capsule
and the sclera where the Tenon's adhesions connect the Tenon's
capsule to the sclera is known as the intra-Tenon's space. This
figure is exemplary and depicts only one embodiment for a location
of lower pressure. It will be appreciated that some embodiments of
the device may deploy shunts to various different locations of the
eye and are not limited to deploying shunts to the intra-Tenon's
space is shown by way of example in this figure. In this
configuration, the shunt 415 is still completely disposed within
the shaft 404.
[0262] The distal end of shaft 404 may be beveled to assist in
piercing the sclera and advancing the distal end of the shaft 404
through the sclera. In this figure, the distal end of the shaft 404
is shown to have a double bevel (See also FIG. 31B). The double
bevel provides an angle at the distal end of the shaft 404 such
that upon entry of the shaft into intra-Tenon's space, the distal
end of shaft 404 will by parallel with Tenon's capsule and will
thus not pierce Tenon's capsule and enter the subconjunctival
space. This ensures proper deployment of the shunt such that a
distal end of the shunt 415 is deployed within the intra-Tenon's
space, rather than deployment of the distal end of the shunt 415
within the subconjunctival space. Changing the angle of the bevel
allows for placement of shunt 415 within other areas of lower
pressure than the anterior chamber, such as the subconjunctival
space. It will be understood that FIG. 33A-33B is merely one
embodiment of where shunt 415 may be placed within the eye, and
that some embodiments of the device are not limited to placing
shunts within intra-Tenon's space and may be used to place shunts
into many other areas of the eye, such as Schlemm's canal, the
subconjunctival space, the episcleral vein, or the suprachoroidal
space.
[0263] Referring to FIG. 33B, as noted above, retraction of distal
portion 401b of housing 401 to within proximal portion 401a of
housing 401 results in extension of hollow shaft 404, which now
extends beyond the distal end of sleeve 430 and advances through
the sclera 442. In accordance with some embodiments, the rigidity
of the sleeve 430 holds hollow shaft 404 in a straight
configuration. Upon its exposure from the sleeve 430, hollow shaft
404 reverts to its pre-bent configuration, which bend minors the
angle or arc of the sclera. Such a pre-bend allows the hollow shaft
404 to follow the scleral spur down along the sclera in a
self-guided manner to the suprachoroidal space. Generally, the bend
in the hollow shaft 404 will be from about 5.degree. degrees to
about 70.degree. degrees.
[0264] Additionally, the flexibility of the hollow shaft 404 allows
it to continually bend and flex in response to the anatomy as the
hollow shaft 404 advances from the sleeve 430. The hollow shaft 404
is advanced until a distal portion of the hollow shaft 404 is
within the suprachoroidal space. In this configuration, the shunt
415 is still completely disposed within the shaft 404. The distal
end of hollow shaft 404 may be beveled to assist in piercing the
sclera and advancing the distal end of the hollow shaft 404 through
the sclera.
[0265] At this point, an amount of BSS/steroid or other drug can be
optionally injected through the hollow shaft and implant into a
lower end of the target space to create a primed space for outflow
and to deliver antifibrotic or other drugs to that new drainage
space.
[0266] Reference is now made to FIGS. 34A to 34D. After extension
of hollow shaft 404 from sleeve 430, the shunt 415 may be deployed
from the device 400. The deployment mechanism 403 is a two-stage
system. The first stage is engagement of the pusher component 418
and the second stage is retraction of the distal portion 409 of
deployment mechanism 403 to within the proximal portion 410 of the
deployment mechanism 403. Rotation of the rotating portion 410a of
the proximal portion 410 of the deployment mechanism 403
sequentially engages the pusher component and then the retraction
component.
[0267] In the first stage of shunt deployment, the pusher component
is engaged and the pusher partially deploys the shunt from the
deployment device. During the first stage, rotating portion 410a of
the proximal portion 410 of the deployment mechanism 403 is
rotated, resulting in movement of members 414a and 414b along first
portions 413a1 and 413b1 in channels 413a and 413b. Since the first
portion 413a1 of channel 413a is straight and runs perpendicular to
the length of the rotating portion 410a, rotation of rotating
portion 410a does not cause axial movement of member 414a. Without
axial movement of member 414a, there is no retraction of the distal
portion 409 to within the proximal portion 410 of the deployment
mechanism 403. Since the first portion 413b1 of channel 413b runs
diagonally along the length of the rotating portion 410a, upwardly
toward a distal end of the deployment mechanism 403, rotation of
rotating portion 410a causes axial movement of member 414b toward a
distal end of the device. Axial movement of member 414b toward a
distal end of the device results in forward advancement of the
pusher component 418 within the hollow shaft 404. Such movement of
pusher component 418 results in partially deployment of the shunt
415 from the shaft 404.
