U.S. patent application number 13/724259 was filed with the patent office on 2013-11-21 for ocular implant with double anchor mechanism.
This patent application is currently assigned to GLAUKOS CORPORATION. The applicant listed for this patent is GLAUKOS CORPORATION. Invention is credited to David S. Haffner, Barbara A. Niksch, Gregory T. Smedley, Hosheng Tu.
Application Number | 20130310930 13/724259 |
Document ID | / |
Family ID | 23106620 |
Filed Date | 2013-11-21 |
United States Patent
Application |
20130310930 |
Kind Code |
A1 |
Tu; Hosheng ; et
al. |
November 21, 2013 |
OCULAR IMPLANT WITH DOUBLE ANCHOR MECHANISM
Abstract
The invention relates generally to medical devices and methods
for the treatment of ocular disorders. An ocular implant having an
inlet portion with a first anchor and an outlet portion with a
second anchor is provided. The first anchor is configured to be
positioned adjacent eye tissue, for example, within an anterior
chamber of an eye, and the second anchor is configured to be
positioned within a physiological outflow pathway of the eye. The
implant, when implanted in the eye, is configured to conduct fluid
from the anterior chamber to the physiological outflow pathway.
Desirably, the second anchor is deployable and is configured to
secure the implant within the physiological outflow pathway. Also
provided is an ocular treatment method which involves implanting
the implant to secure the implant within the physiological outflow
pathway by deploying the second anchor.
Inventors: |
Tu; Hosheng; (Newport Coast,
CA) ; Smedley; Gregory T.; (Irvine, CA) ;
Niksch; Barbara A.; (Laguna Niguel, CA) ; Haffner;
David S.; (Mission Viejo, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
GLAUKOS CORPORATION |
Laguna Hills |
CA |
US |
|
|
Assignee: |
GLAUKOS CORPORATION
Laguna Hills
CA
|
Family ID: |
23106620 |
Appl. No.: |
13/724259 |
Filed: |
December 21, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11860785 |
Sep 25, 2007 |
8337445 |
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13724259 |
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11255625 |
Oct 21, 2005 |
7273475 |
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11860785 |
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10139800 |
May 3, 2002 |
7094225 |
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11255625 |
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60288325 |
May 3, 2001 |
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Current U.S.
Class: |
623/6.14 |
Current CPC
Class: |
A61F 9/00781 20130101;
A61F 2/16 20130101; A61K 9/0048 20130101 |
Class at
Publication: |
623/6.14 |
International
Class: |
A61F 2/16 20060101
A61F002/16 |
Claims
1. A method of treating an ocular disorder, comprising: providing
an implant comprising an inlet portion having a first anchor and an
outlet portion having a second anchor; implanting the implant in
tissue of an eye such the implant conducts fluid from an anterior
chamber of the eye to a physiological outflow pathway of the eye,
said implanting comprising: positioning the first anchor adjacent
eye tissue within the anterior chamber; positioning the second
anchor within the physiological outflow pathway; and deploying the
second anchor such that the second anchor secures the implant
within the physiological outflow pathway.
2. The method of claim 1, wherein positioning the first anchor
comprises positioning at least one flexible wing of the first
anchor adjacent the eye tissue.
3. The method of claim 1, wherein positioning the first anchor
comprises positioning a flexible rim of the first anchor adjacent
the eye tissue.
4. The method of claim 1, wherein positioning the second anchor
comprises positioning at least one expandable rib of the second
anchor within the physiological outflow pathway.
5. The method of claim 1, wherein deploying the second anchor
comprises actuating a toggle mechanism that causes the second
anchor to expand within the physiological outflow pathway.
6. The method of claim 5, wherein actuating a toggle mechanism
comprises turning a pin that extends into the implant to deploy a
rib of the second anchor in the physiological outflow pathway.
7. The method of claim 6, wherein turning a pin that extends into
the implant comprises positioning at least one opening of a hollow
portion of the pin such that the at least one opening is in fluid
communication with the physiological outflow pathway to allow flow
of fluid from the anterior chamber to the physiological outflow
pathway.
8. The method of claim 1, wherein deploying the second anchor
comprises actuating a pop-rivet mechanism that causes the second
anchor to expand within the physiological outflow pathway.
9. The method of claim 8, wherein actuating the pop-rivet mechanism
comprises pulling a rod that extends into said implant to deploy a
rib of the second anchor in the physiological outflow pathway.
10. The method of claim 1, wherein the physiological outflow
pathway comprises Schlemm's canal.
11. The method of claim 10, wherein the eye tissue comprises
trabecular meshwork.
12. An implant for treating an ocular disorder, comprising: an
inlet portion comprising a first anchor configured to be positioned
adjacent eye tissue within an anterior chamber of an eye; an outlet
portion comprising a second anchor configured to be positioned
within a physiological outflow pathway of the eye; the implant,
when implanted in the eye, being configured to conduct fluid from
the anterior chamber to the physiological outflow pathway; wherein
the second anchor is deployable and is configured to secure the
implant within the physiological outflow pathway.
13. The implant of claim 12, wherein the first anchor comprises at
least one flexible wing.
14. The implant of claim 12, wherein the first anchor comprises a
flexible rim.
15. The implant of claim 12, wherein the second anchor comprises at
least one expandable rib.
16. The implant of claim 12, wherein the implant further comprises
a deployment mechanism that causes the second anchor to expand
within the physiological outflow pathway.
17. The implant of claim 16, wherein the deployment mechanism
comprises a toggle mechanism.
18. The implant of claim 16, wherein the deployment mechanism
comprises a pop-rivet mechanism.
19. The implant of claim 16, wherein the deployment mechanism
comprises a moveable member that extends into the implant.
20. The implant of claim 19, wherein the member comprises a toggle
bolt.
21. The implant of claim 19, wherein the member comprises a
pullable rod.
22. The implant of claim 19, wherein the member comprises a hollow
portion with at least one opening positioned at the outlet portion
and in fluid communication with the anterior chamber.
23. The implant of claim 22, wherein the at least one opening
comprises a side opening in fluid communication with the
physiological outflow pathway to allow flow of fluid from the
anterior chamber to the physiological outflow pathway.
24. The implant of claim 12, wherein the physiological outflow
pathway comprises Schlemm's canal.
25. The implant of claim 24, wherein the eye tissue comprises
trabecular meshwork.
26. The implant of claim 12, wherein the second anchor is
configured to move from a first configuration to a second
configuration during deployment.
Description
RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser.
No. 11/860,785, filed Sep. 25, 2007, now U.S. Pat. No. 8,337,445
B2, issued Dec. 25, 2012, which is a divisional of U.S. application
Ser. No. 11/255,625, filed Oct. 21, 2005, now U.S. Pat. No.
7,273,475 B2, issued Sep. 25, 2007, which is a continuation of U.S.
application Ser. No. 10/139,800, filed May 3, 2002, now U.S. Pat.
No. 7,094,225 B2, issued Aug. 22, 2006, which claims the benefit of
U.S. Provisional Application No. 60/288,325, filed May 3, 2001,
entitled MEDICAL DEVICE AND METHODS OF USE FOR GLAUCOMA TREATMENT,
and the entire contents of each are hereby incorporated by
reference herein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates generally medical devices and methods
for the treatment of glaucoma in an animal eye and, more
particularly, to medical devices and methods for treating tissue of
the trabecular meshwork and for Schlemm's canal of the eye to
restore or rejuvenate a portion or all of the normal physiological
function of directing aqueous outflow for maintaining a normal
intraocular pressure in the eye.
[0004] 2. Description of the Related Art
[0005] The human eye is a specialized sensory organ capable of
light reception and able to receive visual images. The trabecular,
meshwork serves as a drainage channel and is located in anterior
chamber angle formed between the iris and the cornea. The
trabecular meshwork maintains a balanced pressure in the anterior
chamber of the eye by draining aqueous humor from the anterior
chamber.
[0006] About two percent of people in the United States have
glaucoma. Glaucoma is a group of eye diseases encompassing a broad
spectrum of clinical presentations, etiologies, and treatment
modalities. Glaucoma causes pathological changes in the optic
nerve, visible on the optic disk, and it causes corresponding
visual field loss, resulting in blindness if untreated. Lowering
intraocular pressure is the major treatment goal in all
glaucomas.
