U.S. patent application number 17/718130 was filed with the patent office on 2022-09-29 for intraocular shunt implantation.
The applicant listed for this patent is AqueSys, Inc.. Invention is credited to Christopher HORVATH, Richard A. LEWIS, Laszlo O. ROMODA.
Application Number | 20220304856 17/718130 |
Document ID | / |
Family ID | 1000006394980 |
Filed Date | 2022-09-29 |
United States Patent
Application |
20220304856 |
Kind Code |
A1 |
HORVATH; Christopher ; et
al. |
September 29, 2022 |
INTRAOCULAR SHUNT IMPLANTATION
Abstract
Glaucoma can be treated by implanting an intraocular shunt in
the eye. The implantation can be performed by first determining an
entry area below a corneal limbus of an eye. Thereafter, the
intraocular shunt can be inserted into eye tissue through the entry
area such that an inflow end of the shunt is positioned in the
anterior chamber of the eye and an outflow end of the shunt is
positioned between layers of Tenon's capsule.
Inventors: |
HORVATH; Christopher;
(Mission Viejo, CA) ; ROMODA; Laszlo O.; (San
Clemente, CA) ; LEWIS; Richard A.; (Sacramento,
CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
AqueSys, Inc. |
Parsippany |
NJ |
US |
|
|
Family ID: |
1000006394980 |
Appl. No.: |
17/718130 |
Filed: |
April 11, 2022 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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16509458 |
Jul 11, 2019 |
11298264 |
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17718130 |
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|
15703802 |
Sep 13, 2017 |
10369048 |
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16509458 |
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|
14317676 |
Jun 27, 2014 |
9808373 |
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15703802 |
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61841224 |
Jun 28, 2013 |
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61895341 |
Oct 24, 2013 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61F 9/00781
20130101 |
International
Class: |
A61F 9/007 20060101
A61F009/007 |
Claims
1. A method of treating glaucoma comprising determining an entry
area below a corneal limbus of an eye and inserting an intraocular
shunt into eye tissue through the entry area such that an inflow
end of the shunt is positioned in the anterior chamber of the eye
and an outflow end of the shunt is positioned adjacent to Tenon's
capsule.
2. The method of claim 1, wherein inserting an intraocular shunt
into eye tissue comprises forming a passageway through the
sclera.
3. The method of claim 1, wherein a device for deploying the
intraocular shunt comprises a shaft configured to hold the shunt,
and wherein the inserting comprises advancing the shaft through the
sclera until reaching a first position at which a bevel of the
shaft is positioned in the anterior chamber of the eye.
4. The method of claim 3, wherein after reaching the first
position, the inserting comprises advancing a pusher component of
the device such that the shunt is pushed distally out of the
shaft.
5. The method of claim 4, wherein the advancing the pusher
component comprises pushing less than an entire length of the shunt
distally out of the shaft.
6. The method of claim 4, wherein the device comprises a sleeve
having a distal end and a lumen, the shaft being disposed within
the lumen, wherein the inserting further comprises advancing the
pusher component to a distal most position at which a distal end of
the pusher component is positioned longitudinally proximal to the
sleeve distal end.
7. The method of claim 4, wherein the device comprises a sleeve
having a distal end and a lumen, the shaft being disposed within
the lumen, and wherein at the first position, the sleeve distal end
is spaced apart from the eye tissue.
8. The method of claim 7, wherein the inserting further comprises
advancing the pusher component until a distal end of the pusher
component is positioned longitudinally adjacent to the sleeve
distal end.
9. The method of claim 7, wherein the sleeve distal end is spaced
apart from anterior chamber angle tissue in the first position.
10. The method of claim 7, wherein the inserting further comprises,
while maintaining the shaft substantially fixed relative to the
sclera, advancing the sleeve distally over the shaft until the
sleeve distal end contacts eye tissue.
11. The method of claim 10, wherein after the sleeve distal end
contacts the eye tissue, the inserting further comprises proximally
withdrawing the shaft from the sclera until the bevel is received
within a lumen of the sleeve.
12. The method of claim 4, wherein the device comprises a sleeve
having a distal end comprising a beveled shape that corresponds
with an anatomical angle of the entry area surface of the eye.
13. A method of treating glaucoma comprising determining an entry
area posterior to a corneal limbus of an eye and inserting an
intraocular shunt into eye tissue through the entry area such that
first end of the shunt is positioned in the anterior chamber of the
eye and a second end of the shunt is positioned between layers of
Tenon's capsule.
14. The method of claim 13, wherein a device for deploying the
intraocular shunt comprises a shaft configured to hold the shunt,
and wherein the inserting comprises advancing the shaft through the
sclera until reaching a first position at which a distal end of the
shaft is positioned in the anterior chamber of the eye.
15. The method of claim 14, wherein after reaching the first
position, the inserting comprises advancing a pusher component of
the device such that the shunt is pushed distally out of the
shaft.
16. The method of claim 15, wherein the advancing the pusher
component comprises pushing less than an entire length of the shunt
distally out of the shaft.
17. An ab externo intraocular shunt insertion technique wherein the
shunt enters an eye via the sclera and is positioned so as to
extend from the anterior chamber of the eye to a region between
layers of Tenon's capsule.
18. The method of claim 17, wherein a device for deploying the
intraocular shunt comprises a shaft configured to hold the shunt,
and wherein the inserting comprises advancing the shaft through the
sclera until reaching a first position at which a distal end of the
shaft is positioned in the anterior chamber of the eye.
19. The method of claim 18, wherein after reaching the first
position, the inserting comprises advancing a pusher component of
the device such that the shunt is pushed distally out of the
shaft.
20. The method of claim 19, wherein the advancing the pusher
component comprises pushing less than an entire length of the shunt
distally out of the shaft.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation application of U.S.
patent application Ser. No. 16/509,458, filed on Jul. 11, 2019,
which is a continuation application of U.S. patent application Ser.
No. 15/703,802, filed on Sep. 13, 2017, now U.S. Pat. No.
10,369,048, which is a continuation application of U.S. patent
application Ser. No. 14/317,676, filed on Jun. 27, 2014, now U.S.
Pat. No. 9,808,373, which claims the priority benefit of U.S.
Provisional Application No. 61/841,224, filed on Jun. 28, 2013, and
U.S. Provisional Application No. 61/895,341, filed on Oct. 24,
2013, the entirety of each of which is incorporated herein by
reference.
BACKGROUND
Field of the Inventions
[0002] The present disclosure generally relates to devices and
methods of implanting an intraocular shunt into an eye.
Description of the Related Art
[0003] Glaucoma is a disease in which the optic nerve is damaged,
leading to progressive, irreversible loss of vision. It is
typically associated with increased pressure of the fluid (i.e.,
aqueous humor) in the eye. Untreated glaucoma leads to permanent
damage of the optic nerve and resultant visual field loss, which
can progress to blindness. Once lost, this damaged visual field
cannot be recovered. Glaucoma is the second leading cause of
blindness in the world, affecting 1 in 200 people under the age of
fifty, and 1 in 10 over the age of eighty for a total of
approximately 70 million people worldwide.
[0004] The importance of lowering intraocular pressure (IOP) in
delaying glaucomatous progression has been well documented. When
drug therapy fails, or is not tolerated, surgical intervention is
warranted. Surgical filtration methods for lowering intraocular
pressure by creating a fluid flow-path between the anterior chamber
and an area of lower pressure have been described. Intraocular
shunts can be positioned in the eye to drain fluid from the
anterior chamber to locations such as the sub-Tenon's space, the
subconjunctival space, the episcleral vein, the suprachoroidal
space, Schlemm's canal, and the intrascleral space.
[0005] Positioning of an intraocular shunt to drain fluid into the
intrascleral space is promising because it avoids contact with the
conjunctiva and the supra-choroidal space. Avoiding contact with
the conjunctiva and supra-choroid is important because it reduces
irritation, inflammation and tissue reaction that can lead to
fibrosis and reduce the outflow potential of the subconjunctival
and suprachoroidal space. The conjunctiva itself plays a critical
role in glaucoma filtration surgery. A less irritated and healthy
conjunctiva allows drainage channels to form and less opportunity
for inflammation and scar tissue formation. Intrascleral shunt
placement safeguards the integrity of the conjunctiva and choroid,
but may provide only limited outflow pathways that may affect the
long term IOP lowering efficacy.
SUMMARY
[0006] According to some embodiments, methods and devices are
provided for positioning an intraocular shunt within the eye to
treat glaucoma. Various methods are disclosed herein which allow a
clinician to create a fluid pathway from the anterior chamber to an
area of lower pressure within the eye. Although methods may be
discussed in the context of positioning an outflow end of a shunt
in a particular location (e.g., between layers of Tenon's capsule),
the methods disclosed herein can be used to create a fluid pathway
in which the outflow end of the shunt is positioned in other areas
of low pressure, such as the supraciliary space, suprachoroidal
space, the intrascleral space (i.e., between layers of sclera),
intra-Tenon's adhesion space (i.e., between layers of Tenon's
capsule), or subconjunctival space.
[0007] For example, a method of treating glaucoma is disclosed that
can comprise inserting an intraocular shunt into eye tissue such
that an inflow end of the shunt is positioned in the anterior
chamber of the eye and an outflow end of the shunt is positioned
between layers of Tenon's capsule. The shunt can comprise a lumen
that extends between the inflow and outflow ends and that is
configured to permit flow of aqueous humor from the inflow end
through the shunt to the outflow end.
[0008] In accordance with some embodiments, the shunt can be
introduced into the eye through the cornea. After introducing the
shunt through the cornea, the shunt can be advanced into the
sclera. For example, the shunt can be advanced into the sclera
through the anterior chamber angle tissue.
[0009] In some embodiments, the device comprises a shaft that can
be advanced into the sclera until reaching and no further than a
first position at which a bevel of the shaft is positioned between
the layers of Tenon's capsule.
[0010] In some embodiments, after the shaft is positioned within
the sclera (e.g., after the shaft reaches the first position), a
pusher component of the device can be advanced relative to the
shaft such that the shunt is pushed distally out of the shaft.
Although the entire shunt can be advanced out of the shaft by the
pusher component, the method can be implemented such that less than
an entire length of the shunt is pushed distally out of the
shaft.
[0011] The device can comprise a sleeve having a lumen and a distal
end. The shaft can be received within the lumen of the sleeve.
[0012] In some embodiments, after the shaft is positioned within
the sclera (e.g., after the shaft reaches the first position), the
pusher component can be advanced to a distalmost position at which
a distal end of the pusher component is positioned longitudinally
proximal to the sleeve distal end. Further, the pusher component
can also be advanced to a distalmost position at which a distal end
of the pusher component is positioned longitudinally adjacent to
the sleeve distal end.
[0013] Further, in some embodiments, the shaft can be positioned
within the sclera (e.g., after the shaft reaches the first
position) such that a distal end of the sleeve is spaced apart from
the eye tissue. Once the shaft is in place, the pusher component
can be advanced until a distal end of the pusher component is
positioned longitudinally proximal to or adjacent to the sleeve
distal end or the bevel. Furthermore, after the shunt has been at
least partially advanced out of the bevel, the shaft can be
proximally retracted into the sleeve. Proximal retraction of the
shaft into the sleeve can be performed with the shaft maintaining
its position relative to and within the sclera or with the sleeve
maintaining its position relative to the sclera (whether spaced
apart from the eye tissue or abutting the eye tissue), as discussed
herein.
[0014] Moreover, as noted herein, some embodiments of the methods
can be performed whether the outflow end of the shunt is positioned
between layers of Tenon's capsule or whether the outflow end of the
shunt is positioned in another area of low pressure.
[0015] For example, referring to embodiments in which the shunt
outflow end is positioned between layers of Tenon's capsule, the
device can be at the first position and a distal end of the sleeve
can be spaced apart from the eye tissue, such as the anterior
chamber angle tissue. Thereafter, while maintaining the position of
the shaft relative to the sclera, the sleeve can be advanced
distally over the shaft until the distal end of the sleeve contacts
eye tissue, such as the anterior chamber angle tissue. After the
sleeve distal end contacts the tissue, the shaft can be proximally
withdrawn from the sclera until the bevel is received within a
lumen of the sleeve. However, in some embodiments, the sleeve
distal end can be maintained at a given position relative to the
eye tissue (whether the sleeve distal end is spaced apart from or
abutting the eye tissue) while the shaft is withdrawn into the
sleeve.
[0016] In some embodiments, a method of treating glaucoma is
provided that can comprise inserting an intraocular shunt into eye
tissue such that the shunt conducts fluid from the anterior chamber
of the eye to a region between layers of Tenon's capsule. Further,
in some embodiments, the method can comprise inserting an
intraocular shunt into eye tissue such that the shunt conducts
fluid from the anterior chamber of the eye to the intra-Tenon's
adhesion space of the eye.
[0017] The method can also be performed such that a hollow shaft is
inserted into the eye through the cornea. The shaft can be
configured to hold the shunt. For example, the shaft can be enter
the eye through the cornea. The intra-Tenon's adhesion space can
comprise a deep layer and a superficial layer, and an outflow end
of the shunt can be positioned between the deep and superficial
layers.