[0268] FIGS. 34A-34C show schematics of the deployment mechanism at
the end of the first stage of deployment of the shunt from the
deployment device. FIGS. 34A-34B show the shaft in a straight
configuration, as if it is within the stiff outer sleeve. As is
shown FIG. 34A, members 414a and 414b have finished traversing
along first portions 413a1 and 413b1 of channels 413a and 413b.
Additionally, pusher component 418 has advanced within hollow shaft
404 (FIG. 34B), and shunt 415 has been partially deployed from the
hollow shaft 404 (FIG. 34C). As is shown in FIG. 34D, a portion of
the shunt 415 extends beyond an end of the shaft 404.
[0269] FIGS. 35A-35B show device 400 at the end of the first stage
of deployment of the shunt 415 from device 400 and into the eye
440. This figure shows that the distal portion 401b of the housing
401 remains retracted within the proximal portion 401a of the
housing 401, and that the hollow shaft 404 remains extended from
the sleeve 430. As is shown in these figures, pusher 418 has been
engaged and, which allows shunt 415 to be deployed from the hollow
shaft 404. A portion of the shunt 415 can extend beyond an end of
the shaft 404 and be located in the intra-Tenon's space.
[0270] Reference is now made to FIGS. 36A-36D. In the second stage
of shunt deployment, the retraction component of deployment
mechanism is engaged and the distal portion of the deployment
mechanism is retracted to within the proximal portion of the
deployment mechanism, thereby completing deployment of the shunt
from the deployment device. During the second stage, rotating
portion 410a of the proximal portion 410 of the deployment
mechanism 403 is further rotated, resulting in movement of members
414a and 414b along second portions 413a2 and 413b2 in channels
413a and 413b. Since the second portion 413b2 of channel 413b is
straight and runs perpendicular to the length of the rotating
portion 410a, rotation of rotating portion 410a does not cause
axial movement of member 414b. Without axial movement of member
414b, there is no further advancement of pusher 418. Since the
second portion 413a2 of channel 413a runs diagonally along the
length of the rotating portion 410a, downwardly toward a proximal
end of the deployment mechanism 403, rotation of rotating portion
410a causes axial movement of member 414a toward a proximal end of
the device. Axial movement of member 414a toward a proximal end of
the device results in retraction of the distal portion 409 to
within the proximal portion 410 of the deployment mechanism 403.
Retraction of the distal portion 409, results in retraction of the
hollow shaft 404. Since the shunt 415 abuts the pusher component
418, the shunt remains stationary as the hollow shaft 404 retracts
from around the shunt 415. The hollow shaft 404 retracts completely
to within the sleeve 430 of the distal portion 401b of the housing
401. During both stages of the deployment process, the sleeve 430
remains stationary and in a fixed position.
[0271] Referring to FIGS. 36A-36D, which show schematics of the
deployment mechanism at the end of the second stage of deployment
of the shunt from the deployment device. As is shown in FIG. 36A,
members 414a and 414b have finished traversing along second
portions 413a2 and 413b2 of channels 413a and 413b. Additionally,
distal portion 409 has retracted to within proximal portion 410,
thus resulting in retraction of the hollow shaft 404 to within the
sleeve 430. FIG. 36A shows the shaft in a straight configuration,
after it has been retracted into the stiff outer sleeve.
[0272] FIGS. 36B and 36C show a schematic of the device 400 in the
eye 430 after the second stage of deployment has been completed.
FIG. 36B shows that the distal portion 401b of the housing 401
remains retracted within the proximal portion 401a of the housing
401. As is shown in FIGS. 36B and 36C, shaft 404 has withdrawn
through the sclera 434 to be fully retracted to within sleeve 430.
At completion of the second stage of deployment, a distal portion
of the shunt 415 has been deployed and resides in the intra-Tenon's
space (see FIG. 36B) or in the suprachoroidal space (see FIG. 36C),
a middle portion of the shunt 415 spans the sclera, and a proximal
portion of shunt 415 has been deployed from shaft 404 yet still
resides within sleeve 430. The proximal portion of the shunt 415
still abuts pusher 418.
