U.S. patent application number 11/585043 was filed with the patent office on 2007-04-19 for indwelling shunt device and methods for treating glaucoma.
Invention is credited to Reay H. Brown, Stephane Gobron, Mary G. Lynch, Kenneth Solovay.
Application Number | 20070088432 11/585043 |
Document ID | / |
Family ID | 34657842 |
Filed Date | 2007-04-19 |
United States Patent
Application |
20070088432 |
Kind Code |
A1 |
Solovay; Kenneth ; et
al. |
April 19, 2007 |
Indwelling shunt device and methods for treating glaucoma
Abstract
The present invention is directed to a novel indwelling shunt
implant and an associated surgical method for the treatment of
glaucoma in which the implant device comprises at least one spiral
body and/or grooved or corrugated body and is placed to divert
aqueous humor from the anterior chamber of the eye into Schlemm's
canal, the collector channels, or the aqueous venous system or to
distribute aqueous fluid within Schlemm's canal. The present
invention is further directed to providing a permanent, indwelling
shunt to provide increased egress of aqueous humor from the
anterior chamber to Schlemm's canal, collector channels, or aqueous
venous system for glaucoma management.
Inventors: |
Solovay; Kenneth; (Weston,
FL) ; Gobron; Stephane; (Carlsbad, CA) ;
Lynch; Mary G.; (Atlanta, GA) ; Brown; Reay H.;
(Atlanta, GA) |
Correspondence
Address: |
LOTT & FRIEDLAND, P.A.
ONE EAST BROWARD BLVD.
SUITE 1609
FORT LAUDERDALE
FL
33301
US
|
Family ID: |
34657842 |
Appl. No.: |
11/585043 |
Filed: |
October 23, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10222209 |
Aug 16, 2002 |
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11585043 |
Oct 23, 2006 |
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09558505 |
Apr 26, 2000 |
6450984 |
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11585043 |
Oct 23, 2006 |
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60312799 |
Aug 16, 2001 |
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60131030 |
Apr 26, 1999 |
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Current U.S.
Class: |
623/4.1 |
Current CPC
Class: |
A61F 2250/0067 20130101;
A61M 25/0068 20130101; A61F 9/00781 20130101; A61M 25/007 20130101;
A61F 9/0017 20130101; A61M 2210/0612 20130101 |
Class at
Publication: |
623/004.1 |
International
Class: |
A61F 2/14 20060101
A61F002/14 |
Claims
1. An aqueous humor shunt device to divert aqueous humor in an eye
from the anterior chamber into Schlemm's canal, the shunt device
comprising a distal portion having at least one terminal aspect
sized and shaped to be received circumferentially within a portion
of Schlemm's canal wherein the terminal aspect is an open coil and
a proximal portion having at least one terminal aspect sized and
shaped to be received within the anterior chamber of the eye,
wherein device permits fluid communication from the proximal
portion in the anterior chamber to the distal portion in Schlemm's
canal.
2. The shunt device of claim 1 where in the distal end terminates
in a ball shape.
3. The shunt device of claim 2 wherein the ball shape is an insert
in the distal end.
4. The shunt device of claim 2 wherein the ball shape is formed
from the coil of the distal end.
5. The shunt device of claim 1 wherein the proximal end of the
shunt is a dual lumen spring
6. The shunt device of claim 1 wherein the shunt is made from shape
memory materials.
7. The shunt device of claim 1 wherein the shunt is from 1.0 mm to
40.0 mm in length and an outer diameter of between about 0.1 to
about 0.5 mm
8. An aqueous humor shunt device to divert aqueous humor in an eye
from the anterior chamber into Schlemm's canal, the shunt device
comprising a distal portion having at least one terminal aspect
sized and shaped to be received circumferentially within a portion
of Schlemm's canal wherein the terminal aspect comprises a flexible
member having at least on conduit for fluid flow on the exterior of
the flexible member and a proximal portion having at least one
terminal aspect sized and shaped to be received within the anterior
chamber of the eye, wherein device permits fluid communication from
the proximal portion in the anterior chamber to the distal portion
in Schlemm's canal.
9. The shunt of claim 8 wherein the flexible member has spiral or
helical ridges running from the proximal to the distal end which
define the conduit for fluid flow.
10. The shunt of claim 7 wherein the flexible member has straight
or undulating ridges running from the proximal to the distal end
which define the conduit for fluid flow.
11. The shunt device of claim 8 wherein the shunt is from 1.0 mm to
40.0 mm in length and an outer diameter of between about 0.1 to
about 0.5 mm
12. An aqueous humor shunt device to divert aqueous humor within
Schlemm's canal, the shunt device comprising a distal portion
having at least one terminal aspect sized and shaped to be received
wholly within a portion of Schlemm's canal wherein the terminal
aspect comprises a flexible member having ridges that define at
least one conduit for fluid flow on the exterior of the flexible
member, wherein the device permits fluid communication along the
shunt within Schlemm's canal.
13. The shunt of claim 12 wherein the flexible member has spiral or
helical ridges running from the proximal to the distal end which
define the conduit for fluid flow.
14. The shunt of claim 12 wherein the flexible member has straight
or undulating ridges running from the proximal to the distal end
which define the conduit for fluid flow.
15. The shunt device of claim 12 wherein the shunt is from 1.0 mm
to 40.0 mm in length and an outer diameter of between about 0.1 to
about 0.5 mm
16. An aqueous humor shunt device to divert aqueous humor within
Schlemm's canal, the shunt device comprising a distal portion
having at least one terminal aspect sized and shaped to be received
wholly within a portion of Schlemm's canal wherein the terminal
aspect comprises an open coil having a lumen there through wherein
the device permits fluid communication along the shunt within
Schlemm's canal.
17. The shunt device of claim 16 where in the distal end terminates
in a ball shape.
18. The shunt device of claim 17 wherein the ball shape is an
insert in the distal end.
19. The shunt device of claim 17 wherein the ball shape is formed
from the coil of the distal end.
20. The shunt device of claim 16 wherein the shunt is made from
shape memory materials.
21. The shunt device of claim 16 wherein the shunt is from 1.0 mm
to 40.0 mm in length and an outer diameter of between about 0.1 to
about 0.5 mm
22. An aqueous humor shunt device to divert aqueous humor within
Schlemm's canal, the shunt device comprising a distal portion
having at least one terminal aspect sized and shaped to be received
wholly within a portion of Schlemm's canal wherein the terminal
aspect comprises a corrugated member having at least one aperture
in the corrugation that defines at least one conduit for fluid flow
on the interior of the flexible member, wherein device permits
fluid communication inside the shunt within Schlemm's canal.
23. The device according to claim 23 wherein the corrugations are
formed by transverse members alternating above and below a pair of
longitudinal rails.
24. The device according to claim 23 wherein the corrugations are
sinusoidal.
25. The device according to claim 25 wherein the corrugations are
squared off.
26. The device according to claim 23 wherein the hunt is from 1.0
mm to 40.0 mm in length and an outer diameter of between about 0.1
to about 0.5 mm.
27. A method of treating glaucoma in a patient in need thereof
comprising: First introducing a second end into Schlemm's canal
wherein the second end comprises an open coil or stent; Second
introducing a first end of a shunt device into the anterior chamber
of the eye, wherein the first end comprises a silicone tube,
thereby allowing aqueous fluid to flow from the anterior chamber
into Schlemm's canal.
Description
TECHNICAL FIELD
[0001] The present invention is generally directed to a surgical
treatment for glaucoma, and relates more particularly to a device
and method for continuously decreasing elevated intraocular
pressure in eyes affected by glaucoma by diverting aqueous humor
from the anterior chamber of the eye into Schlemm's canal,
collector channel, or aqueous venous system where post-operative
patency of Schlemm's canal can be maintained with an indwelling
implant which can be surgically placed to connect the canal with
the anterior chamber.