[0007] In glaucomas associated with an elevation in eye pressure
(intraocular hypertension), the source of resistance to outflow is
mainly in the trabecular meshwork. The tissue of the trabecular
meshwork allows the aqueous humor ("aqueous") to enter Schlemm's
canal, which then empties into aqueous collector channels in the
posterior wall of Schlemm's canal and then into aqueous veins,
which form the episcleral venous system. Aqueous humor is a
transparent liquid that fills the region between the cornea, at the
front of the eye, and the lens. The aqueous humor is continuously
secreted by the ciliary body around the lens, so there is a
constant flow of aqueous humor from the ciliary body to the eye's
front chamber. The eye's pressure is determined by a balance
between the production of aqueous and its exit through the
trabecular meshwork (major route) or uveal scleral outflow (minor
route). The trabecular meshwork is located between the outer rim of
the iris and the back of the cornea, in the anterior chamber angle.
The portion of the trabecular meshwork adjacent to Schlemm's canal
(the juxtacanalicular meshwork) causes most of the resistance to
aqueous outflow.
[0008] Glaucoma is grossly classified into two categories:
closed-angle glaucoma, also known as angle closure glaucoma, and
open-angle glaucoma. Closed-angle glaucoma is caused by closure of
the anterior chamber angle by contact between the iris and the
inner surface of the trabecular meshwork. Closure of this
anatomical angle prevents normal drainage of aqueous humor from the
anterior chamber of the eye.
[0009] Open-angle glaucoma is any glaucoma in which the angle of
the anterior chamber remains open, but the exit of aqueous through
the trabecular meshwork is diminished. The exact cause for
diminished filtration is unknown for most cases of open-angle
glaucoma. Primary open-angle glaucoma is the most common of the
glaucomas, and it is often asymptomatic in the early to moderately
advanced stage. Patients may suffer substantial, irreversible
vision loss prior to diagnosis and treatment. However, there are
secondary open-angle glaucomas which may include edema or swelling
of the trabecular spaces (e.g., from corticosteroid use), abnormal
pigment dispersion, or diseases such as hyperthyroidism that
produce vascular congestion.
[0010] Current therapies for glaucoma are directed at decreasing
intraocular pressure. Medical therapy includes topical ophthalmic
drops or oral medications that reduce the production or increase
the outflow of aqueous. However, these drug therapies for glaucoma
are sometimes associated with significant side effects, such as
headache, blurred vision, allergic reactions, death from
cardiopulmonary complications, and potential interactions with
other drugs.
[0011] When drug therapy fails, surgical therapy is used. Surgical
therapy for open-angle glaucoma consists of laser trabeculoplasty,
trabeculectomy, and implantation of aqueous shunts after failure of
trabeculectomy or if trabeculectomy is unlikely to succeed.
Trabeculectomy is a major surgery that is widely used and is
augmented with topically applied anticancer drugs, such as
5-flurouracil or mitomycin-C to decrease scarring and increase the
likelihood of surgical success.
[0012] Approximately 100,000 trabeculectomies are performed on
Medicare-age patients per year in the United States. This number
would likely increase if the morbidity associated with
trabeculectomy could be decreased. The current morbidity associated
with trabeculectomy consists of failure (10-15%); infection (a life
long risk of 2-5%); choroidal hemorrhage, a severe internal
hemorrhage from low intraocular pressure, resulting in visual loss
(1%); cataract formation; and hypotony maculopathy (potentially
reversible visual loss from low intraocular pressure).
[0013] For these reasons, surgeons have tried for decades to
develop a workable surgery for the trabecular meshwork.
[0014] The surgical techniques that have been tried and practiced
are goniotomy/trabeculotomy and other mechanical disruptions of the
trabecular meshwork, such as trabeculopuncture, goniophotoablation,
laser trabecular ablation, and goniocurretage. These are all major
operations and are briefly described below.
[0015] Goniotomy/Trabeculotomy: Goniotomy and trabeculotomy are
simple and directed techniques of microsurgical dissection with
mechanical disruption of the trabecular meshwork. These initially
had early favorable responses in the treatment of open-angle
glaucoma. However, long-term review of surgical results showed only
limited success in adults. In retrospect, these procedures probably
failed due to cellular repair and fibrosis mechanisms and a process
of "filling in." Filling in is a detrimental effect of collapsing
and closing in of the created opening in the trabecular meshwork.
Once the created openings close, the pressure builds back up and
the surgery fails.
[0016] Trabeculopuncture: Q-switched Neodymium (Nd) YAG lasers also
have been investigated as an optically invasive technique for
creating full-thickness holes in trabecular meshwork. However, the
relatively small hole created by this trabeculopuncture technique
exhibits a filling-in effect and fails.
[0017] Goniophotoablation/Laser Trabecular Ablation:
Goniophotoablation is disclosed by Berlin in U.S. Pat. No.
4,846,172 and involves the use of an excimer laser to treat
glaucoma by ablating the trabecular meshwork. This was demonstrated
not to succeed by clinical trial. Hill et al. used an Erbium:YAG
laser to create full-thickness holes through trabecular meshwork
(Hill et al., Lasers in Surgery and Medicine 11:341-346, 1991).
This technique was investigated in a primate model and a limited
human clinical trial at the University of California, Irvine.
Although morbidity was zero in both trials, success rates did not
warrant further human trials. Failure was again from filling in of
surgically created defects in the trabecular meshwork by repair
mechanisms. Neither of these is a viable surgical technique for the
treatment of glaucoma.
[0018] Goniocurettage: This is an ab interno (from the inside),
mechanically disruptive technique that uses an instrument similar
to a cyclodialysis spatula with a microcurette at the tip. Initial
results were similar to trabeculotomy: it failed due to repair
mechanisms and a process of filling in.
[0019] Although trabeculectomy is the most commonly performed
filtering surgery, viscocanalostomy (VC) and non-penetrating
trabeculectomy (NPT) are two new variations of filtering surgery.
These are ab externo (from the outside), major ocular procedures in
which Schlemm's canal is surgically exposed by making a large and
very deep scleral flap. In the VC procedure, Schlemm's canal is
cannulated and viscoelastic substance injected (which dilates
Schlemm's canal and the aqueous collector channels). In the NPT
procedure, the inner wall of Schlemm's canal is stripped off after
surgically exposing the canal.
[0020] Trabeculectomy, VC, and NPT involve the formation of an
opening or hole under the conjunctiva and scleral flap into the
anterior chamber, such that aqueous humor is drained onto the
surface of the eye or into the tissues located within the lateral
wall of the eye. These surgical operations are major procedures
with significant ocular morbidity. When trabeculectomy, VC, and NPT
are thought to have a low chance for success, a number of
implantable drainage devices have been used to ensure that the
desired filtration and outflow of aqueous humor through the
surgical opening will continue. The risk of placing a glaucoma
drainage device also includes hemorrhage, infection, and diplopia
(double vision).
[0021] Examples of implantable shunts and surgical methods for
maintaining an opening for the release of aqueous humor from the
anterior chamber of the eye to the sclera or space beneath the
conjunctiva have been disclosed in, for example, U.S. Pat. No.
6,059,772 to Hsia et al., and U.S. Pat. No. 6,050,970 to
Baerveldt.
[0022] All of the above surgeries and variations thereof have
numerous disadvantages and moderate success rates. They involve
substantial trauma to the eye and require great surgical skill in
creating a hole through the full thickness of the sclera into the
subconjunctival space. The procedures are generally performed in an
operating room and have a prolonged recovery time for vision.
[0023] The complications of existing filtration surgery have
prompted ophthalmic surgeons to find other approaches to lowering
intraocular pressure or treating tissue of trabecular meshwork.
[0024] The trabecular meshwork and juxtacanalicular tissue together
provide the majority of resistance to the outflow of aqueous and,
as such, are logical targets for tissue stimulation and/or
rejuvenating in the treatment of open-angle glaucoma. In addition,
minimal amounts of tissue are displaced and functions of the
existing physiologic outflow pathways are restored.
[0025] As reported in Arch. Ophthalm. (2000) 118:412, glaucoma
remains a leading cause of blindness, and filtration surgery
remains an effective, important option in controlling the disease.