[0018] Further, a bevel of a shaft can be advanced to a position
between the deep and superficial layers, and while maintaining the
bevel stationary relative to the eye tissue, the shunt can be
distally advanced from the shaft into the intra-Tenon's adhesion
space.
[0019] In accordance with some embodiments, a method of treating
glaucoma is disclosed that can comprise advancing a shaft of a
device into eye tissue until a bevel of the shaft reaches a target
area. Then, while maintaining the bevel substantially stationary
relative to the target area, the sleeve of the device can be
advanced distally over the shaft until a distal end of the sleeve
contacts the eye tissue. Thereafter, upon contacting the sleeve
distal end with the eye tissue, the shaft can be proximally
withdrawn from the eye tissue.
[0020] Additionally, while maintaining the bevel substantially
stationary relative to the target area, a plunger can be advanced
within the shaft to advance a shunt until the shunt extends into
the target area. For example, less than an entire length of the
shunt can be pushed distally out of the shaft. The plunger can be
advanced until a distal end of the plunger is positioned
longitudinally adjacent to the sleeve distal end. The shunt can be
introduced into the eye through the cornea. The target area can be
selected from supraciliary space, suprachoroidal space, a space
between layers of sclera (i.e., intrascleral space), a space
between layers of Tenon's capsule (i.e., intra-Tenon's adhesion
space), or subconjunctival space. The sleeve can be advanced
between about 1 mm to about 4 mm. Further, in some embodiments, the
sleeve can be advanced between about 2 mm to about 3 mm.
[0021] For example, in some embodiments, a method of deploying an
intraocular shunt into an eye is provided. The method can comprise
the steps of: inserting into the eye a hollow shaft configured to
hold the intraocular shunt; and advancing the shunt from the hollow
shaft such that the shunt forms a passage from the anterior chamber
of the eye to the intra-Tenon's adhesion space of the eye.
[0022] The inserting step can further comprise the step of
injecting an aqueous solution into the eye. For example, the
aqueous solution can be injected below Tenon's capsule. The
inserting step can also comprise ab interno insertion of the hollow
shaft into the eye. Ab interno insertion can comprise inserting the
hollow shaft into the eye above the corneal limbus. Further, ab
interno insertion can comprise inserting the hollow shaft into the
eye below the corneal limbus.
[0023] Additionally, some methods can comprise: inserting into the
eye a hollow shaft configured to hold the intraocular shunt, a
portion of the hollow shaft extending linearly along a longitudinal
axis, and at least one other portion of the hollow shaft extending
off the longitudinal axis; and advancing the shunt from the hollow
shaft such that the shunt forms a passage from the anterior chamber
of the eye to the intra-Tenon's adhesion space.
[0024] In accordance with some embodiments, a method of treating
glaucoma can also comprise inserting an intraocular shunt into eye
tissue such that an inflow end of the shunt is positioned in the
anterior chamber of the eye and an outflow end of the shunt is
positioned between layers of Tenon's capsule. The layers of Tenon's
capsule can comprise a deep layer and a superficial layer.
[0025] Some embodiments of the methods disclosed herein such that
the inserting step can further comprise the step of injecting an
aqueous solution into the eye. For example, an aqueous solution can
be injected below Tenon's capsule. The inserting step can also
comprise ab interno insertion of the hollow shaft into the eye. Ab
interno insertion can comprise inserting the hollow shaft into the
eye above the corneal limbus. Ab interno insertion can comprise
inserting the hollow shaft into the eye below the corneal
limbus.
[0026] Some embodiments of the methods disclosed herein can be
implemented such that the inserting step comprises ab interno
insertion of the hollow shaft into the eye.
[0027] Some embodiments of the methods disclosed herein can be
implemented such that the hollow shaft is inserted into the eye
without removing an anatomical feature of the eye.
[0028] The anatomical feature of the eye can be selected from the
group consisting of: the trabecular meshwork, the iris, the cornea,
and the aqueous humor. In accordance with some embodiments, the
method can be performed without inducing subconjunctival blebbing
or endophthalmitis.
[0029] Additional features and advantages of the subject technology
will be set forth in the description below, and in part will be
apparent from the description, or may be learned by practice of the
subject technology. The advantages of the subject technology will
be realized and attained by the structure particularly pointed out
in the written description and embodiments hereof as well as the
appended drawings.
[0030] It is to be understood that both the foregoing general
description and the following detailed description are exemplary
and explanatory and are intended to provide further explanation of
the subject technology.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] Various features of illustrative embodiments are described
below with reference to the drawings. The illustrated embodiments
are intended to illustrate, but not to limit, the inventions. The
drawings contain the following figures:
[0032] FIG. 1 provides a cross-sectional diagram of the general
anatomy of the eye.
[0033] FIG. 2 is an enlarged cross-sectional diagram of the eye
taken along section lines 2-2 of FIG. 1.
[0034] FIG. 3 depicts, implantation of an intraocular shunt with a
distal end of a deployment device holding a shunt, shown in
cross-section, according to some embodiments.
[0035] FIG. 4 depicts an intraocular shunt at least partially
disposed within a hollow shaft of a deployment device, according to
some embodiments.
[0036] FIG. 5 provides a schematic of a shunt having a flexible
portion, according to some embodiments.
[0037] FIGS. 6A-6C 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, according to some
embodiments.
[0038] FIG. 7A 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.
[0039] FIG. 7B shows another embodiment of a shunt in which the
proximal portion includes a single port and the distal portion
includes more than one port.
[0040] FIG. 7C 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.
[0041] FIGS. 8A-8B show different embodiments of multi-port shunts
having different diameter ports.
[0042] FIGS. 9A-9C provide schematics of shunts having a slit
located along a portion of the length of the shunt, according to
some embodiments.
[0043] FIG. 10 depicts a shunt having multiple slits along a length
of the shunt, according to some embodiments.
[0044] FIG. 11 depicts a shunt having a slit at a proximal end of
the shunt, according to some embodiments.
[0045] FIG. 12 provides a schematic of a shunt that has a variable
inner diameter, according to some embodiments.
[0046] FIGS. 13A-13D depict a shunt having multiple prongs at a
distal and/or proximal end, according to some embodiments.
[0047] FIGS. 14A-14D depict a shunt having a longitudinal slit at a
distal and/or proximal end, according to some embodiments.
[0048] FIG. 15 is a schematic showing an embodiment of a shunt
deployment device.
[0049] FIG. 16 shows an exploded view of the device shown in FIG.
16.
[0050] FIGS. 17A-17D are schematics showing different enlarged
views of the deployment mechanism of the deployment device,
according to some embodiments.
[0051] FIGS. 18A-18C are schematics showing interaction of the
deployment mechanism with a portion of the housing of the
deployment device, according to some embodiments.
[0052] FIG. 19 shows a cross-sectional view of the deployment
mechanism of the deployment device, according to some
embodiments.
[0053] FIGS. 20A-20B show schematics of the deployment mechanism in
a pre-deployment configuration, according to some embodiments.
[0054] FIG. 20C shows an enlarged view of the distal portion of the
deployment device of FIG. 20A, with an intraocular shunt loaded
within a hollow shaft of the deployment device, according to some
embodiments.
[0055] FIGS. 21A-21B show schematics of the deployment mechanism at
the end of the first stage of deployment of the shunt from the
deployment device, according to some embodiments.
[0056] FIG. 21C shows an enlarged view of the distal portion of the
deployment device of FIG. 21A, with an intraocular shunt partially
deployed from within a hollow shaft of the deployment device,
according to some embodiments.
[0057] FIG. 22A shows a schematic of the deployment device after
deployment of the shunt from the device, according to some
embodiments.
[0058] FIG. 22B show a schematic of the deployment mechanism at the
end of the second stage of deployment of the shunt from the
deployment device, according to some embodiments.
[0059] FIG. 22C shows an enlarged view of the distal portion of the
deployment device after retraction of the shaft with the pusher
abutting the shunt, according to some embodiments.
[0060] FIG. 22D shows an enlarged view of the distal portion of the
deployment device after deployment of the shunt, according to some
embodiments.
[0061] FIGS. 23-30 depict a sequence for ab interno shunt
placement, according to some embodiments.
[0062] FIG. 31 depicts an implanted shunt in an S-shaped scleral
passageway, according to some embodiments.
[0063] FIG. 32 depicts an example of a hollow shaft configured to
hold an intraocular shunt fully within the shaft, according to some
embodiments.
[0064] FIGS. 33-39 depict a sequence for ab externo shunt
placement, according to some embodiments.
[0065] FIGS. 40-41 depict a sequence for ab externo insertion of a
shaft of a deployment device using an applicator, according to some
embodiments.
[0066] FIG. 42 depicts deployment of the shunt in the intra scleral
space where a distal end of the shunt is flush with the sclera
surface, according to some embodiments.
[0067] FIG. 43 depicts deployment of the shunt in the intra scleral
space where a distal end of the shunt is about 200-500 micron
behind the scleral exit, according to some embodiments.
[0068] FIG. 44 depicts deployment of the shunt in the intra scleral
space where a distal end of the shunt is more than about 500 micron
behind the scleral exit, according to some embodiments.
[0069] FIG. 45 depicts placement of a shunt in the supraciliary
space, according to some embodiments.
[0070] FIG. 46 depicts placement of a shunt in the suprachoroidal
space, according to some embodiments.
[0071] FIG. 47 depicts placement of a shunt in the subconjunctival
space, according to some embodiments.
[0072] FIG. 48 depicts placement of a shunt in the intrascleral
space, according to some embodiments.
[0073] FIG. 49 depicts placement of a shunt in the intra-Tenon's
adhesion space, according to some embodiments.
[0074] FIG. 50 is an enlarged schematic cross-sectional view taken
along section 50 of FIG. 49.
[0075] FIG. 51 is a perspective view taken along section lines
51-51 of FIG. 50.
[0076] FIGS. 52A-52E depict an intraocular shunt being deployed
within the eye, according to another embodiment.
[0077] FIGS. 53A-53E depict an intraocular shunt being deployed
within the eye, according to yet another embodiment.
[0078] FIGS. 54A-54E depict an intraocular shunt being deployed
within the eye, according to yet another embodiment.
DETAILED DESCRIPTION
[0079] In the following detailed description, numerous specific
details are set forth to provide a full understanding of the
subject technology. It should be understood that the subject
technology may be practiced without some of these specific details.
In other instances, well-known structures and techniques have not
been shown in detail so as not to obscure the subject
technology.
[0080] Further, while the present description sets forth specific
details of various embodiments, it will be appreciated that the
description is illustrative only and should not be construed in any
way as limiting. Additionally, it is contemplated that although
some embodiments may be disclosed or shown in the context of ab
interno procedures, such embodiments can be used in ab externo
procedures. Furthermore, various applications of such embodiments
and modifications thereto, which may occur to those who are skilled
in the art, are also encompassed by the general concepts described
herein.
[0081] Glaucoma is a disease in which the optic nerve is damaged,
leading to progressive, irreversible loss of vision. It is
typically associated with increased pressure of the fluid (i.e.,
aqueous humor) in the eye. Untreated glaucoma leads to permanent
damage of the optic nerve and resultant visual field loss, which
can progress to blindness. Once lost, this damaged visual field
cannot be recovered.
[0082] 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.
[0083] 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 drainage 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, through the trabecular meshwork and
sclera).
[0084] 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 deep to 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 deep to the
conjunctiva 7 through a venous drainage system (not shown).
[0085] FIG. 2 is an enlarged view of the schematic diagram of FIG.
1 taken along section lines 2-2. FIG. 2 illustrates a detail view
of the sclera 8 and surrounding tissue. As shown, the conjunctiva 7
attaches to the sclera 8 at the limbus 9.
[0086] Deep to the conjunctiva 7 is Tenon's capsule 10, sometimes
referred to as Tenon's membrane or Tenon's tendon. Tenon's capsule
10 comprises two layers (i.e., superficial and deep layers) and an
intra-Tenon's adhesion space 10 that extends between the
superficial and deep layers of Tenon's capsule 10. The
intra-Tenon's adhesion space 11 surrounds the eye
circumferentially. The intra-Tenon's adhesion space 11 can extend
around the eye posterior to the limbus 9.
[0087] In the view of FIG. 2, deep to the intra-Tenon's adhesion
space 11 is a rectus muscle 20. The eye has four rectus muscles
(superior, inferior, lateral, and medial) that attach to sclera via
a rectus tendon. FIG. 2 illustrates that the rectus muscle 20
attaches to the sclera 8 via a rectus tendon 22. For illustration
purposes, the rectus tendon 22 is shown inserting onto the sclera
8. In some cases, there may not be a clear insertion point of the
rectus tendon 22 onto the sclera 8, but there will be a gradual
transition between the rectus tendon 22 and the intra-Tenon's
adhesion space 11.