BACKGROUND OF THE INVENTION
[0002] Glaucoma is a significant public health problem, because
glaucoma is a major cause of blindness. The blindness that results
from glaucoma involves both central and peripheral vision and has a
major impact on an individual's ability to lead an independent
life.
[0003] Glaucoma is an optic neuropathy (a disorder of the optic
nerve) that usually occurs in the setting of an elevated
intraocular pressure. The pressure within the eye increases and
this is associated with changes in the appearance ("cupping") and
function ("blind spots" in the visual field) of the optic nerve. If
the pressure remains high enough for a long enough period of time,
total vision loss occurs. High pressure develops in an eye because
of an internal fluid imbalance.
[0004] The eye is a hollow structure that contains a clear fluid
called "aqueous humor." Aqueous humor is formed in the posterior
chamber of the eye by the ciliary body at a rate of about 2.5
microliters per minute. The fluid, which is made at a fairly
constant rate, then passes around the lens, through the pupillary
opening in the iris and into the anterior chamber of the eye. Once
in the anterior chamber, the fluid drains out of the eye through
two different routes. In the "uveoscleral" route, the fluid
percolates between muscle fibers of the ciliary body. This route
accounts for approximately 5-25 percent of the aqueous outflow in
humans. The primary pathway for aqueous outflow in humans is
through the "canalicular" route that involves the trabecular
meshwork and Schlemm's canal.
[0005] The trabecular meshwork and Schlemm's canal are located at
the junction between the iris and the sclera. This junction or
corner is called "the angle." The trabecular meshwork is a
wedge-shaped structure that runs around the circumference of the
eye. It is composed of collagen beams arranged in a
three-dimensional sieve-like structure. The beams are lined with a
monolayer of cells called trabecular cells. The spaces between the
collagen beams are filled with an extracellular substance that is
produced by the trabecular cells. These cells also produce enzymes
that degrade the extracellular material. Schlemm's canal is
adjacent to the trabecular meshwork. The outer wall of the
trabecular meshwork coincides with the inner wall of Schlemm's
canal. Schlemm's canal is a tube-like structure that runs around
the circumference of the cornea. In human adults, Schlemm's Canal
is believed to be divided by septa into a series of autonomous,
dead-end canals.
[0006] The aqueous fluid travels through the spaces between the
trabecular beams, across the inner wall of Schlemm's canal into the
canal, through a series of about 20-35 collecting channels that
drain from Schlemm's canal and into the episcleral venous system.
In a normal situation, aqueous production is equal to aqueous
outflow and intraocular pressure remains fairly constant in the 15
to 21 mmHg range. In glaucoma, the resistance through the
canalicular outflow system is abnormally high.
[0007] In primary open angle glaucoma, which is the most common
form of glaucoma, the abnormal resistance is believed to be along
the outer aspect of trabecular meshwork and the inner wall of
Schlemm's canal. It is believed that an abnormal metabolism of the
trabecular cells leads to an excessive build up of extracellular
materials or a build up of abnormally "stiff" materials in this
area. Primary open angle glaucoma accounts for approximately
eighty-five percent of all glaucoma. Other forms of glaucoma (such
as angle closure glaucoma and secondary glaucomas) also involve
decreased outflow through the canalicular pathway but the increased
resistance is from other causes such as mechanical blockage,
inflammatory debris, cellular blockage, etc.
[0008] With the increased resistance, the aqueous fluid builds up
because it cannot exit fast enough. As the fluid builds up, the
intraocular pressure (IOP) within the eye increases. The increased
IOP compresses the axons in the optic nerve and also may compromise
the vascular supply to the optic nerve. The optic nerve carries
visual signals from the eye to the brain. Some optic nerves seem
more susceptible to elevated IOP than other eyes. While research is
investigating ways to protect the nerve from an elevated pressure,
the only therapeutic approach currently available in glaucoma is to
reduce the intraocular pressure.
[0009] The clinical treatment of glaucoma is currently approached
in a step-wise fashion. Medication often is the first treatment
option. Administered either topically or orally, these medications
work to either reduce aqueous production or they act to increase
outflow. Currently available medications may have a number of
serious side effects including: congestive heart failure,
respiratory distress, hypertension, depression, renal stones,
aplastic anemia, sexual dysfunction and death. Compliance with
medication is a major problem, with estimates that over half of
glaucoma patients do not follow their correct dosing schedules.
[0010] When medication fails to adequately reduce the pressure,
laser trabeculoplasty often is performed. In laser trabeculoplasty,
thermal energy from a laser is applied to a number of noncontiguous
spots in the trabecular meshwork. It is believed that the laser
energy stimulates the metabolism of the trabecular cells in some
way, and changes the extracellular material in the trabecular
meshwork. In approximately eighty percent of patients, aqueous
outflow is enhanced and IOP decreases. However, the effect often is
not long lasting and fifty percent of patients develop an elevated
pressure within five years. The laser surgery is not usually
repeatable. In addition, laser trabeculoplasty is not an effective
treatment for primary open angle glaucoma in patients less than
fifty years of age, nor is it effective for angle closure glaucoma
and many secondary glaucomas.
[0011] If laser trabeculoplasty does not reduce the pressure
enough, then filtering surgery is performed. With filtering
surgery, a hole is made in the sclera and angle region. This hole
allows the aqueous fluid to leave the eye externally through an
alternate route.
[0012] The most commonly performed filtering procedure is a
trabeculectomy. In a trabeculectomy, a posterior incision is made
in the conjunctiva, the transparent tissue that covers the sclera.
The conjunctiva is rolled forward, exposing the sclera at the
limbus. A partial thickness scleral flap is made and dissected
half-thickness into the cornea. The anterior chamber is entered
beneath the scleral flap and a section of deep sclera and
trabecular meshwork is excised. The scleral flap is loosely sewn
back into place. The conjunctival incision is tightly closed.
Post-operatively, the aqueous fluid passes through the hole,
beneath the scleral flap and collects in an elevated space beneath
the conjunctiva. The fluid then is either absorbed through blood
vessels in the conjunctiva or traverses across the conjunctiva into
the tear film.
[0013] Trabeculectomy is associated with many problems. Fibroblasts
that are present in the episclera proliferate and migrate and can
scar down the scleral flap. Failure from scarring may occur,
particularly in children and young adults. Of eyes that have an
initially successful trabeculectomy, eighty percent will fail from
scarring within three to five years after surgery. To minimize
fibrosis, surgeons now are applying antifibrotic agents such as
mitomycin C (MMC) and 5-fluorouracil (5-FU) to the scleral flap at
the time of surgery. The use of these agents has increased the
success rate of trabeculectomy but also has increased the
prevalence of hypotony. Hypotony is a problem that develops when
aqueous flows out of the eye too fast. The eye pressure drops too
low (usually less than 6.0 mmHg); the structure of the eye
collapses and vision decreases.
[0014] Trabeculectomy creates a pathway for aqueous fluid to escape
to the surface of the eye. At the same time, it creates a pathway
for bacteria that normally live on the surface of the eye and
eyelids to get into the eye. If this happens, an internal eye
infection can occur called endophthalmitis. Endophthalmitis often
leads to permanent and profound visual loss. Endophthalmitis can
occur anytime after trabeculectomy. The risk increases with the
thin blebs that develop after MMC and 5-FU. Another factor that
contributes to infection is the placement of a bleb. Eyes that have
trabeculectomy performed inferiorly have about five times the risk
of eye infection than eyes that have a superior bleb. Therefore,
initial trabeculectomy is performed superiorly under the eyelid, in
either the nasal or temporal quadrant.