However, modifying existing filtering surgery techniques in any
profound way to increase their effectiveness appears to have
reached a dead end. The article further states that the time has
come to search for new surgical approaches that may provide better
and safer care for patients with glaucoma.
[0026] Therefore, there is a great clinical need for a method of
treating glaucoma that is faster, safer, and less expensive than
currently available drug or surgical modalities.
SUMMARY OF THE INVENTION
[0027] The trabecular meshwork and juxtacanalicular tissue together
provide the majority of resistance to the outflow of aqueous and,
as such, are logical targets for tissue stimulation and/or
rejuvenating in the treatment of glaucoma. Various embodiments of
glaucoma devices and methods are disclosed herein for rejuvenating
the physiological functions of the trabecular meshwork by
therapeutically reversing the aqueous flow through the trabecular
meshwork, or applying vibrational energy to tissue of trabecular
meshwork effective to reduce intraocular pressure (IOP).
[0028] Copending U.S. application Ser. No. 09/704,276, filed Nov.
1, 2000, entitled GLAUCOMA TREATMENT DEVICE, disclose devices and
methods of placing a trabecular shunt ab interno, i.e., from inside
the anterior chamber through the trabecular meshwork, into
Schlemm's canal. The entire contents of this copending patent
application are hereby incorporated by reference herein. The
invention encompasses both ab interno and ab externo glaucoma
shunts and methods thereof.
[0029] One technique performed in accordance with aspects herein
may be referred to generally as "trabecular bypass surgery."
Advantages of this type of surgery include lowering intraocular
pressure in a manner which is simple, effective, disease
site-specific, and can potentially be performed on an outpatient
basis.
[0030] Generally, trabecular bypass surgery (TBS) creates an
opening, a slit, or a hole through trabecular meshwork with minor
microsurgery. TBS has the advantage of a much lower risk of
choroidal hemorrhage and infection than prior techniques, and it
uses existing physiologic outflow mechanisms. In some aspects, this
surgery can potentially be performed under topical or local
anesthesia on an outpatient basis with rapid visual recovery. To
prevent "filling in" of the hole, a biocompatible elongated device
is placed within the hole and serves as a stent. U.S. patent
application Ser. No. 09/549,350, filed Apr. 14, 2000, entitled
APPARATUS AND METHOD FOR TREATING GLAUCOMA, the entire contents of
which are hereby incorporated by reference herein, discloses
trabecular bypass surgery.
[0031] Some aspects of the invention relate to a medical device
system for treating tissue of trabecular meshwork of an eye
comprising aspiration means for inducing a liquid flow through the
trabecular meshwork in an opposite direction of a physiological
aqueous outflow pathway. In one embodiment, the aspiration means
comprises an elongated tubular member having a proximal end, a
distal end and an inflatable cup balloon mounted at the distal end,
wherein the cup balloon has a balloon rim defining an isolated
enclosure adapted for inducing the liquid flow through the
trabecular meshwork by a suction power exerted at the proximal
end.
[0032] Some aspects of the invention relate to a method for
treating tissue of trabecular meshwork of an eye comprising
directing a liquid flow through the trabecular meshwork in an
opposite direction of a physiological aqueous outflow pathway. In
one embodiment, the aspiration means are provided for directing a
liquid flow through the trabecular meshwork in an opposite
direction of the physiological aqueous outflow pathway.
[0033] Some aspects of the invention relate to a medical device for
treating tissue of trabecular meshwork of an eye comprising an
ultrasound arrangement on the medical device for providing
ultrasonic vibrational energy to stimulate the tissue of the
trabecular meshwork. In one embodiment, the device is positioned
inside Schlemm's canal in an ab externo procedure. In another
embodiment, the device is positioned through the trabecular
meshwork in an ab interno procedure.
[0034] Some aspects of the invention relate to a medical device for
treating tissue of trabecular meshwork of an eye comprising a fiber
optic arrangement on the medical device for providing light imaging
function for tissue characterization. In one embodiment, the light
imaging function comprises a near infrared Raman spectroscopy.
[0035] In accordance with some embodiments, medical devices and
methods are provided for treating tissue of the trabecular meshwork
and /or Schlemm's canal of an eye to restore or rejuvenate a
portion or all of the normal physiological function of directing
aqueous outflow for maintaining a normal intraocular pressure in
the eye.
[0036] For purposes of summarizing the invention, certain aspects,
advantages and novel features of the invention have been described
herein above. Of course, it is to be understood that not
necessarily all such advantages may be achieved in accordance with
any particular embodiment of the invention. Thus, the invention may
be embodied or carried out in a manner that achieves or optimizes
one advantage or group of advantages as taught or suggested herein
without necessarily achieving other advantages as may be taught or
suggested herein.
[0037] All of these embodiments are intended to be within the scope
of the invention herein disclosed. These and other embodiments of
the invention will become readily apparent to those skilled in the
art from the following detailed description of the preferred
embodiments having reference to the attached figures, the invention
not being limited to any particular preferred embodiment(s)
disclosed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0038] Having thus summarized the general nature of the invention
and some of its features and advantages, certain preferred
embodiments and modifications thereof will become apparent to those
skilled in the art from the detailed description herein having
reference to the figures that follow, of which:
[0039] FIG. 1 is a coronal or sagittal cross-sectional view of an
eye;
[0040] FIG. 2 is an enlarged cross-sectional view of an anterior
chamber angle of the eye of FIG. 1;
[0041] FIG. 3 is a simplified partial view of an eye schematically
illustrating the outflow pathway of aqueous through trabecular
meshwork under normal physiological conditions;
[0042] FIG. 4 is a simplified partial view of an eye schematically
illustrating the placement and use of a system therein for
reversing trabecular outflow to rejuvenate dysfunctional trabecular
meshwork utilizing an ab interno procedure and having features and
advantages in accordance with one embodiment of the invention;
[0043] FIG. 5 is a simplified enlarged view of an aspiration means
of the system of FIG. 4 for enhancing the flow reversal through the
trabecular meshwork;
[0044] FIG. 6 is a simplified partial view of an eye schematically
illustrating the placement and use of a system therein for
reversing trabecular outflow to stimulate and/or rejuvenate
dysfunctional trabecular meshwork utilizing an ab externo catheter
method and having features and advantages in accordance with one
embodiment of the invention;
[0045] FIG. 7 is a simplified partial view of an eye schematically
illustrating the placement and use of a system therein for
reversing trabecular outflow to stimulate and/or rejuvenate
dysfunctional trabecular meshwork utilizing an ab externo jet
stream method and having features and advantages in accordance with
one embodiment of the invention;
[0046] FIG. 8 is a simplified partial view of an eye schematically
illustrating the placement and use of a system therein for
rejuvenating dysfunctional trabecular meshwork by an ab externo
vibrational energy method and having features and advantages in
accordance with one embodiment of the invention;
[0047] FIG. 9 is a simplified partial view of an eye schematically
illustrating the placement and use of a system therein for
rejuvenating dysfunctional trabecular meshwork by an ab interno
vibrational energy method and having features and advantages in
accordance with one embodiment of the invention;
[0048] FIG. 10 is a simplified partial view of an eye schematically
illustrating the placement and use of a system therein for
rejuvenating dysfunctional trabecular meshwork by an ab externo
optical energy method and having features and advantages in
accordance with one embodiment of the invention;
[0049] FIG. 11 is a simplified partial view of an eye illustrating
the implantation of a medical device using an ab externo procedure
having features and advantages in accordance with one embodiment of
the invention;
[0050] FIG. 12 is a simplified partial view of an eye schematically
illustrating the placement and use of a system therein for
reversing trabecular outflow to rejuvenate dysfunctional trabecular
meshwork utilizing an ab interno procedure and having features and
advantages in accordance with one embodiment of the invention;
[0051] FIG. 13 is a simplified partial view of an eye schematically
illustrating an episcleral retrograde injection to infuse a liquid
into Schlemm's canal and having features and advantages in
accordance with one embodiment of the invention;
[0052] FIG. 14 is a simplified cross-sectional view of an eye
illustrating the placement and use of a treatment ring therein and
having features and advantages in accordance with one embodiment of
the invention;
[0053] FIG. 15 is a schematic view of an instrument for deploying
the treatment ring of FIG. 14 within an eye and having features and
advantages in accordance with one embodiment of the invention;
[0054] FIG. 16 is a simplified partial view of an eye schematically
illustrating the use and placement of a multi-part stent therein
and having features and advantages in accordance with one
embodiment of the invention;
[0055] FIGS. 17A and 17B are simplified partial views of an eye
schematically illustrating the use and placement of a toggle bolt
shunt therein and having features and advantages in accordance with
one embodiment of the invention, wherein FIG. 17A shows the shunt
in a non-deployed or contracted state or shape and FIG. 17B shows
the shunt in a deployed or expanded state or shape;
[0056] FIG. 18 a simplified partial view of an eye schematically
illustrating the use and placement of a thermal catheter device
therein and having features and advantages in accordance with one
embodiment of the invention; and
[0057] FIG. 19 a simplified partial view of an eye schematically
illustrating the use and placement of a vision catheter device
therein and having features and advantages in accordance with one
embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0058] The preferred embodiments of the invention described herein
relate particularly to surgical and therapeutic treatment of
glaucoma through reduction of intraocular pressure and stimulation
and/or rejuvenation of the trabecular meshwork tissue. While the
description sets forth various embodiment specific details, it will
be appreciated that the description is illustrative only and should
not be construed in any way as limiting the invention. Furthermore,
various applications of the invention, and modifications thereto,
which may occur to those who are skilled in the art, are also
encompassed by the general concepts described herein.