[0088] Additionally, as illustrated in FIG. 1, Tenon's capsule 10
and the intra-Tenon's adhesion space 11 is illustrated extending
anteriorly relative to and superficial to the rectus muscle 20. As
also shown, posterior to the rectus tendon, Tenon's capsule 10 and
the intra-Tenon's adhesion space 11 also extend deep to and around
the rectus muscle 20. In this region, there is a reflection of
Tenon's capsule 10 and the intra-Tenon's adhesion space 11 from the
rectus muscle 20 onto the globe or sclera 8. Thus, Tenon's capsule
10 and the intra-Tenon's adhesion space 11 envelop or encapsulate
the rectus muscle 20.
[0089] FIG. 2 illustrates that in some locations, Tenon's capsule
10, and thus, the intra-Tenon's adhesion space 11, surrounds a
rectus muscle 20. According to some embodiments of the methods
disclosed herein, the intra-Tenon's adhesion space 11 can be
accessed from the anterior chamber 1. Tenon's capsule 10 and the
intra-Tenon's adhesion space 11 surround the eye
circumferentially.
[0090] FIG. 2 also illustrates the drainage channels of the eye,
including Schlemm's canal 30 and the trabecular meshwork 32, which
extend through the sclera 8. Further, deep to the sclera 8, the
ciliary body 34 is also shown. The ciliary body 34 transitions
posteriorly to the choroid 40. Deep to the limbus 9 is a scleral
spur 36. The scleral spur 36 extends circumferentially within the
anterior chamber 1 of the eye. Further, the scleral spur 36 is
disposed anteriorly to the anterior chamber angle 38. Furthermore,
"anterior chamber angle tissue" can refer to the eye tissue in the
region extending along and/or including one or more of the cornea
2, the sclera 8, Schlemm's canal 30, the trabecular meshwork 32,
the ciliary body 34, the iris 35, or the scleral spur 36.
[0091] Accordingly, for definitional purposes, the space between
the conjunctiva 7 and Tenon's capsule or the intra-Tenon's adhesion
space 11 is referred to herein as subconjunctival space 332 (here
shown as a potential space). Further, the space within a deep layer
360 and a superficial layer 370 of Tenon's capsule 10 is referred
to herein as the intra-Tenon's adhesion space 11. Additionally, the
space within the sclera 8 (i.e., between the superficial and deep
layers of the sclera 8) is referred to herein as intrascleral space
342 (here shown as a potential space). The space between the sclera
8 and the ciliary body 34 is referred to herein as supraciliary
space 310 (here shown as a potential space). Finally, the space
between the sclera 8 and the choroid 40 is referred to as
suprachoroidal space 322 (here shown as a potential space). The
supraciliary space 310 can be continuous with the suprachoroidal
space 322.
[0092] Ab interno approaches for implanting an intraocular shunt in
the subconjunctival space are shown for example in Yu et al. (U.S.
Pat. No. 6,544,249 and U.S. Patent Publication 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 deployment device 115 that
holds an intraocular shunt, and deploying the shunt within the eye
116. A deployment device 115 holding the shunt enters the eye 116
through the cornea 117 (ab interno approach). The deployment device
115 is advanced across the anterior chamber 120 (as depicted by the
broken line) in what is referred to as a transpupil implant
insertion. The deployment device 115 is advanced through the sclera
121 until a distal portion of the device is in proximity to the
subconjunctival space 118 deep to the conjunctiva 119. 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.
[0093] While such ab interno subconjunctival filtration procedures
have been successful in relieving intraocular pressure, there is a
substantial risk that the intraocular shunt may be deployed too
close to the conjunctiva, resulting in irritation and subsequent
inflammation and/or scarring of the conjunctiva, which can cause
the glaucoma filtration procedure to fail (See Yu et al., Progress
in Retinal and Eye Research, 28:303-325 (2009)). Additionally,
commercially available shunts that are currently utilized in such
procedures are not ideal for ab interno subconjunctival placement
due to the length of the shunt (i.e., too long) and/or the
materials used to make the shunt (e.g., gold, polymer, titanium, or
stainless steel), and can cause significant irritation to the
tissue surrounding the shunt, as well as the conjunctiva, if
deployed too close.
[0094] The present disclosure provides methods for implanting
intraocular shunts within the sclera (i.e., intrascleral
implantation) and are thus suitable for use in an glaucoma
filtration procedure (ab interno or ab externo). In some
embodiments of the methods disclosed herein, the implanted shunt
forms a passage from the anterior chamber of the eye into the
sclera (i.e., intrascleral space). Design and/or deployment of an
intraocular shunt such that the inlet terminates in the anterior
chamber and the outlet terminates intrascleral safeguard the
integrity of the conjunctiva to allow subconjunctival drainage
pathways to successfully form. Additionally, drainage into the
intrascleral space provides access to more lymphatic channels than
just the conjunctival lymphatic system, such as the episcleral
lymphatic network.
[0095] Additionally, some embodiments of the methods disclosed
herein recognize that while intrascleral shunt placement avoids
contact with the conjunctiva, fluid outflow from the shunt into the
intrascleral space may overwhelm the natural drainage structures
(e.g., the episcleral vessel complex) proximate the intrascleral
space. According to some embodiments, the present disclosure can
combine intrascleral shunt placement with creation of a passageway
through the sclera, thereby facilitating fluid drainage from the
intrascleral space. Such a passageway facilitates diffusion of
fluid into the subconjunctival and suprachoroidal spaces.
Accordingly, the advantages of intrascleral shunt placement are
recognized and the additional drainage passageway prevents the
natural drainage structures proximate the intrascleral space from
becoming overwhelmed with fluid output from the shunt.
Embodiments of Intraocular Shunts
[0096] According to some embodiments, the present disclosure
provides intraocular shunts that are configured to form a drainage
pathway from the anterior chamber of the eye to the intrascleral
space. In particular, according to some embodiments, the
intraocular shunts have a length that is sufficient to form a
drainage pathway from the anterior chamber of the eye to the
intrascleral space. The length of the shunt is important for
achieving placement specifically in the intrascleral space. A shunt
that is too long will extend beyond the intrascleral 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.
[0097] According to some embodiments, shunts used in methods
disclosed herein may be any length that allows for drainage of
aqueous humor from an anterior chamber of an eye to the
intrascleral space. Exemplary shunts range in length from about 1
mm to about 10 mm or between about 2 mm to about 6 mm, or any
specific value within said ranges. In certain embodiments, the
length of the shunt is between about 2 mm to about 4 mm, or any
specific value within said range. According to some embodiments,
the intraocular shunts disclosed herein can be 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.
Some embodiments of the methods disclosed herein may be conducted
using any commercially available shunts, such as the Optonol
Ex-PRESS.TM. mini Glaucoma shunt, and the Solx DeepLight Gold.TM.
Micro-Shunt.
[0098] In some embodiments, the intraocular shunts disclosed herein
can be flexible, and have an elasticity modulus that is
substantially identical to the elasticity modulus of the
surrounding tissue in the implant site. As such, some embodiments
of the intraocular shunts disclosed herein can be 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, some embodiments
of the intraocular shunts disclosed herein do not induce
substantial ocular inflammation such as subconjunctival blebbing or
endophthalmitis. Additional exemplary features of some embodiments
of intraocular shunts are discussed in further detail below.
Tissue Compatible Shunts
[0099] In certain aspects, the present disclosure generally
provides 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
shunts can be 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.
[0100] 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.
[0101] 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.
[0102] 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.
[0103] Some embodiments of the shunts can be 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.
[0104] In some embodiments, the shunt can be 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 about
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.
[0105] The present disclosure encompasses shunts of different
shapes and different dimensions, and some embodiments of the shunts
disclosed herein 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
about 10 .mu.m to about 250 .mu.m, an outside diameter from about
100 .mu.m to about 450 .mu.m, and a length from about 2 mm to about
10 mm.
Shunts Reactive to Pressure
[0106] In other aspects, the present disclosure generally provides
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. 5 provides a
schematic of a shunt 123 having a flexible portion 151. In this
figure, the flexible portion 151 is shown in the middle of the
shunt 123. However, the flexible portion 151 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.
[0107] The flexible portion 151 of the shunt 123 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 about 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 mmHg to about 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).
[0108] 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. = dV dT = v .times. .pi. .times. R 2 = .pi. .times. R 4 8
.times. .eta. .times. ( - .DELTA. .times. P .DELTA. .times. x ) =
.pi. .times. R 4 8 .times. .eta. .times. "\[LeftBracketingBar]"
.DELTA. .times. P "\[RightBracketingBar]" L ##EQU00002##
[0109] where .PHI. is the volumetric flow rate; V is a volume of
the liquid poured (cubic meters); t is the time (seconds); v 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).
[0110] FIG. 6A provides a schematic of a shunt 126 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 intrascleral
space). The shunt is implanted such that a proximal end 127 of the
shunt 126 resides in the anterior chamber 128 of the eye, and a
distal end 129 of the shunt 126 resides outside of the anterior
chamber to conduct aqueous humor from the anterior chamber to an
area of lower pressure. A flexible portion 130 of the shunt 126
spans at least a portion of the sclera of the eye. As shown in FIG.
6A, the flexible portion spans an entire length of the sclera
131.
[0111] When the pressure exerted on the flexible portion 130 of the
shunt 126 by sclera 131 (vertical arrows) is greater than the
pressure exerted on the flexible portion 130 of the shunt 126 by
the fluid flowing through the shunt (horizontal arrow), the
flexible portion 130 decreases in diameter, restricting flow
through the shunt 126 (FIG. 6B). The restricted flow results in
aqueous humor leaving the anterior chamber 128 at a reduced
rate.
[0112] When the pressure exerted on the flexible portion 130 of the
shunt 126 by the fluid flowing through the shunt (horizontal arrow)
is greater than the pressure exerted on the flexible portion 130 of
the shunt 126 by the sclera 131 (vertical arrows), the flexible
portion 130 increases in diameter, increasing flow through the
shunt 126 (FIG. 6C). The increased flow results in aqueous humor
leaving the anterior chamber 128 at an increased rate.
[0113] The present disclosure encompasses shunts of different
shapes and different dimensions, and some embodiments of the shunts
disclosed herein 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
about 10 .mu.m to about 250 .mu.m, an outside diameter from about
100 .mu.m to about 450 .mu.m, and a length from about 2 mm to about
10 mm.
[0114] In some 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.
[0115] It will be appreciated that different dimensioned implants
may be used. For example, shunts that range in length 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 about 0.5
mmHg to about 20 mmHg.
[0116] 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.
[0117] 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 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.
[0118] 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 some embodiments, 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.
[0119] In one embodiment, the gelatin is contacted with a solution
of about 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 about 7 to about
7.8 and, more particularly, about 7.35 to about 7.44 and typically
about 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.
[0120] Methods for forming the flexible portion of the shunt are
shown for example in Yu et al. (U.S. patent application number
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 about
55.degree. C. with thorough mixing to ensure complete dissolution
of the gelatin. In one embodiment, the ratio of solid gelatin to
water is about 10% to about 50% gelatin by weight to about 50% to
about 90% by weight of water. In an embodiment, the gelatin
solution includes about 40% by weight, gelatin dissolved in water.
The resulting gelatin solution should be devoid of air bubbles and
has a viscosity that is between about 200 centipoise ("cp") to
about 500 cp and more particularly between about 260 cp and about
410 cp.
[0121] 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.
[0122] 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, about 10 hours to about 24 hours.
Apparatus for forming gelatin tubes are described in Yu et al.
(U.S. patent application number 2008/0108933).
[0123] 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 from about 7.0 to
about 7.8 and more preferably from about 7.35 to about 7.44 at room
temperature for at least about 4 hours and preferably from about 10
to about 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 glutaraldehyde for at
least about 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.
[0124] 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 from about 3 days to about 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 from about 48 to about 96 hours
and more typically 3 days (i.e., 72 hours) may be preferred for the
formation of the cross-linked gelatin tubes.
[0125] 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.
[0126] 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
[0127] Other aspects of the present disclosure 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 drainage structures associated with the intrascleral
space.
[0128] The shunt may have many different configurations. FIG. 7A
shows an embodiment of a shunt 132 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 133a
to 133e) and the distal portion of the shunt (i.e., the portion
that is located in the intrascleral space) includes a single port
134. FIG. 7B shows another embodiment of a shunt 132 in which the
proximal portion includes a single port 133 and the distal portion
includes more than one port (designated as numbers 134a to 134e).
FIG. 7C shows another embodiment of a shunt 132 in which the
proximal portions include more than one port (designated as numbers
133a to 133e) and the distal portions include more than one port
(designated as numbers 134a to 134e). While FIGS. 7A-7C show shunts
having 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
shunts disclosed herein include all shunts having more than two
ports. For example, some embodiments of the shunts disclosed herein
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.
[0129] 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. 7A, which depicts ports 133a, 133b, 133d, and
133e as being oriented at a 90.degree. angle to port 133c.
[0130] 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. 8A and 8B show an embodiment of a shunt 132 having
multiple ports (133a and 133b) at a proximal end and a single port
134 at a distal end. FIG. 8A shows that port 133b has an inner
diameter that is different from the inner diameters of ports 133a
and 134. In this figure, the inner diameter of port 133b is less
than the inner diameter of ports 133a and 134. An exemplary inner
diameter of port 133b is from about 20 .mu.m to about 40 .mu.m,
particularly about 30 .mu.m. In other embodiments, the inner
diameter of port 133b is greater than the inner diameter of ports
133a and 134. See, for example, FIG. 8B.