[0015] In addition to scarring, hypotony and infection, there are
other complications of trabeculectomy. The bleb can tear and lead
to profound hypotony. The bleb can be irritating and can disrupt
the normal tear film, leading to blurred vision. Patients with
blebs generally cannot wear contact lenses. All of the
complications from trabeculectomy stem from the fact that fluid is
being diverted from inside the eye to the external surface of the
eye.
[0016] When trabeculectomy doesn't successfully lower the eye
pressure, the next surgical step often is an aqueous shunt device.
An aqueous diversion device of the prior art is a silicone tube
that is attached at one end to a plastic (polypropylene or other
synthetic) plate. With an aqueous shunt device, an incision is made
in the conjunctiva, exposing the sclera. The plastic plate is sewn
to the surface of the eye posteriorly, usually over the equator. A
full thickness hole is made into the eye at the limbus, usually
with a needle. The tube is inserted into the eye through this hole.
The external portion of the tube is covered with either donor
sclera or pericardium. The conjunctiva is replaced and the incision
is closed tightly.
[0017] With prior art aqueous diversion devices, aqueous drains out
of the eye through the silicone tube to the surface of the eye.
Deeper orbital tissues then absorb the fluid. The outside end of
the tube is protected from fibroblasts and scarring by the plastic
plate. Many complications are associated with aqueous shunt
devices. A thickened wall of scar tissue that develops around the
plastic plate offers some resistance to outflow and in many eyes
limits the reduction in eye pressure. In some eyes, hypotony
develops because the flow through the tube is not restricted. Many
physicians tie an absorbable suture around the tube and wait for
the suture to dissolve post-operatively at which time enough scar
tissue has hopefully formed around the plate. Some devices contain
a pressure-sensitive valve within the tube, although these valves
may not function properly. The surgery involves operating in the
posterior orbit and many patients develop an eye muscle imbalance
and double vision post-operatively. With prior art aqueous shunt
devices, a pathway is created for bacteria to get into the eye and
endophthalmitis can potentially occur.
[0018] The prior art includes a number of such aqueous shunt
devices, such as U.S. Pat. No. 4,936,825 (providing a tubular shunt
from the anterior chamber to the corneal surface for the treatment
of glaucoma), U.S. Pat. No. 5,127,901 (directed to a transscleral
shunt from the anterior chamber to the subconjunctival space), U.S.
Pat. No. 5,180,362 (teaching a helical steel implant that is placed
to provide drainage from the anterior chamber to the
subconjunctival space), and U.S. Pat. No. 5,433,701 (generally
teaching shunting from the anterior chamber to the scleral or
conjunctival spaces).
[0019] In addition to the prior art aqueous shunt devices described
above, other prior art devices for glaucoma surgery have used
setons, or other porous, wick-like components to divert and convey
excess aqueous from the anterior chamber to the exterior ocular
surface. Examples include U.S. Pat. Nos. 4,634,418 and 4,787,885
(teaching the surgical treatment of glaucoma using an implant that
consists of a triangular seton (wick)), and U.S. Pat. No.
4,946,436, (teaching the use of a porous device to shunt anterior
chamber to subscleral space). These patents do not teach placement
in Schlemm's canal.
[0020] Some prior art references for glaucoma management have been
directed at Schlemm's canal, but these have not involved the
placement of long-term, indwelling shunts. U.S. Pat. No. 5,360,399
teaches the temporary placement of a plastic or steel tube with
preformed curvature in Schlemm's canal with injection of a viscous
material through the tube to hydraulically expand and hydrodissect
the trabecular meshwork. The tube is removed from the canal
following injection. Because the tube is directed outwardly from
the eye for injection access, the intersection of the outflow
element with the preformed curved element within Schlemm's canal is
at about a 90 degree angle relative to the plane of the curvature,
and 180 degrees away from the anterior chamber. Therefore, at no
time does any portion of the '399 device communicate with the
anterior chamber. Furthermore, relative to that portion within
Schlemm's canal, this tube has a larger diameter injection cuff
element, which serves as an adapter for irrigation. Therefore, this
device is not adapted for shunting aqueous between the anterior
chamber and Schlemm's canal.
[0021] Most of the problems that have developed with current
glaucoma treatment devices and procedures have occurred because
aqueous fluid is drained from inside of the eye to the surface of
the eye. A need exists, then, for a more physiologic system to
enhance the drainage of aqueous fluid from the anterior chamber
into Schlemm's canal. In the vast majority of glaucoma patients,
the resistance problem lies between Schlemm's canal and the
anterior chamber. The canal itself, the collecting channels and the
episcleral venous system all are intact. Enhancing aqueous flow
directly into Schlemm's canal would minimize the scarring that
usually occurs with external filtration procedure since the
internal angle region is populated with a single line of
nonproliferating trabecular cells. Enhancing aqueous flow directly
into Schlemm's canal would minimize hypotony since the canal is
part of the normal outflow system and is biologically engineered to
handle the normal volume of aqueous humor. Enhancing aqueous flow
directly into Schlemm's canal would eliminate complications such as
endophthalmitis and leaks.
[0022] Schlemm's canal may be collapsed in some patients. In those
patients, a structure that maintains patency of the canal may
improve drainage of aqueous flow.
SUMMARY OF THE INVENTION
[0023] The present invention is directed to a novel implant and an
associated surgical method for the treatment of glaucoma in which
the implant device comprises at least one spiral body and/or
grooved body and is placed to divert aqueous humor from the
anterior chamber of the eye into Schlemm's canal, the collector
channels, or the aqueous venous system. The present invention is
further directed to providing a permanent, indwelling shunt to
provide increased egress of aqueous humor from the anterior chamber
to Schlemm's canal, collector channels, or aqueous venous system
for glaucoma management.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIG. 1A is an illustration showing an overhead perspective
view of one embodiment of the present invention, in which the
inventive shunt is comprised of tubular elements extending
bi-directionally within Schlemm's canal.
[0025] FIG. 1B is an overhead view of the embodiment of the present
invention shown in FIG. 1A, with phantom lines detailing the
internal communication between the lumens of the tubular elements
comprising the inventive device.
[0026] FIG. 1C is an illustration showing an overhead perspective
view of one embodiment of the present invention, in which the
inventive shunt is comprised of mesh tubular elements extending
bi-directionally within Schlemm's canal.
[0027] FIG. 1D is an illustration showing an overhead perspective
view of one embodiment of the present invention, in which the
inventive shunt is comprised of solid, porous elements extending
bi-directionally within Schlemm's canal.
[0028] FIG. 1E is an overhead perspective view of another
embodiment of the present invention, with phantom lines detailing
the internal communication between the two proximal lumens and the
single distal lumen of the inventive device.
[0029] FIG. 2 is an illustration showing another embodiment of the
present invention, in which the inventive shunt is comprised of
perforated tubular elements and with an angulated terminal aspect
of the proximal portion.
[0030] FIG. 3A is an illustration showing a perspective of another
embodiment of the present invention in which the inventive shunt is
comprised of elements that are partially tubular and partially open
in their configuration.
[0031] FIG. 3B is an illustration showing a top view of the
embodiment of the present invention in FIG. 3A, with phantom lines
detailing the internal communication of the device.
[0032] FIG. 3C is an illustration showing a side view from the
proximal end of the embodiment of the present invention in FIG.
3A.
[0033] FIG. 3D is an illustration showing a perspective of another
embodiment of the present invention in which the inventive shunt is
comprised of elements that are partially open and trough-like in
their configuration.
[0034] FIG. 4 is an illustration showing another embodiment of the
present invention, in which the inventive shunt is comprised of
distal elements having wicking extensions at their terminal ends,
and in which the proximal portion has a sealed, blunted tip with a
portal continuous with the lumen of the proximal portion, oriented
to face away from the iris when the device is implanted in
Schlemm's canal.