[0059] FIG. 1 is a cross-sectional view of an eye 10, while FIG. 2
is a close-up view showing the relative anatomical locations of a
trabecular meshwork 21, an anterior chamber 20, and Schlemm's canal
22. A sclera 11 is a thick collagenous tissue which covers the
entire eye 10 except a portion which is covered by a cornea 12.
[0060] Referring to FIGS. 1 and 2, the cornea 12 is a thin
transparent tissue that focuses and transmits light into the eye
and through a pupil 14, which is a circular hole in the center of
an iris 13 (colored portion of the eye). The cornea 12 merges into
the sclera 11 at a juncture referred to as a limbus 15. A ciliary
body 16 extends along the interior of the sclera 11 and is
coextensive with a choroid 17. The choroid 17 is a vascular layer
of the eye 10, located between the sclera 11 and a retina 18. An
optic nerve 19 transmits visual information to the brain and is the
anatomic structure that is progressively destroyed by glaucoma.
[0061] Still referring to FIGS. 1 and 2, the anterior chamber 20 of
the eye 10, which is bound anteriorly by the cornea 12 and
posteriorly by the iris 13 and a lens 26, is filled with aqueous
humor (also referred to as "aqueous" herein). Aqueous is produced
primarily by the ciliary body 16, then moves anteriorly through the
pupil 14 and reaches an anterior chamber angle 25, formed between
the iris 13 and the cornea 12.
[0062] As best illustrated by the drawing of FIG. 2, in a normal
eye, aqueous is removed from the anterior chamber 20 through the
trabecular meshwork 21. Aqueous passes through the trabecular
meshwork 21 into Schlemm's canal 22 and thereafter through a
plurality of aqueous veins 23, which merge with blood-carrying
veins, and into systemic venous circulation. Intraocular pressure
is maintained by an intricate balance between secretion and outflow
of aqueous in the manner described above. Glaucoma is, in most
cases, characterized by an excessive buildup of aqueous in the
anterior chamber 20 which leads to an increase in intraocular
pressure. Fluids are relatively incompressible, and thus
intraocular pressure is distributed relatively uniformly throughout
the eye 10.
[0063] As shown in FIG. 2, the trabecular meshwork 21 is adjacent a
small portion of the sclera 11. Exterior to the sclera 11 is a
conjunctiva 24. Traditional procedures that create a hole or
opening for implanting a device through the tissues of the
conjunctiva 24 and sclera 11 involve extensive surgery, as compared
to surgery for implanting a device, as described herein, which
ultimately resides entirely within the confines of the sclera 11
and cornea 12.
[0064] FIG. 3 is a simplified partial view of an eye 10
schematically illustrating the outflow pathway of aqueous under
normal physiological conditions. The direction of flow is generally
indicated by arrows 30. As discussed above, in a normal eye,
aqueous is removed from the anterior chamber 20 through the
trabecular meshwork 21. Aqueous then passes through the trabecular
meshwork 21 into Schlemm's canal 22 and thereafter eventually into
systemic venous circulation. The flow of aqueous or other liquids
through the trabecular meshwork 21 is sometimes referred to as
"trabecular outflow" herein.
[0065] Reversed Trabecular Outflow
[0066] The embodiments of FIGS. 4-7 illustrate aspects and features
of flushing or treating the trabecular meshwork by providing a flow
through all or part of the trabecular meshwork in the opposite
direction to that normally experienced by the trabecular meshwork
during normal physiological function. That is, in a direction
generally opposite to or against a normal outflow such as the
outflow pathway under normal physiological conditions illustrated
in FIG. 3.
[0067] Some purposes for this treatment are (i) to administer
medication or other therapeutic agents to the meshwork or lining of
Schlemm's canal; (ii) to flush out debris that may be occluding the
meshwork or Schlemm's canal; (iii) to open channels through the
meshwork and endothelial layer to improve outflow; or (iv) to
stimulate or rejuvenate the tissue of trabecular meshwork for
restoring its normal physiological function. Advantageously, and as
discussed further below, trabecular meshwork flushing flow allows
an ab interno or ab externo procedure for stimulating and/or
treating the dysfunctional trabecular meshwork.
[0068] Certain embodiments of such medication or other therapeutic
agents for treating trabecular meshwork or lining of Schlemm's
canal are disclosed in copending U.S. application Ser. No.
10/046,137, filed Nov. 8, 2001, entitled DRUG-RELEASE TRABECULAR
IMPLANT FOR GLAUCOMA TREATMENT, the entire contents of which are
hereby incorporated by reference herein. As discussed in further
detail later herein, in accordance with some embodiments, a
therapeutic liquid is introduced through an inlet port of a medical
device system (described below) for providing a liquid back flow or
reversed outflow through the trabecular meshwork in an opposite
direction to that of the physiological aqueous outflow pathway.
[0069] The therapeutic liquid may comprise a pharmaceutical
substance selected from a group consisting of Imidazole
antiproliferative agents, quinoxalines, phosphonylmethoxyalkyl
nucleotide analogs and related nucleotide analogs, potassium
channel blockers, synthetic oligonucleotides, Transforming Growth
Factor-beta (TGF-beta), 5-[1-hydroxy-2- [2-(2-methoxyphenoxypethyl
amino]ethyl]-2-methylbenzenesulfonamide, guanylate cyclase
inhibitors, methylene blue, butylated hydroxyanisole, and
N-methylhydroxylamine, 2-(4-methylaminobutoxy) diphenylmethane, a
combination of apraclonidine and timolol, cloprostenol analogs or
fluprostenol analogs, an ophthalmic composition that provides a
sustained release of a water soluble medicament, said water soluble
medicament comprising a crosslinked carboxy-containing polymer, a
sugar, and water, a non-corneotoxic serine-threonine kinase
inhibitor, a composition of non-steroidal glucocorticoid
antagonist, and a prostaglandin analog or a derivative thereof.
[0070] Ab Interno Global Trabecular Meshwork Flush/Treatment
[0071] FIG. 4 is a simplified partial view of an eye 10 generally
illustrating the placement and use of a medical device system 40
therein for reversing trabecular outflow and having features and
advantages in accordance with one embodiment. The system 40
generally comprises a trabecular device 42 for establishing an
outflow pathway and a reversed trabecular flushing flow (that is,
in a direction generally opposite to or against a normal outflow
such as the outflow pathway under normal physiological conditions
illustrated in FIG. 3). In one embodiment, the system 40 further
comprises aspiration means 44 for treating tissue of the trabecular
meshwork 21 of the eye 10 by inducing a liquid flow through the
trabecular meshwork 21 in an opposite direction to that of a
physiological aqueous outflow pathway.
[0072] Referring to FIG. 4, the system 40 reverses the outflow to
stimulate or rejuvenate the dysfunctional trabecular meshwork. The
term "rejuvenate" is herein generally intended to mean to restore a
part or all of the normal physiological function. Stated
differently, the use of the term "rejuvenate" denotes at least some
or full restoration of the normal physiological function.
