WO2011089605A2

WO2011089605A2 - Ocular shunt

Info

Publication number: WO2011089605A2
Application number: PCT/IL2011/000070
Authority: WO
Inventors: Adiel Barak
Original assignee: The Medical Research, Infrastructure, And Health Services Fund Of The Tel Aviv Medical Center
Priority date: 2010-01-22
Filing date: 2011-01-20
Publication date: 2011-07-28
Also published as: WO2011089605A3

Abstract

The invention provides an ocular shunt (2) for draining fluid from an eye. The shunt has a tubular portion (8) having a cross - section having an outer contour that is elongated and non - circular. Use of a shunt having an elongated and non- circular cross section tends to reduce trauma to the nerve fibers of the retina. The invention also provides a delivery device for implanting the ocular shunt of the invention in an eye, and a system for treating an eye comprising the shunt of the invention and a delivery device of the invention.

Description

OCULAR SHUNT

FIELD OF THE INVENTION

This invention relates to medical devices, and more specifically to such devices for treating an eye.

BACKGROUND OF THE INVENTION Aqueous fluid is made continuously, and circulates throughout the eye before draining though the canals of Schlemm in the anterior chamber of the eye. When too much fluid is produced, or is not adequately drained, the intraocular pressure (IOP) rises, which can lead to glaucoma. Normal intraocular pressure is below 21 mm/Hg. Glaucoma develops at IOPs higher than 21 mm/Hg. However, approximately 20% of glaucoma patients never have pressures higher than 21 mm/Hg, not all of those who do have pressures higher than 21 mm/Hg suffer from glaucoma.

Glaucoma is a potentially blinding group of diseases affecting 2-3% of the United States population. The disease involves loss of retinal ganglion cells from the optic nerve in a characteristic pattern of optic neuropathy, caused by elevated intraocular pressure. Untreated glaucoma leads to permanent damage of the optic nerve and resultant visual field loss, which can progress to severe blindness

The treatment of glaucoma focuses on lowering the IOP, thus preventing progressive loss of the visual field. Pharmacological treatment of glaucoma involves topical application of of medications consisting of beta blockers, prostaglandins analogues, a-2 agonists, and cabonic anhydrase inhibitors. Another approach to the treatment of glaucoma is trabeculoplasy in which part of the trabeculae meshwork around the entrance to the canals of Schlemm is destroyed using argon laser radiation. It is also known to implant a shunt in the eye that creates an artificial drainage site for aqueous fluid. One type of ocular shunt, for example, as disclosed in US Patent No. 7,837,644 to Pinchuk, is implanted in the eye on opposite sides of the sclera in the vicinity of the angle of the eye. It is also known to implant a shunt on the inner surface of the sclera in a suprachoroidal space and opening to the anterior chamber, for example, as disclosed in US Patent No. 7,291,125. US Patent No. 7,354,416 to Quiroz- Mercado discloses another type of shunt that is implanted in the posterior chamber of the eye. The shunt is inserted into the lamina cribosa which is a collagenous tissue overlying the optic nerve. Depending on the angle of insertion, the implanted shunt may reside entirely inside the optic nerve, or may protrude through the wall of the optic nerve.

SUMMARY OF THE INVENTION

In its first aspect, the present invention provides an ocular shunt that is inserted into the wall of the eyeball. The implant may be used, for example, to treat glaucoma.

The shunt of the invention is adapted to be inserted into the sclera of an eye, and may be implanted in the sclera of the posterior chamber of the eye. The body of the shunt has a hollow tubular portion part of which resides in the sclera in a generally radial orientation to allow fluids to drain from the interior or the eye to the external space.

In accordance with the invention, the outer surface of the tubular portion has a non-circular, elongated, slender cross section. For example, the outer contour of the cross section of the tubular portion may be elliptical, oval or formed from two parallel lines joined by two arcs. As additional examples of the outer contour of the cross section of the tubular portion, the outer contour may a lentil-like shape formed by two arcs, or a diamond or parallelogram shape. The inventor has found that use of a shunt having a tubular portion having an outer surface whose cross section is elongated and slender tends to reduce trauma to the nerve fiber layers of the retina in comparison with shunts whose tubular portion is circular.

The invention also provides a delivery device for implanting a shunt of the invention in the sclera of an eye. The delivery device has a shaft having an outer surface that conforms to the inner surface of the tubular portion of the shunt so that the shunt can be mounted onto the shaft and immobilized on the shaft. The shaft terminates in a beveled tip that is used to pierce the sclera during implantation of the shunt.