[0131] The present disclosure encompasses shunts of different
shapes and different dimensions, and the some embodiments of the
shunts disclosed herein 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
about 10 .mu.m to about 250 .mu.m, an outside diameter from about
100 .mu.m to about 450 .mu.m, and a length from about 0.5 mm to
about 20 mm. Some embodiments of the shunts disclosed herein 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
[0132] Other aspects of the present disclosure 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.
[0133] 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 intrascleral space, the body further including at least one
slit. The slit may be located at any place along the body of the
shunt. FIG. 9A shows a shunt 135 having an inlet 136, an outlet
137, and a slit 138 located in proximity to the inlet 136. FIG. 9B
shows a shunt 135 having an inlet 136, an outlet 137, and a slit
139 located in proximity to the outlet 137. FIG. 9C shows a shunt
135 having an inlet 136, an outlet 137, a slit 138 located in
proximity to the inlet 136, and a slit 139 located in proximity to
the outlet 137.
[0134] While FIGS. 9A-9C 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 shunts disclosed herein
include shunts having more than one overflow port. In certain
embodiments, some embodiments of the shunts disclosed herein
include more than one overflow port at the proximal portion, the
distal portion, or both. For example, FIG. 10 shows a shunt 140
having an inlet 141, an outlet 142, and slits 143a and 143b located
in proximity to the inlet 141. Some embodiments of the shunts
disclosed herein 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 shunts disclosed herein include two slits that
overlap and are oriented at 90.degree. to each other, thereby
forming a cross.
[0135] 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. 11 shows an embodiment of a
shunt 144 having an inlet 145, outlet 146, and a slit 147 that is
located at the proximal end of the shunt, producing a split in the
inlet 145 of the shunt.
[0136] 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.
[0137] The present disclosure encompasses shunts of different
shapes and different dimensions, and some embodiments of the shunts
disclosed herein 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
about 10 .mu.m to about 250 .mu.m, an outside diameter from about
100 .mu.m to about 450 .mu.m, and a length from about 2 mm to about
10 mm. Some embodiments of the shunts disclosed herein 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
[0138] In other aspects, the present disclosure generally provides
a shunt having a variable inner diameter. In some 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.
[0139] FIG. 12 shows an embodiment of a shunt 148 having an inlet
149 configured to receive fluid from an anterior chamber of an eye
and an outlet 150 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 149 to the outlet 150.
In certain embodiments, the inner diameter continuously increases
along the length of the body, for example as shown in FIG. 12. In
other embodiments, the inner diameter remains constant along
portions of the length of the body.
[0140] 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. The present disclosure encompasses shunts of different
shapes and different dimensions, and some embodiments of the shunts
disclosed herein 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
about 10 .mu.m to about 250 .mu.m, an outside diameter from about
100 .mu.m to about 450 .mu.m, and a length from about 2 mm to about
10 mm. Shunts of the invention 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
[0141] In other aspects, the present disclosure generally provides
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.
[0142] FIGS. 13A-13D show embodiments of a shunt 152 in which at
least one end of the shunt 152 includes a plurality of prongs
153a-153d. FIGS. 13A-13D 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.
[0143] Prongs 153a-153d can have any shape (i.e., width, length,
height). FIGS. 13A-13B show prongs 153a-153d as straight prongs. In
this embodiment, the spacing between the prongs 153a-153d is the
same. In another embodiment shown in FIGS. 13C-13D, prongs
153a-153d are tapered. In this embodiment, the spacing between the
prongs increases toward a proximal and/or distal end of the shunt
152.
[0144] FIGS. 13A-13D show embodiments that include four prongs.
However, some embodiments of the shunts disclosed herein 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.
[0145] The present disclosure encompasses shunts of different
shapes and different dimensions, and some embodiments of the shunts
disclosed herein 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
about 10 .mu.m to about 250 .mu.m, an outside diameter from about
100 .mu.m to about 450 .mu.m, and a length from about 2 mm to about
10 mm. Some embodiments of the shunts disclosed herein 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
[0146] In other aspects, the present disclosure generally provides
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.
[0147] FIGS. 14A-14D show embodiments of a shunt 154 in which at
least one end of the shunt 154 includes a longitudinal slit 155
that produces a top portion 156a and a bottom portion 156b in a
proximal and/or distal end of the shunt 154. FIGS. 14A-14D show an
embodiment in which both a proximal end and a distal end include a
longitudinal slit 155 that produces a top portion 156a and a bottom
portion 156b in both ends of the shunt 154. However, numerous
different configurations are envisioned. For example, in certain
embodiments, only the proximal end of the shunt includes
longitudinal slit 155. In other embodiments, only the distal end of
the shunt includes longitudinal slit 155.
[0148] Longitudinal slit 155 can have any shape (i.e., width,
length, height). FIGS. 14A-14B show a longitudinal slit 155 that is
straight such that the space between the top portion 156a and the
bottom portion 156b remains the same along the length of the slit
155. In another embodiment shown in FIGS. 14C-14D, longitudinal
slit 155 is tapered. In this embodiment, the space between the top
portion 145a and the bottom portion 156b increases toward a
proximal and/or distal end of the shunt 154.
[0149] The present disclosure encompasses shunts of different
shapes and different dimensions, and the some embodiments of the
shunts disclosed herein 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
about 10 .mu.m to about 250 .mu.m, an outside diameter from about
100 .mu.m to about 450 .mu.m, and a length from about 2 mm to about
10 mm. Some embodiments of the shunts disclosed herein may be made
from any biocompatible material. An exemplary material is gelatin.
Methods of making shunts composed of gelatin are described
above.
Pharmaceutical Agents
[0150] In certain embodiments, some embodiments of the shunts
disclosed herein 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.
Patent App. No. 2008/0108933). The content of each of these
references is incorporated by reference herein its entirety.
[0151] 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 intrascleral
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 intrascleral
space).
[0152] Any pharmaceutical and/or biological agent or combination
thereof may be used with some embodiments of the shunts disclosed
herein. 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 Lucentis,
Macugen, Avastin, VEGF or steroids).
Deployment Devices
[0153] Any deployment device or system known in the art may be used
with some embodiments of the methods disclosed herein. In certain
embodiments, deployment into the eye of an intraocular shunt
according to some embodiments 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 deploying
shunts according to some embodiments include, but are not limited
to the deployment devices described in U.S. Pat. Nos. 6,007,511,
6,544,249, U.S. Publication No. 2008/0108933, U.S. Patent App. No.
61/904,429, filed on Nov. 14, 2013, and U.S. patent application
Ser. No. 14/313,970, filed on Jun. 24, 2013, the contents of which
are each incorporated herein 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, or deployment devices described
in co-pending and co-owned U.S. patent application Ser. No.
12/946,645 filed on Nov. 15, 2010, the entire content of each of
which is incorporated by reference herein.
[0154] A shunt deployment device, such as those disclosed herein,
can be used to implant the shunt in accordance with a variety of
potential procedures, which can be modified or updated, according
to aspects of the disclosure herein, as well as future
methodologies and device features. For example, as discussed and
shown below with regard to FIGS. 52A-54E, a shunt deployment device
can be used to implant a shunt using a variety of different
procedures. The deployment device can be manual or automatic and
can include features of one or more of the devices discussed or
mentioned herein.
[0155] For example, in some embodiments, the shunts can be deployed
into the eye using the deployment device 200 depicted in FIG. 15.
While FIG. 15 shows a handheld, manually operated shunt deployment
device, it will be appreciated that devices according to some
embodiments may be coupled with robotic systems and may be
completely or partially automated. As shown in FIG. 15, deployment
device 200 includes a generally cylindrical body or housing 201;
however, the body shape of housing 201 could be other than
cylindrical. Housing 201 may have an ergonomical shape, allowing
for comfortable grasping by an operator. Housing 201 is shown with
optional grooves 202 to allow for easier gripping by a surgeon.
[0156] According to some embodiments, the shunt can be advanced
into the eye tissue at a rate of between about 0.15 mm/sec to about
0.85 mm/sec. Further, in some embodiments, the shunt can be
advanced into the eye tissue at a rate of between about 0.25 mm/sec
to about 0.65 mm/sec.
[0157] Housing 201 is shown having a larger proximal portion that
tapers to a distal portion. The distal portion includes a hollow
sleeve 205. The hollow sleeve 205 is configured for insertion into
an eye and to extend into an anterior chamber of an eye. The hollow
sleeve 205 is visible within an anterior chamber of an eye.
According to some embodiment, the sleeve 205 can provide a visual
preview or guide for an operator as to placement of the proximal
portion of the shunt within the anterior chamber of an eye, as
discussed below with regard to FIGS. 52A-52E. The sleeve 205 can
provide a visual reference point that may be used by an operator to
hold device 100 steady during the shunt deployment process, thereby
assuring optimal longitudinal placement of the shunt within the
eye.
[0158] According to some embodiments, the sleeve 205 may also
include an edge 231 at a distal end that provides resistance
feedback to an operator upon insertion of the deployment device 200
within an eye 232 of a person during delivery of the shunt 215, as
discussed below with regard to FIGS. 53A-54E. Upon advancement of
the device 200 across an anterior chamber 233 of the eye 232, the
hollow sleeve 205 will eventually contact the anterior chamber
angle tissue, and may abut sclera 234, providing resistance
feedback to an operator that no further advancement of the device
200 is necessary. A temporary guard 208 is configured to fit around
sleeve 205 and extend beyond an end of sleeve 205. The edge 231 of
the sleeve 205 prevents the shaft 204 from accidentally being
pushed too far through the sclera 234. The guard is used during
shipping of the device and protects an operator from a distal end
of a hollow shaft 204 that extends beyond the end of the sleeve
205. The guard is removed prior to use of the device.
[0159] Housing 201 is open at its proximal end, such that a portion
of a deployment mechanism 203 may extend from the proximal end of
the housing 201. A distal end of housing 201 is also open such that
at least a portion of a hollow shaft 204 may extend through and
beyond the distal end of the housing 201. Housing 201 further
includes a slot 206 through which an operator, such as a surgeon,
using the device 200 may view an indicator 207 on the deployment
mechanism 203.
[0160] Housing 201 may be made of any material that is suitable for
use in medical devices. For example, housing 201 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 201 is made of a material that may be autoclaved, and thus
allow for housing 201 to be re-usable. Alternatively, device 200
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.
[0161] Housing 201 may be made of multiple components that connect
together to form the housing. FIG. 16 shows an exploded view of
deployment device 200. In this figure, housing 201 is shown having
three components 201a, 201b, and 201c. The components are designed
to screw together to form housing 201. FIGS. 17A-17D also show
deployment mechanism 203. The housing 201 is designed such that
deployment mechanism 203 fits within assembled housing 201. Housing
201 is designed such that components of deployment mechanism 203
are movable within housing 201.
[0162] FIGS. 17A-17D show different enlarged views of the
deployment mechanism 203. Deployment mechanism 203 may be made of
any material that is suitable for use in medical devices. For
example, deployment mechanism 203 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 203 is made of a material that may be
autoclaved, and thus allow for deployment mechanism 203 to be
re-usable. Alternatively, device 200 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.
[0163] Deployment mechanism 203 includes a distal portion 209 and a
distal portion 210. The deployment mechanism 203 is configured such
that distal portion 209 is movable within distal portion 210. More
particularly, distal portion 209 is capable of partially retracting
to within proximal portion 210.
[0164] In this embodiment, the distal portion 209 is shown to taper
to a connection with a hollow shaft 204. This embodiment is
illustrated such that the connection between the hollow shaft 204
and the distal portion 209 of the deployment mechanism 203 occurs
inside the housing 201. In other embodiments, the connection
between hollow shaft 204 and the distal portion 209 of the
deployment mechanism 203 may occur outside of the housing 201.
Hollow shaft 204 may be removable from the distal portion 209 of
the deployment mechanism 203. Alternatively, the hollow shaft 204
may be permanently coupled to the distal portion 209 of the
deployment mechanism 203.
[0165] Generally, hollow shaft 204 is configured to hold an
intraocular shunt, such as the intraocular shunts according to some
embodiments. The shaft 204 may be any length. A usable length of
the shaft may be anywhere from about 5 mm to about 40 mm, and is
about 15 mm in certain embodiments. In certain embodiments, the
shaft is straight. In other embodiments, shaft is of a shape other
than straight, for example a shaft having a bend along its
length.
[0166] A proximal portion of the deployment mechanism includes
optional grooves 216 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 210 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. 17A and 17C show a deployment mechanism
having two indicators, a ready indicator 211 and a deployed
indicator 219. Ready indicator 211 provides feedback to an operator
that the deployment mechanism is in a configuration for deployment
of an intraocular shunt from the deployment device 200. The ready
indicator 211 is shown in this embodiment as a green oval having a
triangle within the oval. Deployed indicator 219 provides feedback
to the operator that the deployment mechanism has been fully
engaged and has deployed the shunt from the deployment device 200.
The deployed indicator 219 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 211 and 219 may be seen through slot 206 in housing
201.