[0035] FIG. 5A is an illustration showing another embodiment of the
inventive shunt in which a portion of the device enters Schlemm's
canal in only one direction and shunts fluid in a non-linear path
from the anterior chamber.
[0036] FIG. 5B is an illustration showing an alternative embodiment
of the inventive shunt in which the entire shunt is placed within
Schlemm's canal but contains a fenestration to maintain fluid
egress of aqueous humor from the anterior chamber to Schlemm's
canal.
[0037] FIG. 5C is an illustration showing a side view of one
embodiment of the present invention, in which the inventive shunt
is comprised of tubular elements, with a proximal portion extending
towards the anterior chamber that is shorter relative to the distal
portions which extend bi-directionally within Schlemm's canal.
[0038] FIG. 5D is an illustration showing an alternative embodiment
of the inventive shunt comprised of a partially open trough-like
element which is placed within Schlemm's canal but contains a
portal to maintain fluid egress of aqueous humor from the anterior
chamber to Schlemm's canal.
[0039] FIG. 5E is an illustration showing an alternative embodiment
of the inventive shunt comprised of a solid, but porous wick-like
element which is placed within Schlemm's canal FIG. 6A is an
illustration showing certain anatomic details of the human eye.
[0040] FIG. 6B is a cross-sectional illustration showing the
anatomic relationships of the surgical placement of an exemplary
embodiment of the present invention.
[0041] FIG. 6C is a cross-sectional illustration showing the
anatomic relationships of the surgical placement of another
exemplary embodiment of the present invention in which the proximal
portion has an angulated terminal aspect with a sealed, blunted tip
with a portal continuous with the lumen of the proximal portion,
oriented to face away from the iris when the device is implanted in
Schlemm's canal.
[0042] FIG. 7 is an illustrative example showing a spiral
configuration body of one embodiment of the invention.
[0043] FIG. 8 is an illustrative example showing a spiral
configuration body of one embodiment of the invention.
[0044] FIG. 9 is an illustrative example showing a spiral
configuration body of one embodiment of the invention.
[0045] FIG. 10. is an illustrative example showing a spiral
configuration body of one embodiment of the invention.
[0046] FIG. 11. is an illustrative example showing a grooved body
of one embodiment of the invention.
[0047] FIG. 12. is an illustrative example showing a spiral
configuration body of one embodiment of the invention having an I
beam cross section.
[0048] FIG. 13. is an illustrative example showing a corkscrew
configuration body of one embodiment of the invention.
[0049] FIG. 14. is an illustrative example showing a bi-directional
implant configuration of one embodiment of the invention.
[0050] FIG. 15. is an illustrative example showing a bi-directional
spiral configuration body within the exemplary eye of one
embodiment of the invention.
[0051] FIG. 16. is an illustrative example showing a laddered
configuration of one embodiment of the invention.
[0052] FIG. 17. is an illustrative example showing a corrugated
configuration of one embodiment of the invention.
[0053] FIG. 18. is an illustrative example showing another
variation of a corrugated configuration of one embodiment of the
invention.
DETAILED DESCRIPTION OF PRESENT INVENTION
[0054] The present invention provides an aqueous humor shunt device
to divert aqueous humor in the eye from the anterior chamber into
Schlemm's canal, a collector channel, or an aqueous venous system
in which the shunt device comprises a distal portion comprising at
least one spiral body and/or grooved body having at least one
terminal aspect sized and shaped to be circumferentially received
within a portion of Schlemm's canal, collector channel, or aqueous
venous system, and a proximal portion having at least one terminal
aspect sized and shaped to be received within the anterior chamber
of the eye, wherein the device permits fluid communication between
the proximal portion in the anterior chamber to the distal portion
in Schlemm's canal, the collector channel, or the aqueous venous
system. Fluid communication can be facilitated by an aqueous humor
directing channel in either the proximal or distal portions, as
described below. Fluid communication can also be facilitated by a
wicking function of the at least one spiral body and/or grooved
body distal portion.
[0055] In some embodiments, the proximal portion also comprises at
least one spiral body and/or grooved body. Therefore, in certain
embodiments, the entire shunt implant device can comprise at least
one spiral body. Alternatively, the spiral body portions can be
affected to or co-extensive with other solid, porous or fenestrated
segments of the distal or proximal portions of the shunt.
[0056] The present invention also provides embodiments of an
inventive shunt implant device comprising at least one spiral body
and/or grooved body of biocompatible material of a size and shape
adapted to be circumferentially received within a portion of
Schlemm's canal wherein the body facilitates the passage of aqueous
humor into Schlemm's canal, the collector channel, or the aqueous
venous system. This embodiment of the device of the present
invention can be produced without the proximal portion of the
previous embodiment extending into the anterior chamber. Certain
embodiments of the spiral body or grooved body can have solid
porous or fenestrated encasings on either or both of the distal
ends or on various portions thereof. An aqueous humor directing
channel within the spiral body or grooved body can facilitate the
passage of aqueous humor from the anterior chamber into Schlemm's
canal, the collector channel, or the aqueous venous system. Fluid
communication can also be facilitated by a wicking function of the
spiral body or grooved body, for example.
[0057] The spiral body or grooved body can extend in a
unidirectional or bi-directional orientation within Schlemm's
canal. The spiral body can be tightly or loosely wound with a pitch
of 1 to 20 turns per 1/1000 inch. Pitch is the measurement between
peak to peak coils. For example, if the pitch is one wire width,
the pitch is closed and the wires will touch. The pitch of the body
can also be adjusted by manual force depending upon the needs of
the patient along any particular section of any length. The device
can also comprise two or more parallel spiral bodies or grooved
bodies for insertion into Schlemm's canal.
[0058] In certain embodiments, the spiral body can have a length of
from 1.0 mm to 40.0 mm and an outer diameter of between about 0.1
to about 0.5 mm. The invention contemplates many different
configurations for an aqueous humor directing channel, provided
that each assists in channeling aqueous humor from the anterior
chamber to Schlemm's canal, the collector channel, or the aqueous
venous system, such as by providing a lumen, trough, wick or
capillary action. For example, the aqueous humor directing channel
can be a fully enclosed lumen, a partially enclosed lumen, or a
trough-like channel that is at least partially open.
[0059] In preferred embodiments of the present invention the
aqueous directing channel is defined within the spiral body.
Alternatively, the aqueous directing channel may be defined within
the grooved body. Furthermore the gaps between the coils,
corkscrew, or spring of the spiral body serve to divert aqueous
humor laterally outside the directing channel, as a function of
pitch. Alternatively, the indentation of the grooved body may also
serve to divert aqueous humor laterally outside the directing
channel.
[0060] In some embodiments, the distal portion and the spiral body
can be co-extant, such that the spiral body is partially mounted
within the distal portion.
[0061] In some embodiments, the spiral body or the grooved body can
be made of metal, such as stainless steel, nitinol, or titanium,
and can be further coated in a polymer such as silicone or a
fluorinated polymer (PTFE-FEP). Such materials of construction can
be further treated with a drug or therapeutic agent, such as an
antibiotic, to elute therefrom.
[0062] In some embodiments, the spiral body or the grooved body may
also comprise a cap on at least one longitudinal end thereof to
facilitate insertion within Schlemm's canal. The cap is preferably
a rounded and/or elongated, blunt tip element attached to the
terminal aspect of the spiral body or the grooved body. The cap
further provides an endpoint for insertion of a guide wire through
the length of the spiral for improved insertion into Schlemm's
canal as described more fully below.
[0063] As used herein, the terms "shunt", "shunt device", and
"device" are synonymous with the inventive indwelling shunt
implant.