In another of its aspects, the invention provides a method for deploying a shunt of the invention in an eye. In accordance with this aspect of the invention, a shunt of the invention is mounted onto a delivery device of the invention, and the tip of the delivery device is inserted into the eye through a small cut in a portion of the sclera outside the anterior chamber of the eye, approximately 3 mm from the end ot the anterior chamber. The tip of the delivery device is advanced through the posterior chamber. The tip of the delivery device is then used to pierce a hole in the retina, choroid and then in the wall of the eye in the posterior chamber near the optic nerve head. The shunt is then slipped off the tip of the delivery device into the wall of the eye. After implantation in the wall of the posterior chamber, the shunt passes through the retina, choroid, and sclera, permitting aqueous humor to flow out from the posterior chamber to the exterior space.

Thus, in its first aspect, the present invention provides an ocular shunt for draining fluid from an eye comprising a tubular portion, the tubular portion having an exterior end and an interior end and surrounding an inner lumen, and the tubular portion having a cross-section having an outer contour that is elongated and non-circular.

The ocular shunt of the invention may further comprising an interior flange adjacent to the interior end of the tubular portion. The shunt may also comprise an exterior flange mounted on the tubular portion and separated from the interior flange so as to define a sclera section of the tubular portion between the exterior flange and the interior flange, and to further define an exterior section of the tubular portion between the exterior end of the tubular portion and the exterior flange. The shunt may comprise a plurality of pores in the exterior section of the tubular portion.

The elongated outer contour of the cross section of the tubular portion may be slender. For example, the outer contour of the tubular portion may have an elliptical or oval cross section, a shape formed from two parallel surfaces joined by two arcs, a lentil-like shape formed by two arcs or a diamond or parallelogram shape.

At least a portion of the outer surface of the tubular portion may be coated with a polymeric material. The outer surface of the shunt may be provided with one or more resiliently flexible wings to secure the shunt in the wall of the eye.

The invention also provides a delivery device for implanting an ocular shunt in an eye, the device comprising a shaft having an outer surface that is non-circular and elongated. The shaft may be hollow, or may be a solid rod. The delivery device may have a sharp tip.

The invention further provides a system for treating an eye, comprising:

(a) an ocular shunt for draining fluid from an eye comprising a tubular portion, the tubular portion having an exterior end and an interior end and surrounding an inner lumen, and the tubular portion having a cross-section having an outer contour that is non-circular and elongated; and

(b) a delivery device for implanting the ocular shunt in an eye, the device comprising a shaft having an outer surface adapted for mounting the shunt on the shaft.

The invention also provides a method for deploying a shunt in an eye, the shunt comprising a tubular portion, the tubular portion having an exterior end and an interior end and surrounding an inner lumen, and the tubular portion having a cross-section having an outer contour that is non-circular and elongated, the method comprising:

(a) mounting the shunt on a delivery device, a shaft of the delivery device having an outer surface adapted for mounting the shunt on the shaft, and the delivery device having a sharp tip;

(b) piercing a small hole in the wall of the posterior at an implantation site with the sharp tip with the delivery device to form a hole in the wall of the exterior chamber; and

(c) pushing the shunt off the delivery device into the hole in the wall of the posterior chamber.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to understand the invention and to see how it may be carried out in practice, embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:

Fig. 1 shows an ocular shunt for draining fluid from an eye in accordance with one embodiment of the invention;

Fig. 2a shows a cross section of a shunt of the invention having an oval or elliptical cross section, Fig. 2b shows a cross section of a shunt of the invention having a flat cross section, Fig. 2c shows a shunt of the invention having a lentil like cross section, and Fig. 2d shows a shunt of the invention having a diamond or parallelogram cross section;

Fig. 3a shows a delivery device for implanting a shunt of the invention in an eye and Fig. 3b shows the delivery device of Fig. 3a after mounting of a shunt of the invention;

Fig. 4 shows a method of implanting a shunt of the invention in an eye; and

Fig. 5 shows a shunt of the invention after implantation in the posterior chamber of the eye.