[0167] The proximal portion 210 includes a stationary portion 210b
and a rotating portion 210a. The proximal portion 210 includes a
channel 212 that runs part of the length of stationary portion 210b
and the entire length of rotating portion 210a. The channel 212 is
configured to interact with a protrusion 217 on an interior portion
of housing component 201a (FIGS. 18A and 18B). During assembly, the
protrusion 217 on housing component 201a is aligned with channel
212 on the stationary portion 210b and rotating portion 210a of the
deployment mechanism 203. The proximal portion 210 of deployment
mechanism 203 is slid within housing component 201 a until the
protrusion 217 sits within stationary portion 210b (FIG. 18C).
Assembled, the protrusion 217 interacts with the stationary portion
210b of the deployment mechanism 203 and prevents rotation of
stationary portion 210b. In this configuration, rotating portion
210a is free to rotate within housing component 201a.
[0168] Referring back to FIGS. 17A-17D, the rotating portion 210a
of proximal portion 210 of deployment mechanism 203 also includes
channels 213a, 213b, and 213c. Channel 213a includes a first
portion 213a1 that is straight and runs perpendicular to the length
of the rotating portion 210a, and a second portion 213a2 that runs
diagonally along the length of rotating portion 210a, downwardly
toward a proximal end of the deployment mechanism 203. Channel 213b
includes a first portion 213b1 that runs diagonally along the
length of the rotating portion 210a, downwardly toward a distal end
of the deployment mechanism 203, and a second portion that is
straight and runs perpendicular to the length of the rotating
portion 210a. The point at which first portion 213a1 transitions to
second portion 213a2 along channel 213a, is the same as the point
at which first portion 213b1 transitions to second portion 213b2
along channel 213b. Channel 213c is straight and runs perpendicular
to the length of the rotating portion 210a. Within each of channels
213a, 213b, and 213c, sit members 214a, 214b, and 214c
respectively. Members 214a, 214b, and 214c are movable within
channels 213a, 213b, and 213c. Members 214a, 214b, and 214c also
act as stoppers that limit movement of rotating portion 210a, which
thereby limits axial movement of the shaft 204.
[0169] FIG. 19 shows a cross-sectional view of deployment mechanism
203. Member 214a is connected to the distal portion 209 of the
deployment mechanism 203. Movement of member 214a results in
retraction of the distal portion 209 of the deployment mechanism
203 to within the proximal portion 210 of the deployment mechanism
203. Member 214b is connected to a pusher component 218. The pusher
component 218 extends through the distal portion 209 of the
deployment mechanism 203 and extends into a portion of hollow shaft
204. The pusher component is involved in deployment of a shunt from
the hollow shaft 204. An exemplary pusher component is a plunger.
Movement of member 214b engages pusher 218 and results in pusher
218 advancing within hollow shaft 204.
[0170] Reference is now made to FIGS. 20A-22D, which accompany the
following discussion regarding deployment of a shunt 215 from
deployment device 200. FIG. 20A shows deployment device 200 in a
pre-deployment configuration. In this configuration, shunt 215 is
loaded within hollow shaft 204 (FIG. 20C). As shown in FIG. 20C,
shunt 215 is only partially within shaft 204, such that a portion
of the shunt is exposed. However, the shunt 215 does not extend
beyond the end of the shaft 204. In other embodiments, the shunt
215 is completely disposed within hollow shaft 204. The shunt 215
is loaded into hollow shaft 204 such that the shunt abuts pusher
component 218 within hollow shaft 204. A distal end of shaft 204 is
beveled to assist in piercing tissue of the eye.
[0171] Additionally, in the pre-deployment configuration, a portion
of the shaft 204 extends beyond the sleeve 205 (FIG. 20C). The
deployment mechanism is configured such that member 214a abuts a
distal end of the first portion 213a1 of channel 213a, and member
214b abuts a proximal end of the first portion 213b1 of channel
213b (FIG. 20B). In this configuration, the ready indicator 211 is
visible through slot 206 of the housing 201, providing feedback to
an operator that the deployment mechanism is in a configuration for
deployment of an intraocular shunt from the deployment device 200
(FIG. 20A). In this configuration, the device 200 is ready for
insertion into an eye (insertion configuration or pre-deployment
configuration). Methods for inserting and implanting shunts are
discussed in further detail below.
[0172] Once the device has been inserted into the eye and advanced
to a location to where the shunt will be deployed, the shunt 215
may be deployed from the device 200. The deployment mechanism 203
is a two-stage system. The first stage is engagement of the pusher
component 218 and the second stage is retraction of the distal
portion 209 to within the proximal portion 210 of the deployment
mechanism 203. Rotation of the rotating portion 210a of the
proximal portion 210 of the deployment mechanism 203 sequentially
engages the pusher component and then the retraction component.
[0173] 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 210a of
the proximal portion 210 of the deployment mechanism 203 is
rotated, resulting in movement of members 214a and 214b along first
portions 213a1 and 213b1 in channels 213a and 213b. Since the first
portion 213a1 of channel 213a is straight and runs perpendicular to
the length of the rotating portion 210a, rotation of rotating
portion 210a does not cause axial movement of member 214a. Without
axial movement of member 214a, there is no retraction of the distal
portion 209 to within the proximal portion 210 of the deployment
mechanism 203. Since the first portion 213b1 of channel 213b runs
diagonally along the length of the rotating portion 210a, upwardly
toward a distal end of the deployment mechanism 203, rotation of
rotating portion 210a causes axial movement of member 214b toward a
distal end of the device. Axial movement of member 214b toward a
distal end of the device results in forward advancement of the
pusher component 218 within the hollow shaft 204. Such movement of
pusher component 218 results in partial deployment of the shunt 215
from the shaft 204.
[0174] FIGS. 21A-21C show schematics of the deployment mechanism at
the end of the first stage of deployment of the shunt from the
deployment device. As is shown FIG. 21A, members 214a and 214b have
finished traversing along first portions 213a1 and 213b1 of
channels 213a and 213b. Additionally, pusher component 218 has
advanced within hollow shaft 204 (FIG. 21B), and shunt 215 has been
partially deployed from the hollow shaft 204 (FIG. 21C). As is
shown in these figures, a portion of the shunt 215 extends beyond
an end of the shaft 204.
[0175] In the second stage of shunt deployment, the retraction
component 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 210a of the proximal portion 210 of the deployment
mechanism 203 is further rotated, resulting in movement of members
214a and 214b along second portions 213a2 and 213b2 in channels
213a and 213b. Since the second portion 213b2 of channel 213b is
straight and runs perpendicular to the length of the rotating
portion 210a, rotation of rotating portion 210a does not cause
axial movement of member 214b. Without axial movement of member
214b, there is no further advancement of pusher component 218.
Since the second portion 213a2 of channel 213a runs diagonally
along the length of the rotating portion 210a, downwardly toward a
proximal end of the deployment mechanism 203, rotation of rotating
portion 210a causes axial movement of member 214a toward a proximal
end of the device. Axial movement of member 214a toward a proximal
end of the device results in retraction of the distal portion 209
to within the proximal portion 210 of the deployment mechanism 203.
Retraction of the distal portion 209, results in retraction of the
hollow shaft 204. Since the shunt 215 abuts the pusher component
218, the shunt remains stationary as the hollow shaft 204 retracts
from around the shunt 215 (FIG. 21C). The shaft 204 retracts almost
completely to within the sleeve 205. During both stages of the
deployment process, the sleeve 205 remains stationary and in a
fixed position.
[0176] FIGS. 22A-22D show schematics of the device 200 after
deployment of the shunt 215 from the device 200. FIG. 22B shows a
schematic 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. 22B, members 214a and 214b have finished traversing
along second portions 213a1 and 213b1 of channels 213a and 213b.
Additionally, distal portion 209 has retracted to within proximal
portion 210, thus resulting in retraction of the hollow shaft 204
to within the sleeve 205. FIG. 22D shows an enlarged view of the
distal portion of the deployment device after deployment of the
shunt. This figure shows that the hollow shaft 204 is not fully
retracted to within the sleeve 205 of the deployment device 200.
However, in certain embodiments, the shaft 204 may completely
retract to within the sleeve 205.
Methods for Intrascleral Shunt Placement
[0177] Some embodiments of the methods disclosed herein can involve
creating an opening in the sclera (e.g., by piercing the sclera
with a delivery device), and positioning a shunt in the anterior
chamber of the eye such that the shunt terminates adjacent an
opening formed in the sclera. In some embodiments, such placement
can permit flow through the shunt to reach the intrascleral space,
thereby facilitating fluid flow through both the opening and the
intrascleral space. The outlet of the shunt may be positioned in
different places within the intrascleral space. For example, the
outlet of the shunt may be positioned within the sclera (e.g.,
within deep and superficial layers or tissue of the sclera).
Alternatively, the outlet of the shunt may be positioned such that
the outlet is even with or superficial to the opening through the
sclera.
[0178] 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, through the trabecular meshwork and sclera). The
deployment device may be any device that is suitable for implanting
an intraocular shunt into an eye. Such devices generally include a
shaft connected to a deployment mechanism. In some devices, a shunt
is positioned over an exterior of the shaft and the deployment
mechanism works to deploy the shunt from an exterior of the shaft.
In other devices, the shaft is hollow and the shunt is at least
partially disposed in the shaft. In those devices, the deployment
mechanism works to deploy the shunt from within the shaft.
Depending on the device, a distal portion of the shaft may be
sharpened or blunt, or straight or curved.
Ab-Interno Approach
[0179] Ab interno approaches for implanting an intraocular shunt in
the subconjunctival space are shown for example in Yu et al. (U.S.
Pat. No. 6,544,249 and U.S. Patent Publication 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. An exemplary
ab-interno method employs a transpupil approach and involves
creating a first opening in the sclera of an eye, advancing a shaft
configured to hold an intraocular shunt across an anterior chamber
of an eye and through the sclera to create a second opening in the
sclera, retracting the shaft through the second opening to within
the sclera (i.e., the intrascleral space), deploying the shunt from
the shaft such that the shunt forms a passage from the anterior
chamber of the eye to the intrascleral space of the eye, such that
an outlet of the shunt is positioned so that at least some of the
fluid that exits the shunt flows through the second opening in the
sclera, and withdrawing the shaft from the eye. The first opening
in the sclera may be made in any manner. In certain embodiments,
the shaft creates the first opening in the sclera. In other
embodiments, a tool other than the shaft creates the first opening
in the sclera.
[0180] In certain embodiments, some embodiments of the methods
disclosed herein can generally 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 into the sclera (i.e., the intrascleral
space). The hollow shaft is then withdrawn from the eye.
[0181] To place the shunt within the eye, a surgical intervention
to implant the shunt is performed that involves inserting into the
eye a deployment device that holds an intraocular shunt, and
deploying at least a portion of the shunt within intrascleral
space. FIGS. 23-30 provide an exemplary sequence for ab interno
shunt placement. In certain embodiments, a hollow shaft 109 of a
deployment device holding the shunt 112 enters the eye through the
cornea (ab interno approach, FIG. 23). The shaft 109 is advanced
across the anterior chamber 110 in what is referred to as a
transpupil implant insertion. The shaft 109 is advanced through the
anterior angle tissues of the eye and into the sclera 8 and further
advanced until it passes through the sclera 8, thereby forming a
second opening in the sclera 8 (FIGS. 24-25). Once the second
opening in the sclera 8 is achieved, the shaft 109 is retracted all
the way back through the sclera 8 and into the anterior chamber 110
of the eye (FIGS. 26-29). During this shaft retraction, the shunt
112 is held in place by a plunger rod 111 that is positioned behind
the proximal end of the shunt 112. After the shaft 109 has been
completely withdrawn from the sclera 8, the plunger rod 111 is
withdrawn as well and the shunt implantation sequence is complete
(FIG. 30). This process results in an implanted shunt 112 in which
a distal end of the shunt 112 is proximate a passageway 114 through
the sclera 8. Once fully deployed, a proximal end of shunt 112
resides in the anterior chamber 110 and a distal end of shunt 112
resides in the intrascleral space. Preferably a sleeve 113 is used
around the shaft 112 and designed in length such that the sleeve
113 acts as a stopper for the scleral penetration of the shaft and
also determines the longitudinal placement of the proximal end of
the shunt.
[0182] Insertion of the shaft of the deployment device into the
sclera 8 produces a long scleral channel of about 2 mm to about 5
mm in length. Withdrawal of the shaft of the deployment device
prior to deployment of the shunt 112 from the device produces a
space in which the shunt 112 may be deployed. Deployment of the
shunt 112 allows for aqueous humor 3 to drain into traditional
fluid drainage channels of the eye (e.g., the intrascleral vein,
the collector channel, Schlemm's canal, the trabecular outflow, and
the uveoscleral outflow to the ciliary muscle. The deployment is
performed such that an outlet of the shunt is positioned proximate
the opening in the sclera so that at least some of the fluid that
exits the shunt flows through the opening in the sclera, thereby
ensuring that the intrascleral space does not become overwhelmed
with fluid output from the shunt.