[0064] Therefore, in one embodiment of the present invention, a
shunt implant device with at least one spiral body and/or grooved
body is provided. For example, the spiral body of the shunt may be
coil, spring, corkscrew, patent or a combination thereof and may
have a cross-section shape which includes but is not limited to
round, oval, triangular, rectangular, square, polygonal, or oblong,
which may be solid, hollow, porous, or a combination thereof. In
another example, the entire shunt implant device may be coil,
spring, corkscrew or a combination thereof. In yet another example,
the shunt implant device, which comprises at least one spiral body
and/or grooved body, may further comprise at least one solid,
porous, or fenestrated portion. Alternatively the surface of the
implant device may be grooved in any pattern or shape to channel
the flow of fluid in the eye.
[0065] It is contemplated that one of ordinary skill in the art,
may combine the spiral body or grooved body of the device in any
manner available in the art such as welding, adhesives, molding,
heating, bolting, screwing, stretching, indenting, or bending. It
is also contemplated that any permutations of coil, spring,
corkscrew, tubular, grooved, patent, hollow, solid, porous, curved,
angular, or linear sections may be employed to achieve the shunt
implant device of the present invention.
[0066] The invention contemplates that a solid monofilament or
braided polymer, such as proline, can also be inserted into
Schlemm's canal, the collector channel, or the aqueous venous
system in association with the spiral body and/or grooved body to
provide a wicking function to facilitate the passage of aqueous
humor to Schlemm's canal, the collector channel, or the aqueous
venous system. Such a wicking extension can also be grooved or
fluted along any portion of the length thereof, so as to be
multi-angular or star-shaped in cross-section.
[0067] In another embodiment, at least one retaining flap or any
other design which allows for suture handling is provided on the
shunt device. In another embodiment, the invention contemplates at
least one flap, arrowhead-like extension, grove, or hook design on
the device which will retain, attach, or stabilize the device
within the Schlemm's canal, collector channel, or aqueous venous
system. The design may also be any combination of a flap,
arrowhead-like extension, grove, or hook design. The placement of
these designs may be on any location of the device which will
stabilize the device in the Schlemm's canal, collector channel, or
aqueous venous system. For example, the retaining, attaching, or
stabilizing design may be placed at all ends of the device or one
end of the device.
[0068] In another embodiment, the device may include a one-way
valve for controlling the aqueous flow direction. For example, any
one-way valve which prevents blood reflux from the venous system
into the eye may be used.
[0069] The present invention also provides methods of delivery and
use of the shunt devices. One embodiment of the present invention
is directed to a surgical method to divert aqueous humor from the
anterior chamber of the eye into Schlemm's canal, the collector
channel, or the aqueous venous system with a device that is
implanted to extend from within the anterior chamber to Schlemm's
canal, the collector channel, or the aqueous venous system. The
portion of the device extending into Schlemm's canal can be
fashioned from a flexible material capable of being received within
a portion of the radius, curvature, and diameter of Schlemm's
canal, the collector channel, or the aqueous venous system.
[0070] In one embodiment of the present invention, the pitch of the
spiral body is alterable at selected positions along the length
thereof to provide sufficient egress of aqueous humor at desired
positions depending upon the needs of the patient.
[0071] In one embodiment, the device and methods provided may be
delivered in any known method to those skilled in the art. For
example, non-limiting methods for delivery includes, but are not
limited to, manual insertion into Schlemm's canal or assistance
with a guide wire, suture, or flexible rod. In one method of the
invention a guide wire is inserted through the spiral body or
grooved body and against the interior of a distal cap attached to
the terminal aspect of the spiral body or grooved body. The guide
wire and spiral body are then inserted into Schlemm's canal. After
insertion, the guide wire is withdrawn and the conjunctival flap is
closed. It is apparent that various embodiments of the present
invention will be adapted for uni-direction or bi-directional flow
of aqueous humor through Schlemm's canal.
[0072] In one embodiment, an implant device comprising a spring and
coil portion, as defined by greater or lesser pitch of the spiral
body, respectively, which is attached at the coiled portion in
parallel to another spring and coil portion at the coiled portion.
This provides a flexible bi-directional shunt device. Again, the
distal aspects of the spiral spring portions can comprise a ball or
capped end which is atraumatic upon insertion into Schlemm's canal.
In a sub-embodiment, the ball or capped end of the implant device
may be pushed with a guidewire or rod into Schlemm's canal.
[0073] In another embodiment, an implant device comprising a
tubular-spiral-tubular configuration, wherein the spiral body
portion wraps substantially around the Schlemm's canal. In a
sub-embodiment, this implant device may comprise a ball or capped
end and can be delivered using a guide wire, suture, plastic rod,
or a combination thereof.
[0074] One embodiment of the present invention is illustrated in
FIG. 1A, in which the shunt device 100 is shown in a side view. The
shunt device 100 of this embodiment is comprised of two portions, a
proximal portion 10 which joins a distal portion 25. The proximal
portion 10 and distal portion 25 shown create an enclosed tubular
channeling structure. The total length of the distal portion 25 may
be between about 1 and 40 mm, preferably about 6 mm. The same
embodiment of the present invention is illustrated with phantom
lines showing the internal fluid communication path in FIG. 1B. The
lumen or channeling space defined by the walls of the proximal
portion 10 and the distal portion(s) 25 are continuous at their
junction at the distal portion portal 20. All or parts of the
device may be solid, coiled, porous, hollow, corkscrewed, grooved,
angular, patent, tubular, trough-like, fenestrated, curved or
pre-curved.
[0075] An alternate embodiment of the present invention is shown in
FIG. 1C, in which the shunt device 100 is comprised of two luminal
mesh elements, with a proximal portion 10 which joins a distal
portion 25. Yet another embodiment of the present invention is
shown in FIG. 1D, in which the shunt device 100 is comprised of two
solid, porous elements which may provide wick-like fluid
communication therethrough, with a proximal portion 10 which joins
a distal portion 25.
[0076] An alternate embodiment of the present invention is shown in
FIG. 1E, in which the shunt device 100 is comprised of a proximal
portion 10 having two lumens therein terminating in proximal
portion portals 18. The distal portion 25 shaped and sized to be
received within Schlemm's canal extends in either direction having
separate lumens traversing therethrough from each of the distal
portion portals 20.
[0077] Other examples of embodiments of the present invention are
shown in FIGS. 2-5D. FIG. 2 shows an embodiment of the inventive
shunt in which the device 100 is tubular and fenestrated (15, 30)
in its configuration, with an acute (<90.degree.) angle of
junction between the proximal portion 10 and the plane defined by
the distal portion 25. Such fenestrations (15, 30) may be placed
along any portion of the device 100 to facilitate the passage of
fluid therethrough, but are particularly directed towards the
collecting channels of the eye. FIG. 2 further shows an alternate
embodiment of the present invention in which the terminal aspect 16
of the proximal portion is angulated toward the iris 40 with
respect to the main axis of the proximal portion 10, with the
portal 18 of the proximal portion directed toward free the iris 40.
In alternate embodiments as shown in FIG. 6C, the portal 18 of the
proximal portion 16 is directed away from the iris 40.
[0078] FIG. 3A shows an embodiment of the inventive shunt in which
a portion of the channeling device is enclosed and tubular in
configuration at the junction of the proximal portion 10 and the
distal portion 25, but where the distal portion 10 is a trough-like
channel. The distal portion portal 20 is also shown. The invention
contemplates that any portion of the device 100 can be
semi-tubular, open and trough-like, or a wick-like extension.
Tubular channels can be round, coil, spring, ovoid, corkscrewed,
grooved, patent, porous, triangular, rectangular, square,
polygonal, or any other enclosed geometry. Preferably the
non-tubular trough-like aspects are oriented posteriorly on the
outer wall of the canal to facilitate aqueous humor drainage to the
collecting channels of the eye, as shown in FIG. 3A.