[0073] In the illustrated embodiment of FIG. 4, the trabecular
device 42 generally comprises an elongate body having a proximal
section 46 with a proximal end 48, a distal section 50 and a distal
end 52, and a lumen 54 extending therethrough and terminating in
one or more outlet ports 56. Aqueous or other liquid flows into the
lumen 54 at the proximal end 48 and exits through the one or more
outlet ports 56.
[0074] As shown in the embodiment of FIG. 4, the trabecular device
42 is inserted through the trabecular meshwork 21 so that the
distal section 50 is positioned inside Schlemm's canal 22 utilizing
an ab interno procedure. To facilitate the trabecular flow through
the trabecular device 42, a liquid inlet port 58 of the device 40
is generally placed outside the eye 10 for introducing a
pressurized therapeutic liquid flow while the one or more liquid
outlet ports 56 of the trabecular device 42 are generally
positioned within Schlemm's canal 22.
[0075] Referring to FIG. 4, the flushing flow originates from the
anterior chamber 20 or from an external irrigation applicator (as
generally indicated by arrow 60A), enters the trabecular device 42
(as generally indicated by arrow 60B), enters Schlemm's canal 22
through the one or more outlet ports 56 (as generally indicated by
arrows 60C), reversibly passes through the trabecular meshwork 21
(as generally indicated by arrows 60D) into the anterior chamber 20
or into the aspiration means 44 within the anterior chamber 20 (as
generally indicated by arrows 60E). The reverse flushing outflow or
backflow is created by a pressure difference, differential or
gradient created between a higher pressure in Schlemm's canal and a
lower pressure in the anterior chamber 20 or in the aspiration
means 44.
[0076] As indicated above, in accordance with one embodiment, to
facilitate and enhance the flushing back flow (or reversed outflow)
to travel effectively through the trabecular meshwork 21,
aspiration means 44 are provided at the surface 62 of the
trabecular meshwork 21 exposed to the anterior chamber 20. The
aspiration means 44 induce a liquid flow through the trabecular
meshwork in an opposite direction to that of a physiological
aqueous outflow pathway.
[0077] Referring to FIGS. 4 and 5, in accordance with one
embodiment, the aspiration means 44 comprises one or more suction
devices 70 which are placed on the top surface 62 of the trabecular
meshwork 21. The suction device 70 generally comprises an elongated
tubular member, introducer or irrigating applicator 72 and an
inflatable cup or cone balloon 74.
[0078] Still referring to FIGS. 4 and 5, the tubular member 72 has
a proximal end 76, a distal end 78 and a lumen 80 extending
therethrough. The inflatable cup balloon 74 is mounted at the
distal end 78. The cup balloon 74 has a balloon rim 82 defining an
isolated enclosure 84 for aspiration of fluid through the lumen 80
of the introducer 72. The enclosure 84 is adapted for inducing
liquid flow through the trabecular meshwork 21 and into the lumen
80 by suction power (e.g., by creating a partial vacuum or reduced
pressure relative to the appropriate ambient pressure) exerted at
the proximal end 76. The device 70 is preferably used in an ab
interno procedure.
[0079] The inflatable balloon 72 (FIGS. 4 and 5) and its principles
for forming an isolated enclosure 84 by an inflating fluid are well
known to one of ordinary skill in the art. During the entry and
exit phases of the device 70 into and out of the eye 10, the
balloon 72 is preferably in a collapsed or compact state to have a
low profile adapted for easy insertion and withdrawal.
[0080] The embodiment as shown in FIG. 4 enables a completely ab
interno procedure that advantageously acts on or treats the
majority and substantially all of the trabecular meshwork 21. As
discussed above, it is one embodiment of flushing or treating the
trabecular meshwork 21 by providing a flow through all or part of
the trabecular meshwork 21 in the opposite direction to that
normally experienced by trabecular meshwork 21 during normal
physiological function. The trabecular device 42 and the aspiration
means 44 of the system 40 are both inserted in an ab interno
procedure.
[0081] This procedure of the embodiments of FIGS. 4 and 5 may
optionally be combined with an episcleral ring that is pressed onto
the eye to occlude the venous system downstream of the collector
channels. Advantageously, this further assists in achieving the
pressures that are sufficiently high to provide effective back flow
through the trabecular meshwork 21 by creating a desirable pressure
difference, differential or gradient which drives the reversed
outflow.
[0082] It is one object to provide a method for treating tissue of
trabecular meshwork of an eye comprising directing a liquid flow
through the trabecular meshwork in an opposite direction to that of
a physiological aqueous outflow pathway. The method further
comprises aspiration means for directing a liquid flow through the
trabecular meshwork in an opposite direction of the physiological
aqueous outflow pathway, wherein the aspiration means may comprise
an elongated tubular member having a proximal end, a distal end and
an inflatable cup balloon mounted at the distal end, wherein the
cup balloon has a balloon rim defining an isolated enclosure
adapted for inducing the liquid flow through the trabecular
meshwork by a suction power exerted at the proximal end.
[0083] Ab Externo Trabecular Meshwork Flush/Treatment
[0084] Lynch and Brown in PCT Publication No. WO 00/64389,
published Nov. 2, 2000, entitled TRABECULOTOMY DEVICE AND METHOD
FOR TREATING GLAUCOMA, PCT Publication No. WO 00/64390, published
Nov. 2, 2000, entitled INFLATABLE DEVICE AND METHOD FOR TREATING
GLAUCOMA, PCT Publication No. WO 00/64391, published Nov. 2, 2000,
entitled STENT DEVICE AND METHOD FOR TREATING GLAUCOMA, and PCT
Publication No. WO 00/64393, published Nov. 2, 2000, entitled SHUNT
DEVICE AND METHOD FOR TREATING GLAUCOMA, the entire contents of
each one of which are hereby incorporated by reference herein,
disclose devices and methods for entering Schlemm's canal in an ab
externo manner for treating glaucoma.
[0085] FIG. 6 is a simplified partial view of an eye 10 generally
illustrating the placement and use of a medical device system 90
therein for reversing trabecular outflow and having features and
advantages in accordance with one embodiment. The system 90
generally comprises a catheter-type device 92 for establishing a
reversed trabecular flushing flow (that is, in a direction
generally opposite to or against a normal outflow such as the
outflow pathway under normal physiological conditions illustrated
in FIG. 3). In one embodiment, the system 90 further comprises
aspiration means 44 for treating tissue of the trabecular meshwork
21 of the eye 10 by inducing a liquid flow through the trabecular
meshwork 21 in an opposite direction to that of a physiological
aqueous outflow pathway.
[0086] Referring to FIG. 6, the inflow catheter 92 can be inserted
into Schlemm's canal 22 either via an external incision that
unroofs the Schlemm's canal 22 or through an episcleral vein (or
other blood vessel downstream in the circulatory system) to a
collector channel then into Schlemm's canal 22. The outflow portion
of the instrument, that is, the aspiration means 44, is placed in
the anterior chamber 20 to take up the fluid volume that passes
through the trabecular meshwork 21.
[0087] In the illustrated embodiment of FIG. 6, the catheter device
92 generally comprises a distal section 94, a distal end 96 and a
plurality of micropores 98 on the distal section for liquid flow.
Preferably, the aspiration means 44 comprises one or more
inflatable balloon type suction devices 70 (discussed above in
reference to FIG. 5) which are placed on the top surface 62 of the
trabecular meshwork 21.
[0088] Referring to the embodiment of FIG. 6, the catheter device
92 is inserted from a puncture at the scleral wall of the eye 10 by
an ab externo procedure so that the distal section 94 is positioned
in Schlemm's canal 22. By maintaining a pressure difference between
Schlemm's canal 22 and the anterior chamber 20, a reversed
trabecular flow or back flow (as generally indicated by arrows
100A, 100B, and 100C) is created from Schlemm's canal 22 through
the trabecular meshwork 21 and into the anterior chamber 20 or the
aspiration means 44. The reverse flushing outflow or backflow is
created by a pressure difference, differential or gradient created
between a higher pressure in Schlemm's canal 22 and a lower
pressure in the anterior chamber 20 or in the aspiration means
44.