[0183] FIG. 32 provides an exemplary schematic of a hollow shaft
for use in accordance with some embodiments of the methods
disclosed herein. This figure shows a hollow shaft 122 that is
configured to hold an intraocular shunt 123. The shaft may hold the
shunt within the hollow interior 124 of the shaft, as is shown in
FIG. 32. Alternatively, the hollow shaft may hold the shunt on an
outer surface 125 of the shaft. In some embodiments, the shunt is
held completely within the hollow interior of the shaft 124, as is
shown in FIG. 32. In other embodiments, a shunt 123a is only
partially disposed within a hollow shaft 123b, as shown in FIG. 4.
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 about 10 .mu.m
to about 250 .mu.m, an outside diameter of about 100 .mu.m to about
450 .mu.m, and a length of about 1 mm to about 12 mm. In some
embodiments, the shunt has a length of about 2 mm to about 10 mm
and an outside diameter of about 150 .mu.m to about 400 .mu.m. The
hollow shaft 122 is configured to at least hold a shunt of such
shape and such dimensions. However, the hollow shaft 122 may be
configured to hold shunts of different shapes and different
dimensions than those described above, and some embodiments can
encompass a shaft 122 that may be configured to hold any shaped or
dimensioned intraocular shunt.
[0184] Preferably, some embodiments of the methods disclosed herein
are conducted by making an incision in the eye prior to insertion
of the deployment device. In some embodiments of the methods
disclosed herein may be conducted without making an incision in the
eye prior to insertion of the deployment device. In certain
embodiments, the shaft that is connected to the deployment device
has a sharpened point or tip. In certain embodiments, the hollow
shaft is a needle. Exemplary needles that may be used are
commercially available from Terumo Medical Corp. (Elkington Md.).
In some embodiments, the needle has a hollow interior and a beveled
tip, and the intraocular shunt is held within the hollow interior
of the needle. In another embodiment, the needle has a hollow
interior and a triple ground point or tip.
[0185] Some embodiments of the methods disclosed herein 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
embodiments of the methods disclosed herein are also preferably
conducted without inducing substantial ocular inflammation, such as
subconjunctival blebbing or endophthalmitis. Such methods can be
achieved using an ab interno approach by inserting the hollow shaft
configured to hold the intraocular shunt through the cornea, across
the anterior chamber, through the trabecular meshwork and into the
sclera. However, some embodiments of the methods disclosed herein
may be conducted using an ab externo approach.
[0186] When some embodiments of the methods disclosed herein are
conducted using an ab interno approach, the angle of entry through
the cornea as well as the up and downward forces applied to the
shaft during the scleral penetration affect optimal placement of
the shunt in the intrascleral space. Preferably, the hollow shaft
is inserted into the eye at an angle superficial to the corneal
limbus, in contrast with entering through or deep to the corneal
limbus. For example, the hollow shaft is inserted about 0.25 mm to
about 3.0 mm, preferably about 0.5 mm to about 2.5 mm, more
preferably about 1.0 mm to about 2.0 mm superficial to the corneal
limbus, or any specific value within said ranges, e.g., about 1.0
mm, about 1.1 mm, about 1.2 mm, about 1.3 mm, about 1.4 mm, about
1.5 mm, about 1.6 mm, about 1.7 mm, about 1.8 mm, about 1.9 mm, or
about 2.0 mm superficial to the corneal limbus.
[0187] 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 superficial to the limbus, as well as an S-shaped
scleral tunnel (FIG. 31) due to applied up or downward pressure
during the scleral penetration of the shaft 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.
Ab Externo Approach
[0188] In other embodiments, an ab externo approach is employed. Ab
externo implantation approaches are shown for example in Nissan et
al. (U.S. Pat. No. 8,109,896), Tu et al. (U.S. Pat. No. 8,075,511),
and Haffner et al. (U.S. Pat. No. 7,879,001), the content of each
of which is incorporated by reference herein in its entirety. An
exemplary ab externo approach avoids having to make a scleral flap.
In this preferred embodiment, a distal end of the deployment device
is used to make an opening into the eye and into the sclera. For
example, a needle is inserted from ab externo through the sclera
and exits the anterior angle of the eye. The needle is then
withdrawn, leaving a scleral slit behind. A silicone tube with
sufficient stiffness is then manually pushed through the scleral
slit from the outside so that the distal tube ends distal to the
Trabecular Meshwork in the anterior chamber of the eye. Towards the
proximal end, the tube exits the sclera, lays on top of it, and
connects on its proximal end to a plate that is fixated by sutures
to the outside scleral surface far away (>10 mm) from the
limbus.
[0189] FIGS. 33-39 describes another ab externo method that uses a
deployment device. In this method, a distal portion of the
deployment device includes a hollow shaft 109 that has a sharpened
tip (FIG. 33). A shunt 112 resides within the shaft 109. The distal
shaft 109 is advanced into the eye and into the sclera 8 until a
proximal portion of the shaft resides in the anterior chamber 110
and a distal portion of the shaft 109 is inside the scleral 8
(FIGS. 34-36). Deployment of the shunt 112 that is located inside
the shaft 109 is then accomplished by a mechanism that withdraws
the shaft 109 while the shunt 112 is held in place by a plunger 111
behind the proximal end of the shunt 112 (FIGS. 37-39). As the
implantation sequence progresses, the shaft 109 is completely
withdrawn from the sclera 8. After that, the plunger 111 is
withdrawn from the sclera 8, leaving the shunt 112 behind with its
distal end inside the sclera 8, its proximal end inside the
anterior chamber 110, and a passageway 114 through the sclera 8. In
a preferred embodiment the shaft 109 is placed inside a sleeve 113
that is dimensioned in length relative to the shaft 109 such that
it will act as stopper during the penetration of the shaft 109 into
the eye and at the same time assures controlled longitudinal
placement of the shunt 112 relative to the outer surface of the
eye. The sleeve 113 may be beveled to match the anatomical angle of
the entry site surface.
[0190] The shaft penetrates the conjunctival layer before it enters
and penetrates the sclera. This causes a conjunctival hole that
could create a fluid leakage after the shunt placement has been
completed. To minimize the chance for any leakage, a small diameter
shaft is used that results in a self-sealing conjunctival wound. To
further reduce the chance for a conjunctival leak, a suture can be
placed in the conjunctiva around the penetration area after the
shunt placement.
[0191] Furthermore the preferred method of penetrating the
conjunctiva is performed by shifting the conjunctival layers from
posterior to the limbus towards the limbus, using e.g. an
applicator such as a Q-tip, before the shaft penetration is
started. This is illustrated in FIGS. 40-41. That figure shows that
an applicator 157 is put onto the conjunctiva 158, about 6 mm away
from the limbus. The loose conjunctiva layer is then pushed towards
the limbus to create folding tissue layers that are about 2 mm away
from the limbus. The device shaft 109 is now inserted through the
conjunctiva and sclera 8 starting about 4 mm away from the limbus.
After the shunt placement has been completed, the Q-tip is released
and the conjunctival perforation relaxes back from about 4 mm to
about 8 mm limb at distance. This can cause the conjunctival
perforation to be 4 mm away from the now slowly starting drainage
exit. This distance will reduce any potential for leakage and
allows for a faster conjunctival healing response. Alternative to
this described upward shift, a sideway shift of the conjunctiva or
anything in between is feasible as well. In another embodiment of
the ab externo method, a conjunctival slit is cut and the
conjunctiva is pulled away from the shaft entry point into the
sclera. After the shunt placement is completed, the conjunctival
slit is closed again through sutures.
[0192] In certain embodiments, since the tissue surrounding the
trabecular meshwork is optically opaque, an imaging technique, such
as ultrasound biomicroscopy (UBM), optical coherence tomography
(OCT) or a laser imaging technique, can be utilized. The imaging
can provide guidance for the insertion of the deployment device and
the deployment of the shunt. This technique can be used with a
large variety of shunt embodiments with slight modifications since
the trabecular meshwork is punctured from the scleral side, rather
than the anterior chamber side, in the ab externo insertion.
[0193] In another ab externo approach, a superficial flap may be
made in the sclera and then a second deep scleral flap may be
created and excised leaving a scleral reservoir under the first
flap. Alternatively, a single scleral flap may be made with or
without excising any portion of the sclera.
[0194] A shaft of a deployment device is inserted under the flap
and advanced through the sclera and into an anterior chamber. The
shaft is advanced into the sclera until a proximal portion of the
shaft resides in the anterior chamber and a distal portion of the
shaft is in proximity to the trabecular outflow. The deployment is
then performed such that an outlet of the shunt is positioned
proximate the second opening in the sclera so that at least some of
the fluid that exits the shunt flows through the first opening in
the sclera, thereby ensuring that the intrascleral space does not
become overwhelmed with fluid output from the shunt. At the
conclusion of the ab externo implantation procedure, the scleral
flap may be sutured closed. The procedure also may be performed
without suturing.
[0195] Regardless of the implantation method employed, some
embodiments of the methods disclosed herein recognize that the
proximity of the distal end of the shunt to the scleral exit slit
affects the flow resistance through the shunt, and therefore
affects the intraocular pressure in the eye. For example, if the
distal end of the shunt 112 is flush with the sclera surface then
there is no scleral channel resistance (FIG. 42). In this
embodiment, total resistance comes from the shunt 112 alone. In
another embodiment, if the distal end of the shunt 112 is about 200
.mu.m to about 500 .mu.m behind the scleral exit, then the scleral
slit closes partially around the exit location, adding some
resistance to the outflow of aqueous humor (FIG. 43). In another
embodiments, if the distal end of the shunt 112 is more than about
500 micron behind the scleral exit, than the scleral slit closes
completely around the exit location with no backpressure and opens
gradually to allow aqueous humor to seep out when the intraocular
pressure raises e.g. above 10 mmHg (FIG. 44). The constant seepage
of aqueous humor keeps the scleral slit from scaring closed over
time.
[0196] Effectively, shunt placement according to some embodiments
of the methods disclosed herein achieve a valve like performance
where the scleral slit in front of the distal shunt end acts like a
valve. The opening (cracking) pressure of this valve can be
adjusted by the outer shunt diameter and its exact distal end
location relative to the scleral exit site. Typical ranges of
adjustment are 1 mmHg to 20 mmHg. This passageway distance can be
controlled and adjusted through the design of the inserting device
as well as the shunt length and the deployment method. Therefore a
specific design can be chosen to reduce or prevent hypotony (<6
mmHg) as a post-operative complication.
[0197] FIGS. 45-51 illustrates placement of a shunt in various
locations of the eye, according to some embodiments. In these
figures, the first end of a shunt is positioned in the region of
lower pressure and a second end of the shunt is positioned in a
region of high pressure. For example, in FIG. 45, an end of a shunt
300 is shown extending into the anterior chamber 1.
[0198] According to some embodiments of the methods disclosed
herein, the shunt can access the region of lower pressure by
extending through the anterior chamber angle tissue. Thus, whether
the shunt is targeting supraciliary space, suprachoroidal space,
the intrascleral space, intra-Tenon's adhesion space, or
subconjunctival space, the shunt can be placed through the anterior
chamber angle tissue.
[0199] FIG. 45 illustrates supraciliary placement of a shunt 300.
As shown, the shunt 300 extends from the anterior chamber 1 to the
supraciliary space 310. FIG. 46 illustrates suprachoroidal
placement of a shunt 320. As shown, the shunt 320 extends from the
anterior chamber 1 to a suprachoroidal space 322. As discussed
above, the supraciliary space 310 can be continuous with the
suprachoroidal space 322.
[0200] FIG. 47 illustrates subconjunctival placement of a shunt
330. As shown, the shunt 330 extends from the anterior chamber 1 to
the subconjunctival space 332. FIG. 48 illustrates intrascleral
placement of a shunt 340. As shown, the shunt 340 extends from the
anterior chamber 1 to the intrascleral space 342.
[0201] FIG. 49 depicts placement of a shunt 350 in the
intra-Tenon's adhesion space 11 of Tenon's capsule 10, according to
some embodiments. As shown, the shunt 350 extends from the anterior
chamber 1 to the intra-Tenon's adhesion space 11. The shunt 350 can
be passed through the sclera 8. In some embodiments, the shunt 350
can extend at least partially through Schlemm's canal 30 and/or the
trabecular meshwork 32. Further, the shunt 350 can extend through
the trabecular meshwork 32 without passing through Schlemm's canal
30. Furthermore, the shunt 350 can extend entirely through the
sclera 8 without passing through Schlemm's canal 30 or the
trabecular meshwork 32. This may be accomplished by passing through
the sclera in a location posterior to Schlemm's canal 34 anterior
to the trabecular meshwork 32, above the scleral spur 36. In
accordance with some embodiments, the shunt 350 can access the
intra-Tenon's adhesion space 11 in a location anterior to the
rectus muscle 20. For example, a distal end of the shunt 350 can be
positioned between the layers of intra-Tenon's adhesion space 11
anterior to the rectus muscle 20.
[0202] FIG. 50 is an enlarged schematic cross-sectional view taken
along section lines 50-50 of FIG. 49. As illustrated in FIG. 50,
the shunt 350 extends through the intra-Tenon's adhesion space 11.