DETAILED DESCRIPTION OF EMBODIMENTS

Fig. 1 shows an ocular shunt 2 in accordance with one embodiment of the invention. The shunt 2 is adapted to be inserted into the sclera of an eye. The shunt 2 has an interior end 4 which, and after implantation of the shunt, is positioned in the interior of the eye. The shunt 2 also has an exterior end 6 which, after implantation, is positioned in the exterior of the eye. The body of the shunt has a hollow tubular portion 8 having a length somewhat longer than thickness of the sclera in which the shunt is to be implanted. An interior flange 10 at the interior end surrounds an interior opening (not seen in the perspective of Fig. 1) of the tubular portion. An exterior flange 12 is positioned on the tubular portion and defines a section of the tubular portion between the interior and exterior flanges referred to herein as the sclera section 14 of the tubular portion. The interior and exterior flanges can be perpendicular to the longitudinal axis of the tubular portion when the shunt 2 is to be implanted in the wall of the eye in an essentially radial orientation. The interior and exterior flanges are preferably separated from each other by a distance substantially equal to the thickness of the sclera in which the shunt is to be implanted. An exterior section 16 of the tubular portion extends from the exterior flange to the exterior end of the tubular portion. As explained below, aqueous fluid in the interior of the eye enters the interior opening of the tubular portion, flows through the sclera section of the tubular portion and then exists the shunt into the exterior space through an exterior opening 18 and through pores 20 in the wall of the exterior section 16 of the tubular portion 8 that extends into the exterior space after implantation.

The sclera section 14 of the shunt may be coated with a polymeric material to increase friction between the sclera section 14 and the sclera of the eye after implantation in the sclera, in order to reduce or prevent migration of the shunt in the eye after implantation. The polymeric coating may have a rough surface or may contain one or more ridges or grooves to further increase friction between the shunt surface and the sclera. The sclera section may be provided with one or more resiliently flexible wings 19 extending from the outer surface of the sclera section 14 of the tubular portion and extending towards the interior end of the shunt to immobilize the shunt in the eye. Alternatively or additionally, the exterior section 16 section may be provided with one or more resiliently flexible wings 21 extending from the outer surface of the exterior section 16 of the tubular portion and extending towards the interior end of the shunt to prevent movement of the shunt 2 towards the interior of the eye after implantation.

In accordance with the invention, the outer surface of the tubular portion 8 has a non-circular, elongated slender cross section. Fig. 2 shows several examples of cross sections of the tubular portion in accordance with the invention. Fig. 2a shows a cross section 22 of a tubular portion whose outer contour has an elliptical or oval cross section. Fig. 2b shows a cross section 24 of a tubular portion whose outer contour has a shape formed from two parallel surfaces 25 and 27 joined by two arcs 29a and 29b. Fig. 2c shows cross section 30 of a tubular portion whose outer contour has a lentil-like shape formed by two arcs 32a and 32b. Fig. 2d shows a cross section 34 whose outer contour 36 has a diamond or parallelogram shape.

Fig. 2 also shows the orientation of nerve fibers 23 in the retina around each of the cross sections 22, 24, 30 and 34. A shunt having a tubular portion having a slender elongated cross-section tends to reduce trauma to the nerve fibers layer of the retina in comparison with shunts whose tubular portion is circular.

The implant 2 is deployed using a delivery device 40 shown in Fig. 3a. The delivery device 40 has a slender shaft 42 that that may be solid or hollow. The shaft terminates at a handle portion 43 at a proximal end 44. At a distal end 48, the shaft 42 is beveled to provide a sharp tip 43 that is used to pierce the sclera during implantation of the shunt 2, as explained below. The implant 2 is mounted onto the distal end of the delivery device 20, near the distal end, with the exterior end 6 of the implant 2 adjacent to the distal end of the device. The outer surface of the shaft is selected to allow a shunt of the invention to be firmly mounted onto the shaft. Thus, for example, a delivery device having a shaft with an outer surface having an oval cross section could be used to implant the shunt 2 shown in Fig. 1. Fig. 3b shows the shunt 2 after mounting onto the delivery device 40. The implant 2 is reversibly secured to the delivery device 40 so as to prevent longitudinal and rotational movement of the implant 2 on the device 40 during delivery of the implant to the site of its implantation.

In another of its aspects, the invention provides a method for deploying a shunt of the invention in an eye. Before inserting the implant, vitreous removal surgery may be performed to reduce the chances of plugging of the implant with vitreous tissue. Fig. 4 shows one stage in a method for deploying the shunt 2 in an eye 50, using the delivery device 40, in accordance with one embodiment of this aspect of the invention. The sharp tip 43 of the delivery device is inserted into the eye through a small cut 41 in the sclera at a location overlying the site 49 in the posterior chamber 47 where the shunt 2 is to be implanted. The cut may be, for example around 1.2 mm in length or less. The distal end of the delivery device 40 with the mounted shunt 2 is then advanced through the pars plana 51 of the eye, into the posterior chamber 47. The sharp tip of the delivery device is used to pierce a small hole in the wall of the posterior at the implantation site 49. The shunt is then pushed off the distal end of the delivery device into the hole in the wall of the posterior chamber.