[0273] Referring to FIG. 36D, in the post-deployment configuration,
the deployed indicator 419 is visible through slot 406 of the
housing 401, providing feedback to the operator that the deployment
mechanism 403 has been fully engaged and that the deployment
mechanism 403 has completed its second stage of deployment.
[0274] Referring to FIG. 37A-37B, which show schematics of the
device 400 after completion of deployment of the shunt 415 from the
device 400 and in to the eye 440. After completion of the second
stage of the deployment by the deployment mechanism 403, as
indicated to the operator by visualization of deployed indicator
419 through slot 406 of the housing 401, the operator may pull the
device 400 from the eye 440. Backward force by the operator
reengages spring mechanism 420 and results in uncoiling of spring
421 (FIG. 37A). Uncoiling of spring 421 proceeds as the proximal
portion 401a of housing 401 is pulled from the eye 440. Such action
causes distal portion 401b to return to its extended state within
proximal portion 401a of housing 401 (FIG. 37A). Continued backward
force by the operator continues to pull the device 400 from the eye
440. As the device 400 is continued to be pulled from the eye, the
sleeve 430 is also pulled backward and the proximal portion of the
shunt 415 is exposed from within the sleeve 430 and resides within
the anterior chamber 441 of the eye 440 (FIG. 37B). The operator
continues to apply backward force until the device 400 is
completely withdrawn from the eye 440. At this point, in some
embodiments, a distal portion of the shunt 415 has been deployed
and can reside in the suprachoroidal space (see FIGS. 36C and 37B),
a middle portion of the shunt 415 spans the sclera, and a proximal
portion of shunt 415 has been deployed and resides in the anterior
chamber.
Three Stage Deployment Mechanism
[0275] Another embodiment by which the hollow shaft 404 may be
extended from the sleeve 430 involves a deployment mechanism that
is a three-stage mechanism. The three-stage mechanism operates
similarly to the above described device that uses a spring loaded
distal portion and a two-stage deployment mechanism. In the
three-stage system, the channels of the deployment mechanism are
extended to accommodate the new first stage. The newly added
portion of the channels run diagonally upward along the length of
the rotating portion toward the proximal end of the deployment
mechanism. Axial movement by the members within the channels
results in the extension of the hollow shaft 404 from the sleeve
430. The new first stage replaces the spring loaded distal portion
and results in extension of the hollow shaft 404 from the sleeve
430. The engagement of the pusher component 418 becomes the second
stage and retraction of the distal portion 409 of deployment
mechanism 403 to within the proximal portion 410 of the deployment
mechanism 403 becomes the third stage. The second and third stages
of the three-stage system are the same as the first and second
stages of the two-stage system and operate as described above.
Rotation of the rotating portion of the distal portion of the
deployment mechanism sequentially extends the hollow shaft from the
sleeve, engages the pusher component and then engages the
retraction component.
[0276] Referring now to FIGS. 38A-38E, the sleeve 505 may include
an edge 531 at a distal end that provides resistance feedback to an
operator upon insertion of the deployment device 500 within an eye
532 of a person during delivery of the shunt 515. Upon advancement
of the device 500 across an anterior chamber 533 of the eye 532,
the hollow sleeve 505 will eventually contact the sclera 534,
providing resistance feedback to an operator that no further
advancement of the device 500 is necessary. The edge 531 of the
sleeve 505 prevents the shaft 504 from accidentally being pushed
too far through the sclera 534.
Combinations of Embodiments
[0277] As will be appreciated by one skilled in the art, individual
features of some embodiments may be used separately or in any
combination. Particularly, it is contemplated that one or more
features of the individually described above embodiments may be
combined into a single shunt.
INCORPORATION BY REFERENCE
[0278] References and citations to other documents, such as
patents, patent applications, patent publications, journals, books,
papers, web contents, have been made throughout this disclosure.
All such documents are hereby incorporated herein by reference in
their entirety for all purposes.
EQUIVALENTS
[0279] The inventions may be embodied in other specific forms
without departing from the spirit or essential characteristics
thereof. The foregoing embodiments are therefore to be considered
in all respects illustrative rather than limiting on the inventions
described herein.
* * * * *