[0079] FIG. 3B shows an overhead view of the embodiment of the
inventive shunt of FIG. 3A, further detailing the relationship
among the proximal portion 10 and the distal portion 25. The
aqueous humor directing channel is shown in dashed lines. FIG. 3C
shows a proximal view of the embodiment of the inventive shunt of
FIG. 3A, further detailing the relationship among the proximal
portion 10 and the distal portion 25.
[0080] FIG. 3D shows another embodiment of the inventive shunt in
which the structure of the device 100 comprises an aqueous humor
directing channel that is both open and curved in a continuous
trough-like configuration along the proximal portion 10 and the
distal portion 25. The distal portion portal 20 is also an open
trough-like channel.
[0081] FIG. 4 shows another embodiment of the inventive shunt with
the addition of aqueous humor-wicking extensions 32 which are
either continuous with, or attached to the terminal aspects of the
distal portion 25. The wicking extensions 32 can be fashioned from
a monofilament or braided polymer, such as proline, and preferably
have a length of 1.0 mm to 16.0 mm. Furthermore, the proximal
portion 10 is curved with a sealed, blunted tip 16 and contains a
portal 18 in fluid communication with the lumen of the proximal
portion and oriented to face away from the iris when the shunt
device 100 is implanted in its intended anatomic position. The
shunt device 100 can also help to maintain the patency of Schlemm's
canal in a stenting fashion.
[0082] FIG. 5A shows another embodiment of the inventive shunt in
which the proximal portion 10 joins a single, curved distal portion
25 in a "V-shaped," tubular configuration. The embodiment shown in
FIG. 5A can also have a portal (not shown) in the distal portion 25
adjacent to the junction with the proximal portion 10 in order to
facilitate bi-directional flow of fluid within the canal.
Fenestrations and non-tubular, trough-like terminal openings are
contemplated in all embodiments of the invention, and these
fenestrations and openings may be round, ovoid, or other shapes as
needed for optimum aqueous humor channeling function within the
anatomic spaces involved.
[0083] FIG. 5B shows another embodiment of the inventive shunt in
which the body or device 100 comprises only a single, curved distal
portion 25 which contains a distal portion portal 20 oriented
towards the anterior chamber to allow egress of aqueous humor from
the anterior chamber to Schlemm's canal. The body of this device
can have a length of about 1.0 mm to 40 mm, preferably about 6 mm.
The external diameter can be about 0.1 mm to 0.5 mm, or about 0.3
mm.
[0084] FIG. 5C shows another embodiment of the inventive shunt in
which the device 100 comprises a bi-directional tubular distal
portion 25 which is intersected by a proximal portion 10 which is
short in length relative to the distal portion 25 and is directed
towards the anterior chamber.
[0085] FIG. 5D shows still another embodiment of the inventive
shunt in which the device 100 comprises a bi-directional,
trough-like, curved distal portion 25 for insertion into Schlemm's
canal, which contains a distal portion portal 20 oriented to allow
egress of aqueous humor from the anterior chamber, wherein the
trough-like distal portion 25 is oriented to open toward the
collecting channels to facilitate the egress of aqueous humor.
[0086] FIG. 5E shows another embodiment of the inventive shunt in
which the device 100 comprises a bi-directional, solid distal
portion 25 for insertion into Schlemm's canal to facilitate the
egress of aqueous humor from the canal to the collecting channels
in a wicking capacity. The solid distal portion 25 can be porous or
non-porous.
[0087] The present invention contemplates that the illustrative
examples in FIGS. 1-5 may also include at least one spiral body
and/or grooved body such as a coil, spring, corkscrew, patent or
combination thereof configuration. The present invention also
contemplates a device comprising at least one spiral body and/or
grooved body in linear, curved, Y-, L-, V-, or T-, shaped device.
For example, the entire device may be a coil, spring, or
combination thereof in a linear, curved, Y-, L-, V-, or T-, shaped
device configuration. In another example, the device may comprise a
coil section followed by a spiral body or grooved body.
[0088] As the inventive device is an implant, it can be fabricated
from a material that will be compatible with the tissues and fluids
with which it is in contact. It is preferable that the device not
be absorbed, corroded, or otherwise structurally compromised during
its in situ tenure. Moreover, it is equally important that the eye
tissues and the aqueous remain non-detrimentally affected by the
presence of the implanted device. A number of materials are
available to meet the engineering and medical specifications for
the shunts. In the exemplary embodiments of the present invention,
the shunt device is constructed of a biologically inert, flexible
material such as silicone or similar polymers. Alternate materials
might include, but are not limited to, thin-walled Teflon,
polypropylene, other polymers or plastics, metals, or some
combination of these materials. The shunt device may be constructed
as either porous or solid in alternate embodiments. The material
can contain a therapeutic agent deliverable to the adjacent
tissues.
[0089] In the embodiments shown in FIGS. 1-4, the proximal portion
10 joins the distal portion(s) 25 at an angle sufficient to allow
the placement of the proximal portion 15 within the anterior
chamber of the eye when the distal portion 25 is oriented in the
plane of Schlemm's canal. The proximal portion 10 is preferably of
sufficient length, about 0.1 to 3.0 mm or about 2.0 mm, to extend
from its junction with the distal portion 25 in Schlemm's canal
towards the adjacent space of the anterior chamber. While many
geometries can be used for channeling aqueous humor, the diameter
or width of the proximal portion 10 can be sized to yield an
internal diameter of between about 0.1 and 0.5 mm, preferably 0.20
mm, for a tubular or curved shunt, or a comparable maximal width
for a shunt with a multiangular configuration. In other
embodiments, the proximal portion is a non-luminal, non-trough-like
wicking, coiled, spring, patent, grooved, or corkscrewed extension
that provides an aqueous humor directing channel along the length
thereof.
[0090] Because the nature of the iris 40 is such that it tends to
comprise a plurality of rather flaccid fimbriae of tissue, it is
desirable to avoid said fimbriae from being drawn into the lumen of
an implant, thus occluding the shunt device. Therefore, the
proximal portion 10 may contain a plurality of fenestrations to
allow fluid ingress, arranged to prevent occlusion by the adjacent
iris. Alternately, the proximal portion 10 may comprise only a
proximal portion portal 18 in the form of a fenestration oriented
anteriorly to provide continuous fluid egress between the anterior
chamber of the eye and the directing channel of the shunt. Said
fenestrations may be any functional size, and circular or
non-circular in various embodiments of the present invention. In
addition, a porous structural material can assist in channeling
aqueous humor, while minimizing the potential for intake of
fimbriae.
[0091] Furthermore, the proximal portion 10 may be positioned
sufficiently remote from the iris 40 to prevent interference
therewith, such as by traversing a more anterior aspect of the
trabecular meshwork into the peripheral corneal tissue. In yet
another possible embodiment, as shown in FIG. 6C, the device 100
may comprise a proximal portion 10 in which the terminal aspect of
said proximal portion 10 is curved or angled toward the iris 40,
and with a blunted, sealed tip 16 and a portal 18 oriented
anteriorly to face away from the underlying iris 40. Such a
configuration would tend to decrease the possibility of occlusion
of the shunt device by the iris 40.
[0092] The device 100 may contain one or more unidirectional valves
to prevent backflow into the anterior chamber from Schlemm's canal.
The internal lumen for an enclosed portion of the device or the
internal channel defined by the edges of an open portion of the
device communicates directly with the inner lumen or channel of the
distal portion at the proximal portion portal 20.
[0093] The distal portion 25 may have a pre-formed curve to
approximate the 6.0 mm radius of Schlemrn's canal in a human eye.