[0089] As indicated above, in accordance with one embodiment, to
facilitate and enhance the flushing back flow (or reversed outflow)
to travel effectively through the trabecular meshwork 21,
aspiration means 44 (FIG. 6) are provided at the surface 62 of the
trabecular meshwork 21 exposed to the anterior chamber 20. The
aspiration means 44 induce a liquid flow through the trabecular
meshwork 21 in an opposite direction to that of a physiological
aqueous outflow pathway.
[0090] The embodiment shown in FIG. 6 enables a combined ab externo
catheter procedure with an ab interno aspiration means that act on
or treat all or part of the trabecular meshwork 21. Since the
pressure in Schlemm's canal 22 is kept at a relatively high value,
it is also used to stimulate the dysfunctional tissue inside
Schlemm's canal 22, the collector channels or the trabecular
meshwork 21. This method is well suited to cases wherein the
Schlemm's canal 22 has shrunk as in trabeculectomy patients.
[0091] This procedure of the embodiment of FIG. 6 may optionally be
combined with an episcleral ring that is pressed onto the eye to
occlude the venous system downstream of the collector channels.
Advantageously, this further assists in achieving the pressures
that are sufficiently high to provide effective back flow through
the trabecular meshwork 21 by creating a desirable pressure
difference, differential or gradient which drives the reversed
outflow.
[0092] FIG. 7 is a simplified partial view of an eye 10 generally
illustrating the placement and use of a medical device system 110
therein for reversing trabecular outflow and having features and
advantages in accordance with one embodiment. The system 110
generally comprises a catheter-type device 112 for establishing a
reversed trabecular flushing flow (that is, in a direction
generally opposite to or against a normal outflow such as the
outflow pathway under normal physiological conditions illustrated
in FIG. 3). In one embodiment, the system 110 further comprises
aspiration means 44 for treating tissue of the trabecular meshwork
21 of the eye 10 by inducing a liquid flow through the trabecular
meshwork 21 in an opposite direction to that of a physiological
aqueous outflow pathway.
[0093] Referring to FIG. 7, the inflow catheter 112 can be inserted
into Schlemm's canal 22 either via an external incision that
unroofs the Schlemm's canal 22 or through an episcleral vein (or
other blood vessel downstream in the circulatory system) to a
collector channel then into Schlemm's canal 22. The outflow portion
of the instrument, that is, the aspiration means 44, is placed in
the anterior chamber 20 to take up the fluid volume that passes
through the trabecular meshwork 21.
[0094] In the illustrated embodiment of FIG. 7, the catheter device
112 generally comprises a distal section 114, a distal end 116 with
a distal opening 118 and a throttle or narrowed neck 120 at about
or slightly downstream of the distal opening 118 for creating a
liquid jet effective for therapeutic purposes. The configuration of
the throttle or nozzle 120 can be used to control the
characteristics of the liquid jet emanating from the distal opening
118. Preferably, the aspiration means 44 comprises one or more
inflatable balloon type suction devices 70 (discussed above in
reference to FIG. 5) which are placed on the top surface 62 of the
trabecular meshwork 21.
[0095] Referring to the embodiment of FIG. 7, the catheter device
112 is inserted from a puncture at the scleral wall of the eye 10
by an ab externo procedure so that the water-jet catheter tip 114
is positioned in Schlemm's canal 22. By maintaining a pressure
difference between Schlemm's canal 22 and the anterior chamber 20,
a reversed trabecular flow or back flow (as generally indicated by
arrows 122A, 122B) is created from Schlemm's canal 22 through the
trabecular meshwork 21 and into the anterior chamber 20 or the
aspiration means 44. The reverse flushing outflow or backflow is
created by a pressure difference, differential or gradient created
between a higher pressure in Schlemm's canal 22 and a lower
pressure in the anterior chamber 20 or in the aspiration means
44.
[0096] The embodiment of FIG. 7 may also comprise injecting a
therapeutic agent, such as steroids, growth factors, angiogenic
inhibitors and the like through the catheter device 112 for
enhancing tissue rejuvenation or stimulation. These agents, water
or other liquids may be provided in the form of a cooled and/or
heated flow, as needed or desired, to further enhance tissue
rejuvenation or stimulation. The jetted flow may also be used to
scour the inner wall of Schlemm's canal 22 and adjacent trabecular
meshwork 21.
[0097] As indicated above, in accordance with one embodiment, to
facilitate and enhance the flushing back flow (or reversed outflow)
to travel effectively through the trabecular meshwork 21,
aspiration means 44 (FIG. 7) are provided at the surface 62 of the
trabecular meshwork 21 exposed to the anterior chamber 20. The
aspiration means 44 induce a liquid flow through the trabecular
meshwork 21 in an opposite direction to that of a physiological
aqueous outflow pathway.
[0098] The embodiment shown in FIG. 7 enables a combined ab externo
catheter procedure with an ab interno aspiration means that act on
or treat all or part of the trabecular meshwork 21. Since the
pressure in Schlemm's canal 22 is kept at a relatively high value,
it is also used to stimulate the dysfunctional tissue inside
Schlemm's canal 22, the collector channels or the trabecular
meshwork 21. This method is well suited to cases wherein the
Schlemm's canal 22 has shrunk as in trabeculectomy patients.
[0099] This procedure of the embodiment of FIG. 7 may optionally be
combined with an episcleral ring that is pressed onto the eye to
occlude the venous system downstream of the collector channels.
Advantageously, this further assists in achieving the pressures
that are sufficiently high to provide effective back flow through
the trabecular meshwork 21 by creating a desirable pressure
difference, differential or gradient which drives the reversed
outflow.
[0100] Schlemm's Canal and/or Trabecular Meshwork Treatment
[0101] FIG. 8 is a simplified partial view of an eye 10 generally
illustrating the placement and use of a system or device 130
therein for rejuvenating dysfunctional trabecular meshwork by an ab
externo vibrational energy method and having features and
advantages in accordance with one embodiment. The ultrasound
catheter device 130 is inserted into Schlemm's canal 22 by an ab
externo procedure.
[0102] In the illustrated embodiment of FIG. 8, the ultrasound
catheter device 130 generally comprises a catheter tip or distal
section 132, a distal end 134 and one or more ultrasound
transducers 136 on the distal section 132. As shown in FIG. 8, the
ultrasound catheter tip section 132 is inserted into Schlemm's
canal 22.
[0103] Referring to FIG. 8, the ultrasound transducer 136 is used
to heat or cause vibrations to the inner wall of Schlemm's canal 22
and the adjacent trabecular meshwork 21. The effected stimulation
of these tissues provides generally improved flow into Schlemm's
canal by reducing the resistance to outflow and/or due to more
effective fluid transmission after tissue rejuvenation. An
additional set of imaging transducers 138 may be mounted at about
the tip section 132 of the catheter device 130 proximate to the
distal end 134 for catheter deployment and positioning
purposes.
[0104] FIG. 9 is a simplified partial view of an eye 10 generally
illustrating the placement and use of a system or ultrasound device
140 therein for rejuvenating dysfunctional trabecular meshwork by
an ab interno vibrational energy method and having features and
advantages in accordance with one embodiment. The ultrasound device
140 generally comprises a tip or distal section 142, a distal end
144, a therapeutic ultrasound arrangement 146 and an imaging
ultrasound arrangement 148.
[0105] In the illustrated embodiment, the device 140 (FIG. 9) is
inserted from an incision at the cornea wall of the eye 10 and
advanced through the anterior chamber 20 to the trabecular meshwork
21. An optional self-trephine cutting tip 150 creates an opening
through the trabecular meshwork 21.
[0106] Referring to FIG. 9, the therapeutic ultrasound arrangement
146 generally comprises one or more ultrasound transducers 152. The
ultrasound arrangement 146 is positioned at an appropriate location
about the trabecular meshwork 21 and is used to heat or cause
vibrations to the tissue of the adjacent trabecular meshwork 21 for
tissue stimulation and/or rejuvenating.
[0107] Still referring to FIG. 9, the imaging ultrasound
arrangement 148 generally comprises one or more imaging transducers
154. The imaging arrangement is located at about the tip section
142 of the device 140 proximate to the distal end 144 for guiding
the deployment and positioning.