As shown, the intra-Tenon's adhesion space 11 comprises spongy,
porous tissue (adhesions 352) that can facilitate drainage of
aqueous humor from the anterior chamber.
[0203] When placing the shunt 350 into the intra-Tenon's adhesion
space 11, some embodiments of the methods disclosed herein can
comprise accessing the intra-Tenon's adhesion space 11 by inserting
a needle through a deep layer 360 of Tenon's capsule 10 and
positioning a distal end 362 of the shunt 350 into the
intra-Tenon's adhesion space 11.
[0204] For example, the shunt 350 can enter intra-Tenon's adhesion
space 11 and, while maintaining the position of the needle (to
avoid further advancement of the needle into the intra-Tenon's
adhesion space 11), the shunt 350 can then be urged distally into
the intra-Tenon's adhesion space 11 in order to preserve the
adhesions 352 that extend between a superficial layer 370 and the
deep layer 360 of the Tenon's capsule 10.
[0205] In some embodiments, when the deep layer 360 is pierced, the
shunt 350 can be at least partially exposed beyond a distal tip of
a needle and urged distally using a pusher component such that the
shunt moves distally out of the needle while maintaining the needle
in a generally stationary position. For example, FIG. 51
illustrates that the distal end 362 of the shunt 350 can be urged
distally such that the distal end 362 passes between adjacent
adhesions 352, which may cause the shunt 350 to deflect, bend,
and/or curve within the intra-Tenon's adhesion space 11.
Embodiments of such methods can thus be performed to allow
non-destructive access to the intra-Tenon's adhesion space 11.
Deployment Device Motion Sequences
[0206] According to some embodiments, the deployment device can be
operated to release a shunt within the eye using a variety of
motion sequences. The motion sequences can be performed manually or
automatically, with a device. In some embodiments of the sequences
discussed below, the operator or clinician can perform a procedure
using only two discrete motions: advancing the device into the eye
until reaching a final stop position and then, after the shunt has
been implanted into the tissue, retracting the device from the eye.
However, in accordance with some embodiments of the sequences
discussed below, the operator or clinician can also exert a
rotational force on one or more components of the device or on the
device as a whole, to control advancement and release of the shunt.
Further, in some embodiments of the sequences discussed below, the
operator or clinician can perform the procedure using more than two
discrete axial motions, such as: advancing the device into the eye
until reaching a preliminary stop position, and while implanting
the shunt into the tissue, advancing the device toward a final stop
position; thereafter, when the shunt is implanted into the tissue,
the device can be proximally withdrawn from the tissue.
Additionally, in some embodiments of the sequences discussed below,
the operator or clinician can exert axial and rotational forces on
the device to facilitate placement and release of the shunt.
[0207] Various procedures for releasing a shunt into the eye are
discussed below with respect to FIGS. 52A-54E and aspects of this
discussion can be applied to more than one of the embodiments of
the procedures discussed herein. Such procedures allow a clinician
to use a deployment device to place the shunt precisely within the
eye while minimizing any trauma to the surrounding eye tissue.
[0208] As shown, FIGS. 52A-52E illustrate placement of a shunt into
the subconjunctival space. However, as discussed herein, the
desired location can be one of various anatomical locations within
the eye, including, but not limited to the intrascleral space, the
subconjunctival space, and/or the intra-Tenon's adhesion space.
According to some embodiments, the shunt can be positioned such
that one or more drainage outlets of the shunt extends within one
or more anatomical locations within the eye, such as a single
anatomical location, or across multiple anatomical locations,
thereby providing drainage to either a single or multiple
locations.
[0209] Further, according to some embodiments, the deployment
device can comprise a shaft that has a hard tip (e.g., to pierce
the sclera for placing the shunt, e.g., in the intrascleral space,
the subconjunctival space, and/or the intra-Tenon's adhesion space)
or a softer tip (e.g., to advance the shunt, e.g., for placing the
shunt in the supraciliary space and/or suprachoroidal space). Thus,
although the embodiments illustrated in FIGS. 52A-55E illustrate
that placement of a shunt can be through or in sclera, other
embodiments of an implantation procedure can be performed such that
the shunt is placed deep to a deep layer of the sclera.
[0210] According to some embodiments, a shunt can be loaded into
the shaft such that a distal end portion of the shunt is positioned
at the distal end of the shaft 410 (see e.g., FIGS. 23-30 and FIGS.
33-41).
[0211] FIGS. 52A-52E illustrate steps of a method in which a
deployment device 400 can be inserted into the eye 402 and provide
a visual indication or guide for an operator during shunt
placement. The device 400 can be advanced across the anterior
chamber 404 of the eye 402 until a needle or shaft 410 of the
device 400 pierces the tissue at the anterior chamber angle 412,
referred to as anterior chamber angle tissue. The device 400 can
also comprise a sleeve 414 having a lumen in which the shaft 410 is
disposed. The sleeve 414 can comprise a distal end 416 that can be
visible within the anterior chamber 404 of the eye 402. According
to some embodiments, a mark or reference point on the sleeve 414,
for example, the distal end 416 of the sleeve 414, can provide a
visual indication or guide for an operator during placement of the
shunt, so as to locate or assess a final longitudinal position of
the shunt.
[0212] For example, in some embodiments, such as those illustrated
in FIGS. 52A-52E and 54A-54E, the deployment device 400 can be
configured such that when the shunt is being released from the
device 400, a pusher component or plunger of the device 400 can
distally advance the shunt relative to the shaft 410 until the
proximal end of the shunt is approximately longitudinally adjacent
to the distal end 416 of the sleeve 414. Thus, after the pusher
component has been advanced to a desired position (e.g., to a
position in which a distal end of the pusher component is proximal
to, coextensive with, or distal to a distal end of the shaft 410)
within the shaft 410, proximal retraction of the shaft 410 (while
maintaining the sleeve 414 in a desired location) will release the
shunt from the device 400 with the proximal end of the shunt being
finally positioned about where the distal end 416 of the sleeve 414
is positioned. While the relative positions of the distal end 416
of the sleeve 414 and the fully extended pusher component can vary
according to some embodiments (e.g., contrast the embodiment shown
in FIGS. 53A-53E), the visualization of the position of the distal
end 416 (or another marked aspect of the sleeve 414) can facilitate
precise longitudinal placement of the shunt within the eye
tissue.
[0213] According to some embodiments, the mark or reference point
of the sleeve 414 can comprise the distal end 416 or a line
extending crosswise on the sleeve 414 (proximal to the distal end
416). The mark or reference point can comprise a high contrast
element or color to facilitate visualization or discernment of the
location of the marker reference point when the sleeve 414 is
inserted into or toward an aspect of the eye, such as the anterior
chamber 404 or anterior chamber angle 412.
[0214] Further, although a clinician can, in some embodiments,
verify initial placement of the device 400 with reference only to a
mark, reference point, or position of the distal end 416 of the
sleeve 414 relative to an aspect of the eye, such as the anterior
chamber angle tissue or anterior chamber angle 412 itself, the
initial placement or position of the device 400 can also be based
on the position of the shaft 410 within the eye tissue. For
example, for subconjunctival placement of the shunt 420, as the
shaft 410 is advanced through the sclera, a bevel 418 of the shaft
410 will eventually be seen through the conjunctiva (which is
translucent) as the bevel 418 exits the sclera. The clinician,
based on the visual confirmation of the location of the bevel below
418 the conjunctiva, can thereby determine that the shaft 410 has
been advanced sufficiently. To avoid further advancement, which
could result in piercing or damaging the conjunctiva, the clinician
can use the distal end 416 of the sleeve 414 to provide a visual
indication or guide whereby the clinician can maintain the position
of the device 400 steady within the eye. Thus, the bevel 418 can be
maintained in a position adjacent to or opening to the
subconjunctival space.
[0215] In some embodiments, such as that illustrated in FIGS.
52A-52E, as the device 400 is moved through the anterior chamber
404 and into initial position within the eye tissue, the shaft 410
can be positioned relative to the sleeve 414 such that the bevel
418 is spaced about 3 mm to about 7 mm, about 4 mm to about 6 mm,
or about 5 mm from the distal end 416 of the sleeve 414. Such
spacing can allow the distal end 416 of the sleeve 414 to be spaced
apart from the anterior chamber angle tissue when the bevel 418
emerges from the sclera to become visible under the conjunctiva.
Thus, the clinician can advantageously confirm proper initial
placement of the device 400 by verifying bevel emergence from the
sclera if it would otherwise be difficult to visually verify a
relative positioning of the distal end 416 of the sleeve 414 and
the anterior chamber angle tissue or anterior chamber angle 412.
This provides freedom to allow for variability in the anatomy
and/or trajectory of the advancing shaft 410 (e.g., for differences
in the thickness of sclera from patient to patient).
[0216] After the device 400 has been advanced through the anterior
chamber 404 and the needle or shaft 410 has pierced the anterior
chamber angle tissue at the anterior chamber angle 412, the shunt
420 can be advanced such that a distal end portion 422 of the shunt
420 is moved into or positioned at a desired location within the
eye 402 (here shown as the subconjunctival space 430).
[0217] The advancement of the distal end portion 422 of the shunt
420 into the desired location of the eye 402 can be performed by
advancing the pusher component (not shown) relative to the shaft
410 while maintaining the shaft 410 and the sleeve 414 steady, at a
generally constant position or location, until the distal end
portion 422 has been fully advanced into the desired location, as
illustrated in FIGS. 52B-52C. Thereafter, as shown in FIG. 52D, the
shaft 410 can be proximally withdrawn relative to the shunt 420. In
some embodiments, the shaft 410 can also be proximally withdrawn
relative to the sleeve 414 and the pusher component while
maintaining the sleeve 414 steady, at a generally constant position
or location relative to the tissue. As the shaft 410 is proximally
withdrawn from the tissue of the eye 402, the pusher component
maintains the longitudinal position of the shunt 420 in order to
ensure that the distal end portion 422 remains embedded at the
desired location. Accordingly, proximal withdrawal of the shaft
410, while maintaining the position of the shunt 420 in the eye
402, allows further exposure of the shunt 422 surrounding
tissue.
[0218] Eventually, after the shunt 420 is released or embedded
within the eye tissue, the shaft 410 can be fully withdrawn from
covering or enclosing the shunt 420, as shown in FIG. 52E. Further,
in some embodiments, the shaft 410 can be completely retracted into
the lumen of the sleeve 414, as also illustrated in FIG. 52E. The
shaft 410 and the pusher component can be further withdrawn or
retracted together into the lumen of the sleeve 414, as necessary.
Thereafter, the device 400 can be proximally withdrawn from the eye
402 and the procedure can be completed.
[0219] In accordance with some embodiments, the device 400 can also
deliver the shunt 420 by allowing the distal end 416 of the sleeve
414 to contact or abut tissue within the eye. For example, the
distal end 416 of the sleeve 414 can comprise one or more blunt
structures, such as an edge, protrusion, and/or an annular,
enlarged portion, that can be abutted with tissue of the eye 402,
such as the anterior chamber angle tissue.
[0220] For example, referring to FIGS. 53A-53E, after the device
400 is advanced into the anterior chamber 404, as discussed above
with respect to FIG. 52A, the needle or shaft 410 can pierce the
anterior chamber angle tissue. According to some embodiments, the
device 400 can be advanced until the distal end 416 of the shaft
414 abuts the anterior chamber angle tissue of the anterior chamber
angle 412. This abutment can provide resistance feedback to an
operator, indicating that no further advancement of the device 400
is necessary. As discussed herein, the device 400 can comprise a
blunt structure to prevent the shaft 410 from accidentally being
pushed too far through the eye tissue.
[0221] In some embodiments, such as that illustrated in FIGS.
53A-53E, as the device 400 is moved through the anterior chamber
404 and into initial position within the eye tissue, the shaft 410
can be positioned relative to the sleeve 414 such that the bevel
418 is spaced about 2 mm to about 6 mm, about 3 mm to about 5 mm,
or about 4 mm from the distal end 416 of the sleeve 414. Such
spacing can tend to ensure that the distal end 416 of the sleeve
414 is able to contact the anterior chamber angle tissue as the
bevel 418 emerges from the sclera, but avoid piercing of the
sclera.
[0222] Once the distal end 416 of the sleeve 414 is positioned
abutting the tissue of the eye 402, the shunt 420 can be advanced
distally, e.g., by using a pusher component (not shown), until a
distal end portion 430 of the shunt 420 is positioned at the
desired location, as shown in FIG. 53C. In some embodiments, such
as that shown in FIGS. 53A-53E, the position of the distal end 416
of the sleeve 414 relative to the fully extended pusher component
can be configured such that a maximum distal displacement or
maximum distal position of the pusher component is longitudinally
proximal to the sleeve distal end 416 when the pusher component is
advanced within the shaft (see also FIGS. 23-30). For example, the
pusher component can have a distalmost position of between about 0
mm and about 8 mm, about 0 mm and about 4 mm, about 0 mm and about
2 mm, or about 0 mm and about 1 mm proximal to the sleeve distal
end.