Fig. 5 shows the intraocular implant 2 after implantation into the eye 50. The implant 2 passes through the retina, choroid, and sclera, permitting aqueous humor to flow from the posterior chamber 52 to the exterior space 54. The lateral pores 20 facilitate aqueous drainage into the external space 54. Since the shunt 2 is longer than the thickness of the sclera, the chances of closure or extrusion of the lumen of the tubular portion 8 tend to be reduced.

The implantation of the shunt of the invention is minimally invasive, and may require only local anesthesia. Retrobulbar anaesthesia is often not necessary, and thus the chances of iatrogenic damage to the optic nerve can be reduced or eliminated. Aqueous fluid is drained out of the eye through the wall of the eye at a location that is not on the exposed portion of the eye surface. Thus visible bleb or any signs of tissue abnormality are usually not observed, so that discomfort and the chances of complications tend to be reduced. Placing the shunt-tube of the invention into the orbital tissue of the eye to drain intraocular fluids, may have several advantages: 1. The drainage is preformed away from the outer surface, thus the chances of infection are reduced.

2. The intraocular fluids are drained by the orbital veins into the general circulation, thus there is no connection to the conjunctival tissue, and the state of the conjuctiva does not limit the surgical outcome.

3. The orbital tissue into which fluids are drained has very poor sensory nerve endings, thus reducing long term discomfort .

4. By placing the tube next to the optic nerve and to the retinal ganglion cell layer, the pressure control is close to the optic nerve which is the organ most susceptible to damage by elevated intraocular pressure.

Claims

CLAIMS:

1. An ocular shunt for draining fluid from an eye comprising a tubular portion, the tubular portion having an exterior end and an interior end and surrounding an inner lumen, and the tubular portion having a cross-section having an outer contour that is elongated and non-circular.

2. The ocular shunt according to Claim 1 further comprising an interior flange adjacent to the interior end of the tubular portion.

3. The ocular shunt according to Claim 1 further comprising an exterior flange mounted on the tubular portion and separated from the interior flange so as to define a sclera section of the tubular portion between the exterior flange and the interior flange, and to further define an exterior section of the tubular portion between the exterior end of the tubular portion and the exterior flange.

4. The ocular shunt according to Claim 3 further comprising a plurality of pores in the exterior section of the tubular portion.

5. The ocular shunt according to any one of the previous claims wherein the elongated outer contour of the cross section of the tubular portion is slender.

6. The ocular shunt according to any one of the previous claims wherein the outer contour of the tubular portion has an elliptical or oval cross section.

7. The ocular shunt according to any one of Claims 1 to 5 wherein the outer contour of the tubular portion has a shape formed from two parallel surfaces joined by two arcs.

8. The ocular shunt according to any one of Claims 1 to 5 wherein the outer contour of the tubular portion has a lentil-like shape formed by two arcs.

9. The ocular shunt according to any one of Claims 1 to 5 wherein the outer contour of the tubular portion has a diamond or parallelogram shape.

10. The ocular shunt according to any one of the previous claims wherein at least a portion of the outer surface of the tubular portion is coated with a polymeric material.

11. The ocular shunt according to any one of the previous claims wherein the outer surface of the shunt is provided with one or more resiliently flexible wings to secure the shunt in the wall of the eye.

12. A delivery device for implanting an ocular shunt in an eye, the device comprising a shaft having an outer surface that is non-circular and elongated.

13. The delivery device according to Claim 12 wherein the shaft is hollow.

14. The delivery device according to Claim 12 wherein the delivery device is a solid rod.

15. The delivery device according to any one of Claims 12 to 14 having a sharp tip.

16. A system for treating an eye, comprising:

17. A method for deploying a shunt in an eye, the shunt comprising a tubular portion, the tubular portion having an exterior end and an interior end and surrounding an inner lumen, and the tubular portion having a cross-section having an outer contour that is non-circular and elongated, the method comprising:

(b) pierceing a small hole in the wall of the posterior at an implantation site with the sharp tip with the delivery device to form a hole in the wall of the exterior chamber; and