Such a pre-formed curvature is not required when flexible material
is used to construct the shunt device 100. The distal portion 25
may be of sufficient length to extend from the junction with the
proximal portion 10 through any length of the entire circumference
of Schlemm's canal. Embodiments having a distal portion 25 that
extends in either direction within Schlemm's canal can extend in
each direction about 1.0 mm to 20 mm, or about 3.0 mm, to permit
circumferential placement through Schlemm's canal. The diameter of
width of the distal portion 25 can be sized to yield an outer
diameter of between about 0.1 and 0.5 mm, or about 0.3 mm, for a
tubular or curved shunt, or a comparable maximal width for a shunt
with a multiangular configuration. The distal portion 25 may
contain a plurality of fenestrations to allow fluid egress,
arranged to prevent occlusion by the adjacent walls of Schlemm's
canal. In other embodiments, the distal portion is a non-luminal,
non-trough-like wicking extension that provides an aqueous humor
directing channel along the length thereof.
[0094] In the exemplary embodiments of the present invention, the
shunt device may be either bi-directional, with the distal portion
of the implant intersecting with the proximal portion in a
"T-shaped" junction as shown in FIGS. 1A-1E, 2, 3A-3D, 4 and 5C, or
unidirectional, with a "V-shaped" junction of the proximal and
distal shunt portions, as shown in FIG. 5A. A bi-directional shunt
device can have a distal portion that is threaded into opposing
directions within Schlemm's canal, the collector channel, or the
aqueous venous system. In the case of the uni-directional shunt,
only the distal shunt portion is placed within Schlemm's canal, the
collector channel, or the aqueous venous system. In these exemplary
embodiments, "non-linear fluid communication" means that at least
some portion of the shunt through which fluid passes is not in a
straight line. Examples of non-linear shunts are the above
described bi-directional "T" shapes, and the uni-directional "V"
shapes, or shunts having two channel openings which are not in
straight alignment with each other.
[0095] The surgical anatomy relevant to the present invention is
illustrated in FIG. 6A. Generally, FIG. 6A shows the anterior
chamber 35, Schlemm's canal 30, the iris 40, cornea 45, trabecular
meshwork 50, collecting channels 55, episcleral veins 60, pupil 65,
and lens 70. FIG. 6B illustrates the surgical placement of the
exemplary embodiment of the present invention, with the relevant
anatomic relationships. It should be noted that the inventive
device is designed so that placement of the distal portion 25
within Schlemm's canal 30 results in an orientation of the proximal
portion 10 within the anterior chamber 35 within the angle defined
by the iris 40 and the inner surface of the cornea 45. Therefore,
if the plane defined by Schlemm's canal is defined as zero degrees,
the proximal portion 10 can extend therefrom at an angle of between
about +60 degrees towards the cornea 45 or -30 degrees toward the
iris 40, more preferably in the range of 0 to +45 degrees. This
range may vary in individuals having a slightly different location
of Schlemm's canal 30 relative to the limbal angle of the anterior
chamber 35.
[0096] In another embodiment illustrated by FIG. 7, the shunt
device is configured as a linear spring having a proximal end 10
for insertion into the anterior chamber and a distal end 25 which
is placed in Schlemm's canal wherein at least some of the coils of
the spring have an opening 20 between adjacent coils to permit
fluid flow. The distal end may be terminated in a ball shape 80 or
may be left an open lumen. The proximal end contains an open lumen
18. The coils 64 of the spring can themselves form the ball end 80
of the shunt by progressively tightening the coils as show in FIG.
8. In yet another embodiment, the devices of the present invention
avoid blocking outflow to the collector channel is provided.
[0097] FIG. 10 shows a bidirectional shunt embodiment employing a
dual lumen coil spring. This embodiment would be wound from a
continuous piece of suitable coil forming material such as nitinol
or stainless steel wire or from suitable plastics or shape memory
materials as are well known in the art. To form the ball the coils
are wound progressively tighter and finished so that the coil
material has reduced potential to snag tissue as it is inserted
into Schlemm's canal.
[0098] In another embodiment as exemplified by FIG. 11, the shunt
is a solid body having transverse grooves 90 and/or ridges 75 on
its external surface for channeling aqueous fluid. Alternatively,
the grooves can be spiral in nature as shown in FIG. 12. It
preferred that these embodiments terminated in a rounded end 80 to
reduce the potential for snagging tissues upon insertion.
[0099] In yet another embodiment as exemplified by FIG. 13 the
shunt can be a corkscrew or helical shape with ridges 75 defining a
groove 90 through which fluid flows. The structure of the shunt in
this embodiment can be constructed of material having any type of
cross section, although an I beam cross section is most preferred
because of the defined ridge 75 and subsequent groove 90 it
creates.
[0100] A preferred embodiment is show in FIG. 14. In this
embodiment, the shunt device 100 is configured with one distal
portion 10 which is tubular to provide a shunting functionality and
at least two proximal portions 25 which provide an anchoring
function to stabilize the overall implant device, in addition to
providing fluid communication from the anterior chamber to
Schlemm's Canal, collector channel, or aqueous venous system. In
this embodiment it is most preferred that the proximal end 10 is a
dual lumen silicone tube in which each lumen is joined to a second
open structured tube 135 either by friction fitting the open
structured tube 135 into or around the lumen of the silicone tube
or via bonding the two sections together. Alternatively, the device
can be designed as three separate components comprising a shunt for
bypassing fluid from the anterior chamber into Schlemm's canal and
at least one stent section for maintaining the patency of Schlemm's
canal. FIG. 15 shows a plurality of devices 100 according to the
present invention in place inside of Schlemm's Canal.
[0101] In yet another embodiment as exemplified by FIG. 16, the
shunt is constructed in a ladder configuration having side rails
115 and shaped transverse members 120 in which the transverse
members extend above or below the side rails in an alternation
fashion forming a lumen 110.
[0102] In another embodiment as exemplified by FIG. 17, the shunt
can be corrugated with a plurality of troughs and ridges having at
least one aperture 110 through a side 111 of the corrugations. The
corrugation can be either a squared form as shown or can be rounded
or any other configuration which allows for creating of space for
fluid flow.
[0103] In another embodiment as exemplified in FIG. 18, the shunt
can be created from a plurality of corrugated strips 107 having
troughs 106 and ridges 109 which are offset from each other such
that the ridge of one strip is positioned adjacent to the trough of
the next corrugated strip thereby creating a plurality of openings
108 through which aqueous fluid can flow.
[0104] Devices of the present invention can readily be made by
known extrusion, molding or coil forming processes. The devices can
be made as one piece or in subcomponents and mechanically fastened
or bonded during assembly or during the insertion.
[0105] In another embodiment, the devices of the present invention
enhance the aqueous flow through the Schlemm's canal, the collector
channel, or the aqueous venous system are provided. In yet another
embodiment, the devices of the present invention prevents
collapsing of the Schlemm's canal, collector channel, or aqueous
venous system.
[0106] In another embodiment of the present invention, the device
provided may be used alone or in combination with available eye
shunts. The present invention can be used in conjunction with a
surgical implant device, such as a unidirectional or bi-directional
shunt device described in U.S. Pat. No. 6,450,984, incorporated by
reference herein in its entirety, used to divert aqueous humor in
the eye from the anterior chamber into Schlemm's canal. Such a
device comprises a distal portion having at least one terminal
aspect sized and shaped to be circumferentially received within a
portion of Schlemm's canal, and a proximal portion having at least
one terminal aspect sized and shaped to be received within the
anterior chamber of the eye, wherein the device permits fluid
communication between the proximal portion in the anterior chamber
to the distal portion in Schlemm's canal. Such a device, for
example, can have a distal portion of between about 1 mm and 40 mm
in length. The diameter of the distal portion, for example, can be
between about 0.1 mm to 0.5 mm.