[0108] Of course, as the skilled artisan will appreciate, that the
ultrasound arrangement 146 (FIG. 9) may rest at any suitable
position within trabecular meshwork 21, as needed or desired. Also,
the therapeutic ultrasound arrangement 146 may extend into
Schlemm's canal 22, as needed or desired. The length, size, and
space of the ultrasound transducers 152 of the arrangement 146 may
be efficaciously adjusted to achieve the desired stimulating and/or
rejuvenating effects.
[0109] Newman et al. in U.S. Pat. No. 6,372,498, the entire
contents of which are hereby incorporated by reference herein,
discloses an ultrasound system that applies vibrational energy at a
specific range of frequency and intensity to enhance nucleic acid
transfection of vascular smooth muscle cells.
[0110] Tissues possess three important properties that are of
fundamental importance in ultrasound imaging. These are
attenuation, reflectivity, and speed of sound. Some ultrasound
energy that is absorbed by tissue is converted to heat adapted for
therapeutically treating a dysfunctional trabecular meshwork. In
another aspect, ultrasound creates a micro-vibration at about
50,000 cycle/sec which is therapeutically beneficial to rejuvenate
the trabecular tissue 21.
[0111] The ultrasound transducers 136 in FIG. 8 and ultrasound
transducers 152 in FIG. 9 serve to image, stimulate and/or
rejuvenate the dysfunctional trabecular tissue depending on the
ultrasound frequencies used. In accordance with one embodiment, the
suitable frequencies for this application are typically in the
range of from about 100 kiloHertz (kHz) to about 100 MegaHertz
(MHz).
[0112] As indicated above, in some embodiments, a suitable cutting
edge 150 (FIG. 9) is provided on a selected portion of the tip
section 142 with efficacy, as needed or desired, giving due
consideration to the goals of providing suitable cutting means on
the device 140 for effectively cutting through the trabecular
meshwork 21 and/or of achieving one or more of the benefits and
advantages as taught or suggested herein.
[0113] FIG. 10 is a simplified partial view of an eye 10 generally
illustrating the placement and use of a system or fiber optic
device 160 therein for rejuvenating dysfunctional trabecular
meshwork by an ab externo optical energy method and having features
and advantages in accordance with one embodiment. The fiber optic
device 160 comprises a tip 162 that is capable of emitting optic
signals and receiving the signals. As shown in FIG. 10, the tip 162
is positioned within Schlemm's canal 22.
[0114] Referring to FIG. 10, the fiber optic device 160 is deployed
to inspect Schlemm's canal 22, collector duct openings, and the
adjacent trabecular meshwork 21. The device 160 is useful to
inspect the target areas before, during or after a glaucoma
treatment of ab interno or ab externo procedures. The optic fiber
160 may also be combined with other catheter embodiments to
accomplish multi-function goals. Further, the device 160 can also
carry light enabling heating the tip 162 for thermal treatment of
Schlemm's canal 22 or the adjacent trabecular meshwork 21 for
tissue stimulation/rejuvenating.
[0115] More particularly, the fiber optic device 160 (FIG. 10) is
capable of analyzing the tissue composition using near infrared
Raman spectrum. Wise et al. in U.S. Pat. No. 6,373,567, the entire
contents of which are hereby incorporated by reference herein,
disclose a dispersive near infrared (IR) Raman spectrometer and a
means for tissue chemical identification based on the principles of
the intensity of the spectral peak height shift that correlates to
chemical concentration.
[0116] The optic fiber arrangement as illustrated in FIG. 10 can be
used to apply optical coherence tomography (OCT) principles for
diagnosing the dysfunctional or diseased Schlemm's canal 22 and/or
adjacent trabecular meshwork 21. OCT is a high-resolution imaging
modality that can provide in vivo cross-sectional images of tissue
structure with a spatial resolution of about 10 to 20 microns
(.mu.m). Radhakrishnan et al. reported real-time optical coherence
tomography of the anterior segment at 1310 nm (Arch Ophthalmol.
2001;119:1179-1185) from outside of the eye.
[0117] Advantageously, the fiber optic arrangement 160 of FIG. 10
enables a high-speed in vivo diagnosis about the dynamic
physiological functions of aqueous outflow at about the trabecular
meshwork 21 and Schlemm's canal 22 for site-specific determination
of the tissue abnormality. In accordance with one embodiment, the
suitable wavelengths for this application are typically in the
wavelength range of from about 820-840 Nanometers (nm) and about
1300-1320 nm.
[0118] Other Features
[0119] The device or catheter of the embodiments disclosed herein
can be dimensioned in a wide variety of manners. Referring in
particular to devices or apparatuses inserted through a trabecular
meshwork 21 into Schlemm's canal 22 as illustrated in FIGS. 4 and
9, the depth of Schlemm's canal 22 is typically about less than 400
microns (.mu.m). Accordingly, the devices 42, 140 are dimensioned
so that the portion extending into Schlemm's canal 22 is typically
less than about 400 .mu.m. The diameters of the devices 42, 140 are
dimensioned typically in the range from about 100 .mu.m to about
300 .mu.m which is roughly the typical range of the thickness of
the trabecular meshwork 21. Also referring in particular to
catheters, devices or apparatuses, inserted into Schlemm's canal 22
as illustrated FIGS. 6-8 and 10, the diameter is dimensioned
typically in the range of from about 25 .mu.m to about 200 .mu.m
for easy insertion and deployment.
[0120] The systems, devices and apparatuses of the exemplary
embodiments may be manufactured or fabricated by a wide variety of
techniques. These include, without limitation, by molding,
extrusion, or other micro-machining techniques, among other
suitable techniques.
[0121] The trabecular device 42 (FIG. 4), introducer device 72
(FIG. 5), catheter device 92 (FIG. 6), catheter device 112 (FIG.
7), catheter device 130 (FIG. 8), trabecular device 140 (FIG. 9),
fiber optic device 160 (FIG. 10) of the exemplary embodiments
preferably comprise a biocompatible material (bio-material) such
that inflammation arising due to irritation between the outer
surface of the device and the surrounding tissue is minimized.
Biocompatible materials which may be used for these devices
preferably include, but are not limited to, titanium, titanium
alloys, polypropylene, nylon, PMMA (polymethyl methacrylate),
medical grade silicone, e.g., Silastic.TM., available from Dow
Coming Corporation of Midland, Mich.; and polyurethane, e.g.,
Pellethane.TM., also available from Dow Corning Corporation.
[0122] In other embodiments, the devices of the exemplary
embodiments may comprise other types of biocompatible material,
such as, by way of example, polyvinyl alcohol, polyvinyl
pyrrolidone, collagen, heparinized collagen,
polytetrafluoroethylene, expanded polytetrafluoroethylene,
fluorinated polymer, fluorinated elastomer, flexible fused silica,
polyolefin, polyester, polysilicon, and/or a mixture of the
aforementioned biocompatible materials, and the like. In still
other embodiments, composite biocompatible material may be used,
wherein a surface material may be used in addition to one or more
of the aforementioned materials. For example, such a surface
material may include polytetrafluoroethylene (PTFE) (such as
Teflon.TM.), polyimide, hydrogel, heparin, therapeutic drugs (such
as beta-adrenergic antagonists and other anti-glaucoma drugs, or
antibiotics), and the like.
[0123] Referring in particular to FIGS. 4 and 9, in an exemplary
embodiment of the trabecular meshwork surgery, the patient is
placed in the supine position, prepped, draped and anesthetized as
necessary. In one embodiment, a small (less than about 1 mm)
incision, which may be self-sealing is made through the cornea 12.
The corneal incision can be made in a number of ways, for example,
by using a micro-knife, among other tools.
[0124] Advantageously, the embodiments of the self-trephine device
140 (FIG. 9) allow for a "one-step" procedure to make an incision
in the trabecular meshwork and to subsequently treat trabecular
meshwork with heating or vibrational energy to stimulate/rejuvenate
the tissue of trabecular meshwork leading to a more balanced
intraocular pressure (IOP). Desirably, this provides for a faster,
safer, and less expensive surgical procedure.
[0125] Ab Externo Insertion of Catheter via Small Puncture
[0126] Certain embodiments of such an ab externo insertion of a
catheter device via a small puncture are disclosed in copending
U.S. application Ser. No. 10/118,578, filed Apr. 8, 2002, entitled
GLAUCOMA STENT AND METHODS THEREOF FOR GLAUCOMA TREATMENT, the
entire contents of which are hereby incorporated by reference
herein.