[0223] Thereafter, once the shunt 420 is advanced to its final
position, as shown in FIG. 53D, the shaft 410 can be proximally
withdrawn relative to the sleeve 414 to further expose the shunt
420 to surrounding tissue. Additionally, as shown in FIG. 53E, and
as discussed above, the shaft 410 can be fully withdrawn into the
sleeve 414. Finally, the device 400 can be removed from the eye and
the procedure can be completed.
[0224] Further, in the embodiment illustrated in FIGS. 54A-54E, the
device 400 can be advanced through the anterior chamber 404 and the
shaft 410 can pierce and enter eye tissue. The device 400 can be
advanced until a distal end 416 of the sleeve 414 is positioned
adjacent to or spaced apart from, but not abutting, the anterior
chamber angle tissue or is positioned within the anterior chamber
angle 412 (a similar initial position to that of FIG. 52B). Such a
position can be a preliminary stop position, as mentioned above, at
which the clinician can cease advancement of the device 400.
[0225] In such embodiments, after the device 400 has been initially
placed in the anterior chamber angle tissue or anterior chamber
angle 412, the shunt 420 can be released by a motion sequence in
which the shaft 410 is maintained steady within the tissue while
the distal end 416 of the sleeve 414 is advanced to abut the
anterior chamber angle tissue, as discussed below. Such a motion
can, in some embodiments, require that the operator or clinician
further advance the device 400 axially until reaching a final stop
position, achieved when the distal end 416 of the sleeve 414 abuts
the anterior chamber angle tissue. However, the device 400 can also
be configured to allow the sleeve 414 to move relative to a housing
of the device, thereby allowing the operator or clinician to
maintain the device 400 stationary relative to the face of the
patient as the sleeve 414 is advanced further toward the anterior
chamber angle tissue.
[0226] As illustrated in FIGS. 54A-54B, the device 400 initially
enters the anterior chamber 404 and is advanced until the shaft 410
pierces the anterior chamber angle tissue. The distal end 416 of
the sleeve 414 can be maintained or held spaced apart from the eye
tissue or anterior chamber angle 412, at an initial placement or
position such as that discussed above with respect to FIG. 52B.
Although a clinician can, in some embodiments, verify initial
placement of the device 400 with reference only to the position of
the distal end 416 of the sleeve 414 relative to the anterior
chamber angle tissue or anterior chamber angle 412, the initial
placement or position of the device 400 can also be based on the
position of the shaft 410 within the eye tissue.
[0227] For example, as similarly discussed above, for
subconjunctival placement of the shunt 420, the shaft 410 (and
hence, the sleeve 414) will be at its proper location when a bevel
418 of the shaft 410 has exited or emerged from the sclera, but has
not penetrated the conjunctiva. This emergence can be visually
verified because the bevel 418 can be seen through or below the
conjunctiva (which is translucent). Thereafter, the position of the
device 400 within the eye 402 can be maintained steady such that
the bevel 418 remains positioned adjacent to or opening to the
subconjunctival space.
[0228] In such embodiments, such as that illustrated in FIGS.
54A-54E, as the device 400 is moved through the anterior chamber
404 and into initial position within the eye tissue, the shaft 410
can be positioned relative to the sleeve 414 such that the bevel
418 is spaced about 1 mm to about 5 mm, about 2 mm to about 4 mm,
or about 3 mm from the distal end 416 of the sleeve 414. Such
spacing can allow the distal end 416 of the sleeve 414 to be spaced
apart from the eye tissue or anterior chamber angle 412 when the
bevel 418 emerges from the sclera. Thus, the clinician can
advantageously confirm proper initial placement of the device 400
by verifying bevel emergence from the sclera if it would otherwise
be difficult to visually verify a relative positioning of the
distal end 416 of the sleeve 414 and the tissue or anterior chamber
angle 412. This provides freedom to allow for variability in the
anatomy and/or trajectory of the advancing shaft 410.
[0229] Once initial placement of the device 400 is proper, the
motion sequence can continue by initiating relative movement
between the shaft 410, the sleeve 414, and pusher component (not
shown) to begin releasing the shunt 420.
[0230] As illustrated in FIGS. 54C-54D, after the device 400
reaches the initial position, the shunt 420 can be distally
advanced into the tissue until a distal end portion 430 reaches the
desired location. The advancement of the distal end portion 422 of
the shunt 420 into the desired location of the eye 402 can be
performed by advancing the pusher component (not shown) relative to
the shaft 410 while maintaining the shaft 410 and the sleeve 414
steady, at a generally constant position or location.
[0231] Further, as illustrated in FIG. 54D, the shaft 410 can be
proximally withdrawn into the sleeve 414. However, instead of
maintaining the sleeve 414 at a generally constant position or
location relative to the eye while the shaft 410 is withdrawn into
the sleeve 414 (and in contrast to the embodiments discussed in
FIGS. 52A-53E), the shaft 410 can be obtained at a generally
constant position relative to the eye tissue while the sleeve 414
moves relative to the eye tissue.
[0232] For example, the relative movement between the sleeve 414
and the shaft 410 while the shaft 410 remains at a constant
position relative to the eye tissue causes the sleeve 414 to be
longitudinally advanced along the shaft 410, distally toward the
eye tissue or anterior chamber angle 412. Thus, the sleeve 414 can
move while the shaft 410 is held steady in the eye, at a generally
constant position or location within the tissue. Accordingly, the
sleeve 414 will be distally advanced toward the anterior chamber
angle 412 until the distal end 416 of the sleeve 414 contacts or
abuts the eye tissue, such as the anterior chamber angle
tissue.
[0233] In some embodiments, the sleeve 414 can be advanced distally
along the shaft 410 by about 1 mm, about 2 mm, about 3 mm, about 4
mm, about 5 mm, about 6 mm, or more, as necessary, until contacting
eye tissue.
[0234] For example, the sleeve distal end 416 can be distally
advanced between about 1 mm to about 4 mm or between about 2 mm to
about 3 mm. The sleeve can be advanced at a rate of between about
0.15 mm/sec to about 0.85 mm/sec, and in some embodiments, between
about 0.25 mm/sec to about 0.65 mm/sec.
[0235] When the distal end 416 abuts the eye tissue, further
relative retraction of the shaft 410 into the sleeve 414 will cause
the shaft 410 to be proximally withdrawn from the tissue because
the distal end 416 of the sleeve 414 has now abutted the anterior
chamber angle tissue, as illustrated in FIGS. 54D-54E. Continued
retraction or withdrawal of the shaft 410 can cause the shaft 410
to be fully withdrawn into the lumen of the sleeve 414.
[0236] Aspects of the procedures discussed herein, including those
discussed with respect to FIGS. 52A-54E, can be implemented in
various embodiments of a procedure for implanting an intraocular
shunt. The deployment device can operate according to the features
of any of the embodiments disclosed herein.
[0237] In any of the procedures discussed above with respect FIGS.
52A-54E, when the bevel 418 has been advanced through the sclera
toward the subconjunctival space, it may be necessary to further
actuate the bevel 418 in order to ensure that the subconjunctival
space has been reached and can be easily accessed by the shunt.
[0238] First, some clinicians may tend to conservatively advance
the bevel 418 within the sclera and fail to reach the
subconjunctival space such that the bevel 418 is placed between the
sclera and the conjunctiva. In such situations, when the bevel 418
has been advanced to a position shy of the subconjunctival space
within the sclera, the bevel 418 can be rotated within the sclera
to permit the bevel 418 to "crack" the sclera and ensure that the
subconjunctival space has been accessed. The rotation of the bevel
418 can cause the oblong or oval shape of the bevel 418 to rotate
from a flat position to an upright position, thereby pushing,
breaking, or otherwise breaching the top surface of the sclera so
that the lumen of the shaft 410 opens to the subconjunctival space
to allow the shunt 420 to be advanced therefrom.
[0239] Second, in order to ensure that the subconjunctival space
can be easily accessed by the shunt, even when the sclera has been
breached in the subconjunctival space has been accessed, rotating
the bevel 418 can cause the conjunctiva to become "tented" or
spaced apart from the top surface of the sclera. This "tenting" of
the conjunctiva can create a pocket within the subconjunctival
space. When advancing the shunt 420, the pocket will provide little
frictional resistance or threat of impeding travel of the shunt 420
within the subconjunctival space. Accordingly, the shunt 420 can
more readily begin its entry into the subconjunctival space, thus
avoiding kinking or bending of the shunt 420 due to high frictional
resistance that would otherwise be present absent the creation of
the pocket within the subconjunctival space.
[0240] Further teachings regarding the rotation or actuation of the
bevel 418 within the sclera are disclosed in Applicant's copending
U.S. patent application Ser. No. 12/946,556, filed Nov. 15, 2010,
the entirety of which is incorporated herein by reference.
[0241] Further, the relative positioning of a shunt within the
shaft and the range of movement of the pusher component within the
shaft can be selectively modified to optimize the position of the
shunt end portions when performing the motion sequences of the
deployment device. In particular, to ensure proper placement of the
distal end portion of the shunt, the maximum distal or fully
advanced position of the pusher component relative to the sleeve
distal end can be optimized.
[0242] For example, as noted above, the pusher component can have a
maximum distal displacement or maximum distal position that results
in the pusher component being positioned at least longitudinally
adjacent to (longitudinally coextensive with) the sleeve distal end
or distally beyond the sleeve distal end when the distal end of the
sleeve distal end is maintained spaced apart from the eye tissue
(e.g., spaced apart from the anterior chamber angle tissue), when
the pusher component is advanced within the shaft (see FIGS. 33-41,
FIGS. 52B-52C, and FIGS. 54B-54C). For example, the pusher
component can have a distalmost position of between 0 mm and about
8 mm, about 0 mm and about 4 mm, about 0 mm and about 2 mm, or
about 0 mm and about 1 mm beyond or distal to the sleeve distal
end.
[0243] Further, as noted above, the pusher component can have a
maximum distal displacement or maximum distal position that results
in the pusher component being positioned longitudinally proximal to
the sleeve distal end when the pusher component is advanced within
the shaft (see FIGS. 23-30 and FIGS. 53B-53C). For example, the
pusher component can have a distalmost position of between about 0
mm and about 8 mm, about 0 mm and about 4 mm, about 0 mm and about
2 mm, or about 0 mm and about 1 mm proximal to the sleeve distal
end.
[0244] The foregoing description is provided to enable a person
skilled in the art to practice the various configurations described
herein. While the subject technology has been particularly
described with reference to the various figures and configurations,
it should be understood that these are for illustration purposes
only and should not be taken as limiting the scope of the subject
technology.
[0245] There may be many other ways to implement the subject
technology. Various functions and elements described herein may be
partitioned differently from those shown without departing from the
scope of the subject technology. Various modifications to these
configurations will be readily apparent to those skilled in the
art, and generic principles defined herein may be applied to other
configurations. Thus, many changes and modifications may be made to
the subject technology, by one having ordinary skill in the art,
without departing from the scope of the subject technology.
[0246] It is understood that the specific order or hierarchy of
steps in the processes disclosed is an illustration of exemplary
approaches. Based upon design preferences, it is understood that
the specific order or hierarchy of steps in the processes may be
rearranged. Some of the steps may be performed simultaneously. The
accompanying method claims present elements of the various steps in
a sample order, and are not meant to be limited to the specific
order or hierarchy presented.
[0247] Terms such as "top," "bottom," "front," "rear" and the like
as used in this disclosure should be understood as referring to an
arbitrary frame of reference, rather than to the ordinary
gravitational frame of reference. Thus, a top surface, a bottom
surface, a front surface, and a rear surface may extend upwardly,
downwardly, diagonally, or horizontally in a gravitational frame of
reference.
[0248] Furthermore, to the extent that the term "include," "have,"
or the like is used in the description or the claims, such term is
intended to be inclusive in a manner similar to the term "comprise"
as "comprise" is interpreted when employed as a transitional word
in a claim.
[0249] The word "exemplary" is used herein to mean "serving as an
example, instance, or illustration." Any embodiment described
herein as "exemplary" is not necessarily to be construed as
preferred or advantageous over other embodiments.
[0250] A reference to an element in the singular is not intended to
mean "one and only one" unless specifically stated, but rather "one
or more." Pronouns in the masculine (e.g., his) include the
feminine and neuter gender (e.g., her and its) and vice versa. The
term "some" refers to one or more. Underlined and/or italicized
headings and subheadings are used for convenience only, do not
limit the subject technology, and are not referred to in connection
with the interpretation of the description of the subject
technology. All structural and functional equivalents to the
elements of the various configurations described throughout this
disclosure that are known or later come to be known to those of
ordinary skill in the art are expressly incorporated herein by
reference and intended to be encompassed by the subject technology.
Moreover, nothing disclosed herein is intended to be dedicated to
the public regardless of whether such disclosure is explicitly
recited in the above description.
[0251] While certain aspects and embodiments of the inventions have
been described, these have been presented by way of example only,
and are not intended to limit the scope of the inventions. Indeed,
the novel methods and systems described herein may be embodied in a
variety of other forms without departing from the spirit thereof.
The accompanying claims and their equivalents are intended to cover
such forms or modifications as would fall within the scope and
spirit of the inventions.
* * * * *