[0107] In one embodiment of the present invention, the device may
include porous regions, so that new blood vessel growth occurs into
pores, channels, or interstices of the porous material.
[0108] In another embodiment, the biocompatibilty of the device may
be improved (i.e., modified) with chemicals so that the subsequent
healing response of tissue in association with the material forming
the regions is altered once the glaucoma shunt is implanted. The
alteration in healing response can be a reduction in inflammatory
response typically seen with polymeric materials, and includes a
reduced presence of macrophages and foreign body giant cells. The
chemical modifications may include the covalent interaction of the
chemical species with polymer. In addition, the chemical
modifications include the absorption of the applied chemical
species into the polymers. These chemical modifications include the
use of proteins and peptides with known affects on cellular
function, such as the reduction in inflammation, reduction in
fibrous capsule formation by inhibiting the proliferation of cells
found in developing fibrous capsules, or inhibition of
extracellular matrix protein synthesis by cells in the fibrous
capsule.
[0109] Further, a "denucleated" material reduces the inflammatory
response of tissue surrounding the implant, and increases
neovascularization (i.e., increase in new blood vessels) in tissue
surrounding the material. That is, the glaucoma shunt may comprise
a material selected from the group consisting of denucleated
polytetrafluoroethylene (ePTFE), denucleated polyurethane, and
denucleated elastomeric silicone, such that at least 60% of air
trapped within the material is removed. Denucleation is a process
which removes air trapped within the material.
[0110] Devices of the present invention may also be coated with a
hydrophilic substance to ease insertion. Appropriate coatings
include but are not limited to hydroxy-methyl acrylate,
hydroxy-ethyl methacrylate or Poly Vinyl Alcohol (PVA). One of
skill in the art will recognize that any hydrophilic coating
suitable for use on an implanted medical device.
[0111] It is also appreciated that the devices and methods of the
present invention may be carried out ab externo or ab interno. In
one embodiment, the device used comprises a metal wire such as
stainless steel wire, e.g. 304 grade. In a sub-embodiment, the
device comprises a rectangular cross section, of for example,
1.5.times.3 with a pitch of 0.006. In another sub-embodiment, the
outer diameter of the device was constant at from about 0.001 in.
to about 0.1 inch. In another example, outer diameter of the device
is constant about 0.010 in.
[0112] An exemplary surgical procedure to insert the device may
require an approach through a conjunctival flap. A partial
thickness scleral flap is then created and dissected half-thickness
into clear cornea. The posterior aspect of Schlemm's canal is
identified and the canal is entered posteriorly. The anterior
chamber may be deepened with injection of a viscoelastic and a
miotic agent. The proximal portion of the shunt is then inserted
through the inner wall of Schlemm's canal and trabecular meshwork
into the anterior chamber within the angle between the iris and the
cornea. In some cases, an incision may be needed from Schlemm's
canal through the trabecular meshwork into the anterior chamber to
facilitate passage of the proximal portion therethrough. One arm of
the distal portion of the shunt device is grasped and threaded into
Schlemm's canal. In a similar fashion, the other arm of the distal
portion of the shunt device (when present) is inserted into
Schlemm's canal in the opposing direction from the first. The
scleral flap and conjunctival wound are closed in a conventional
manner.
[0113] While the above-described embodiments are exemplary, the
invention contemplates a wide variety of shapes and configurations
of the shunt to provide fluid communication between the anterior
chamber and Schlemm's canal, the collector channels, or the aqueous
venous system. The above-described embodiments are therefore not
intended to be limiting to the scope of the claims and equivalents
thereof.
EXAMPLES
[0114] Human cadaver eyes were used for Examples I-III. The shunt
device used in Examples I-III comprised spiral body having a
proximal end that starts with a closed-pitch coil. After 3 mm, the
pitch is increased to get a traditional open-pitch spring
configuration. The distal end has a ball end. The wire used for the
spiral body was a stainless steel wire, 304 grade, with a
rectangular cross section, 1.5.times.3 with a pitch of 0.006. The
outer diameter was constant at 0.010 in. The total length of the
device was 12 mm.
[0115] The surgical procedure of the following examples, to insert
the device utilized an approach through a conjunctival flap. A
partial thickness scleral flap is created and dissected
half-thickness into clear cornea. The posterior aspect of Schlemm's
canal is identified and the canal is entered posteriorly. The
anterior chamber may be deepened with injection of a viscoelastic
and a miotic agent. The proximal portion of the shunt is then
inserted through the inner wall of Schlemm's canal and trabecular
meshwork into the anterior chamber within the angle between the
iris and the cornea. In some cases, as incision may be needed from
Schlemm's canal through the trabecular meshwork into the anterior
chamber to facilitate passage of the proximal portion therethrough.
One arm of the distal portion of the shunt device is grasped and
threaded into Schlemm's canal. In a similar fashion, the other arm
of the distal portion of the shunt device (when present) is
inserted into Schlemm's canal in the opposing direction from the
first. The scleral flap and conjunctival wound are closed in a
conventional manner.
Example I
[0116] Eye#1: The posterior aspect of Schlemm's canal was
identified and the canal was entered posteriorly. After the
proximal portion of the shunt is inserted through the inner wall of
Schlemm's canal and trabecular meshwork into the anterior chamber
within the angle between the iris and the cornea, the ball end of
the spring was introduced into the Schlemm's canal. The proximal
end of the device was introduced into the anterior chamber.
Finally, blue dye was introduced into the anterior chamber under a
constant low pressure of approximately 16 mm Hg. After a few
minutes, a blue coloration was observed along the entire length of
the coil prototype. Schlemm's canal was unroofed on the other side
of the surgical side, and no dye flow was observed. The canal was
unroofed at the tip of the coil, and a blue coloration was
present.
Example II
[0117] Eye#2: The ball end of the spring was introduced into
Schlemm's canal, and the entire length of the device was fully
pushed into one direction of the canal using a viscocannalastomy
needle. A bi-directional shunt as described in U.S. Pat. No.
6,450,984 was placed conventionally within the other side of
Schlemm's canal of the implantation site; the other leg of the
shunt was cut in order to be introduced into Schlemm's canal and to
be "connected" to the proximal end of the spring. Finally, green
dye was introduced into the anterior chamber under a constant low
pressure of approximately 16 mm Hg. After a few minutes, a green
coloration appeared on the coil side, throughout the entire length
of the coil, and a limited coloration appears distally to the end
of the device. At the location of implantation and the distal end
of the traditional shunt, no coloration was present. The eye was
then cut in half to expose the trabecular mesh: the spiral body did
not "recoil" and the spring portion stayed "opened". The spiral
body covered about a 120.degree. portion of the Schlemm's canal.
Schlemm's canal outer diameter is about 12 mm, or 38 mm
circumference, and the device was 12 mm long.
Example III
[0118] Eye #3: Once the canal was unroofed, the spiral body was set
in place and the site of implantation closed. Dye was infused, but
no coloration appeared in the venous outflow. Pressure measurement:
An attempt was made to take pressure measurements using the WPI
micropressure system. The system was initialized properly but the
measurements seemed out-of-range once the sensor was placed into
the anterior chamber.
[0119] Examples I-III resulted in IOP lowering. The devices of the
present invention were easy to refine and implement. The devices
has the ability to be used in conjunction with the '984 or '858
shunt to potentially improve the efficacy of '984 or '858 shunt or
could be developed into a standalone '984 or '858 shunt type
implant.
[0120] Thus, while there have been shown and described and pointed
out fundamental novel features of the present invention as applied
to preferred embodiments thereof, it will be understood that
various omissions and substitutions and changes in the form and
details of the devices illustrated, and in their operation, and in
the method illustrated and described, may be made by those skilled
in the art without departing from the spirit of the invention as
broadly disclosed herein.
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