[0127] In the ab externo procedure of FIGS. 6-8 and 10, the
respective device 92, 112, 130, 160 is inserted into Schlemm's
canal 21 with the aid of an applicator or delivery apparatus that
creates a small puncture into the eye 10 from outside. Since the
tissue surrounding the trabecular meshwork 21 is optically opaque,
an imaging technique, such as ultrasound biomicroscopy (UBM) or a
laser imaging technique, is utilized. The imaging provides guidance
for the insertion of the device.
[0128] FIG. 11 illustrates the implantation of any of the devices
92, 112, 130, 160 of respective FIGS. 6-8 and 10 using an ab
externo procedure having features and advantages in accordance with
one embodiment. In the ab externo procedure of FIG. 11, the devices
92, 112, 130, 160 are inserted into Schlemm's canal 21 with the aid
of an applicator or delivery apparatus 170 that creates a small
puncture into the eye 10 from outside.
[0129] Referring to FIG. 11, any of the devices 92, 112, 130, 160
is housed in or held by the applicator 170, and pushed out of the
applicator 170 once the applicator tip is in position within the
trabecular meshwork 21. Since the tissue surrounding the trabecular
meshwork 21 is optically opaque, an imaging technique, such as
ultrasound biomicroscopy (UBM) or a laser imaging technique, is
utilized. The imaging provides guidance for the insertion of the
applicator tip and the deployment of the devices 92, 112, 130, 160.
This technique can be used with a large variety of other device
embodiments with slight modifications since the trabecular meshwork
21 is punctured from the scleral side rather than the anterior
chamber side in the ab externo insertion.
[0130] Other Embodiments
[0131] The embodiment of FIG. 12 enables a completely ab interno
procedure that acts upon a limited segment of the Schlemm's canal
22. Both the inflow and outflow portions of the instrument or
device 180 are inserted through the trabecular meshwork 21 into
Schlemm's canal 22. Since the resistance to flow is greater through
the meshwork 21 than through the Schlemm's canal 22, inflow at the
point shown will travel around the Schlemm's canal 22 and then exit
through the aspiration outflow. This embodiment is particularly
well suited to treating or modifying the endothelial lining along a
short segment of Schlemm's canal 22.
[0132] In the embodiment of FIG. 13, retrograde injection into an
episcleral vein 182 is used to infuse a liquid into the Schlemm's
canal 22 via a minimally invasive minute puncture on the surface of
the eye 10. This provides a means to supply a flushing back flow to
flush the trabecular meshwork 21 (could be combined with anterior
chamber aspiration if the liquid volume was significant) and to
administer drugs or other chemicals directly to the Schlemm's canal
22. Since the flow resistance through the trabecular meshwork 21 is
greater than through the Schlemm's canal 22, this retrograde
injection would reach a significant fraction of the Schlemm's canal
22. This would also aid in the opening of the Schlemm's canal 22 if
it has shrunk as in trabeculectomy patients. This procedure could
also be combined with an episcleral ring that is pressed onto the
eye to occlude the venous system downstream of the injection point;
this would assist in achieving pressures that are high enough to
provide back flow through the trabecular meshwork 21.
[0133] In the embodiment of FIG. 14, a treatment ring or loop 190
is inserted into the anterior angle 25 using a deployment
instrument 200 (an embodiment of this instrument is shown in FIG.
15 and utilizes a plunger mechanism 202). The ring 190 when
deployed, expands and rests in the angle 25 near the trabecular
meshwork 21 and is preferably made from a material that absorbs and
slowly releases treatment agents to act on downstream structures
(trabecular meshwork, or endothelial lining, or Schlemm's canal, or
collector channels, etc.). The advantage is that the drug is
delivered directly upstream of where it is needed and naturally
flows to the desired downstream sites. This enables lower
concentrations of the treatment to be used and targets the desired
sites.
[0134] In the embodiment of FIG. 16, a stent is placed as a series
of add-on parts. A tubular (circular, inverted "U" shape, with or
without retention barbs, etc.) stent 210 is first inserted into
Schlemm's canal 22 to stent open the canal and support the
trabecular meshwork 21 for subsequent placement of a snorkel 212
(or multiple snorkels) that provide conduits for flow through the
trabecular meshwork 21 into Schlemm's canal 22 and prevent the
filling in of the trabecular meshwork 21. The Schlemm's canal stent
210 is inserted either via an ab externo or ab interno procedure.
The snorkel(s) 212 is (are) placed by first making an incision
through the trabecular meshwork 21 and the wall of the stent 210;
the snorkel(s) 212 is (are) then pushed through the trabecular
meshwork 21 until it (they) latches into the Schlemm's canal stent
210. Advantageously, the option to place multiple snorkels provides
a means to adjust the outflow resistance of the eye 10 in a series
of steps; use of snorkels with a variety of lumen diameters
provides finer or coarser flow adjustment. In addition, if a
snorkel were to become occluded (and could not be cleared) a
replacement snorkel could advantageously be placed adjacent to the
inoperative one to restore outflow.
[0135] In the embodiment of FIGS. 17A and 17B, a toggle-bolt shunt
220 is shown and relies on the expansion of ribs 222 to support it
in Schlemm's canal. The shunt 220 is inserted through the Schlemm's
canal 22 and trabecular meshwork 21 via an external procedure (ab
externo). Upon passing the tip 223 with flexible wings (or rim) 224
through the trabecular meshwork 21 into the anterior chamber 20,
the wings (or rim) 224 flex outward to prevent withdrawal. Turning
of a central bolt 226 (or pulling of a central rod as with a
pop-rivet) causes the ribs 222 to expand and occupy a portion of
the Schlemm's canal 22, providing support for the stent 220. The
central bolt or pin 226 is hollow (side ports 228 are included on
the bolt for the bolt style) to allow flow from the anterior
chamber 20 into Schlemm's canal 22. A modified embodiment, excludes
the flexible wings or rim at the tip and relies on adequate length
of the tip to protrude above the upper surface of the trabecular
meshwork 21. The small external puncture necessary to place this
stent could be filled, covered, or glued shut with a suitable
bio-glue. With some modification, this toggle-bolt approach could
also be accomplished via an ab interno approach.
[0136] The following embodiments of FIGS. 18 and 19 are tip
variations used for catheter based procedures on the Schlemm's
canal and trabecular meshwork. In each case, the catheter is guided
to the Schlemm's canal from an episcleral vein or portion of the
circulatory system further downstream or it is inserted through a
puncture in the scleral wall that reaches to the Schlemm's canal.
These procedures may be combined to form other multi-function
catheters as well, since many of these need not be positioned at
the tip of the catheter (they could be at some distance from the
tip).
[0137] In the embodiment of FIG. 18, a catheter device 230
comprises a thermal catheter tip 232 that is used to either cool or
heat the inner wall of Schlemm's canal 22 and the adjacent
trabecular meshwork 221. The effected damage to these tissues
provides improved flow into the Schlemm's canal 22 by reducing the
resistance to outflow through cell death. The induced healing
response may also result in healthier tissue.
[0138] In the embodiment of FIG. 19, a catheter device 240
comprises a vision catheter tip 242 having a lens 244 at a distal
end 246. The device 240 is used to inspect Schlemm's canal 22,
collector duct openings, and the adjacent trabecular meshwork 21.
This instrument 240 is useful to inspect these areas before,
during, or after treatment using the methods described above or
other methods. The vision tip 242 may also be combined with other
catheter embodiments to accomplish multi-function goals. This
catheter could also carry light or other therapeutic radiation to
the tip to be used for treatment of the Schlemm's canal or
trabecular meshwork.
[0139] From the foregoing description, it will be appreciated that
a novel approach for the surgical and therapeutic treatment of
glaucoma has been disclosed. While the components, techniques and
aspects of the invention have been described with a certain degree
of particularity, it is manifest that many changes may be made in
the specific designs, constructions and methodology herein above
described without departing from the spirit and scope of this
disclosure.
[0140] Various modifications and applications of the invention may
occur to those who are skilled in the art, without departing from
the true spirit or scope of the invention. It should be understood
that the invention is not limited to the embodiments set forth
herein for purposes of exemplification, but is to be defined only
by a fair reading of the appended claims, including the full range
of equivalency to which each element thereof is entitled.
* * * * *