Pressure relieving device and process for implanting

Abstract

This invention involves a porous device for implantation in the scleral tissue of the eye to relieve the intraocular pressure of glaucoma and a method for surgically implanting the device.

Description

26 to allow rapid flow of fluid through the spaces 28 between the fibers. The meshwork of fibers 26 being made of a biocompatible material would be flexible. The meshwork would allow fluid flow to the vertically cut edges of the implant and the sclera.

Another way to achieve porosity would be through a system of channels 30 through the implant. A variety of patterns could be cut so as to achieve high fluid flow through the implant to the vertically cut edges. For example, a fan shaped system 32 of drilled holes or a grid pattern of drilled holes from front to back or an interlocking pattern drilled from side to side, etc. could be used. The purpose and design are such that fluid could pass through, as described above, and the implant would resist collapse from the imposed pressure.

A typical operation for inserting the preferred embodiment of the invention follows: After retrobulbar anesthesia, the superior rectus muscle is placed on a four O silk bridal suture. Following this, a conjunctival flap is raised starting at the superior rectus and working forward to This is then reflected back to the cornea. Cautery is used to obtain hemostasis and to outline the location of the placement for the implant. A rectangular area, 5 mm by 3 mm, is outlined using a 64 Beaver blade. A small groove is made on the sclera side to half the depth of the sclera. This is grasped at one corner and the flap is dissected anteriorly until the rectangular flap is completely raised in the clear cornea. At this point a 75 blade is used to make a stab incision into the anterior chamber of the eye and a 1 by 4 mm section of the cornea and trabecular meshwork are excised en bloc.

Using a lamellar dissecting blade, attention is turned to the posterior aspect of the bed of the rectangular flap. Further dissection at the base is carried posteriorly for approximately 0.5 millimeter. The implant is then placed into position in this bed with the inferior posterior flap laid into the groove that has just been created on the posterior aspect of the bed. The anterior portion is in direct communication with the anterior chamber. The scleral flap is then laid over this implant and tucked in underneath the superior flanges that are present. If necessary, a portion of the scleral flap can be excised so that the sclera lays down smoothly over the implant. The implant is then sutured to the sclera on both sides with a 10-O nylon suture through the fixation holes in the superior flange. The conjunctival tissue is then sutured back together with a 6-O-plain gut running suture.

Claims

1. A device for relieving intraocular pressure comprises a body portion and wall portions in the form of a hexahedron; at least the body portion composed of a biocompatible porous material; said device adapted to be implanted within the scleral tissue of the eye with at least one edge of the device at an opening of, with no substantial extension into, the anterior chamber and adjacent to the area where the sclera makes the transition into clear cornea of the eye; the pores of the body portion are of such size and quantity as to permit drainage of fluid from the anterior chamber to the scleral tissue without collapse of the anterior chamber.

2. A device as in claim 1 wherein one face of the hexahedron is said body portion has a first surface, said first surface of said body portion being sloped to overlie the opening into the anterior chamber to direct fluid from the anterior chamber into the body portion of the device.

3. A device as in claim 1 wherein at least one edge of one wall portion of the device at least one edge of one wall portion the top surface of the device is extended for anchoring the device in position.

4. A device as in claim 1 wherein the three edges of three wall portions of the top surface of the device, other than an the edge at the opening of the anterior chamber, are extended for anchoring the device in position.

5. A device as in claim 1 wherein a thin flange extends from four sides of the base of the device, the flange at the posterior side of the device being raised and held in position by extensions of the vertical walls of said device four sides of the base of device, the flange at the posterior side of the device being raised and held in position by extensions of the vertical walls of said device.

6. A method for reducing intraocular pressure comprising the steps of:

creating a scleral flap by making an incision in the sclera substantially adjacent to the limbus of the eye;

excising a block of sclera by making a second incision into the sclera underneath the previously produced scleral flap but extending into the cornea and entering the anterior chamber at substantially the area where sclera becomes cornea to provide a pocket in the sclera and a shelf in the cornea and to provide a window providing direct fluid contact with the anterior chamber of the eye;

providing a device for relieving intraocular pressure, said device comprising a body portion composed of a biocompatible porous material, said body portion comprising a first end portion and a second end portion, said body portion defining pores therethrough, said pores being of such size and quantity as to permit drainage of fluid from the anterior chamber to the scleral tissue without collapse of the anterior chamber; and

placing said device for relieving intraocular pressure the hexahedrally shaped device of claim 1 in said pocket of the sclera whereby said first end with the anterior portion of said device is positioned in said shelf of the cornea such that said first end portion is adjacent said window and is in direct fluid contact with the anterior chamber without extending substantially into the anterior chamber and whereby said second end portion is with the remaining portions of the device positioned within the sclera.

7. A device for relieving intraocular pressure comprising a body portion constructed of a biocompatible material having flow passages therein; said flow passages selected from the group consisting of pores, openings, channels and spaces between fibers in a meshwork of fibers; said device having a substantially uniform cross-section adapted to be fitted within the scleral tissue of the eye at an area adjacent an opening of, with no substantial extension into, the anterior chamber of the eye at a first position adjacent to the area of the eye where the sclera makes the transition into clear cornea of the eye; and extending to a second position within the scleral tissue of the eye, the distance between said first and second positions defining the length of the body portion through which fluid can flow, said length being approximately six (6) millimeters; said flow passages being of such size and quantity as to permit drainage of fluid from the anterior chamber to the scleral tissue without collapse of the anterior chamber.8. A method for reducing intraocular pressure within the anterior chamber of an eye, said method comprising the following steps

a. creating a scleral flap by making an incision in the sclera of the eye substantially adjacent to the limbus of the eye;

b. excising a block of scleral tissue by making a second incision into the sclera underneath the previously produced scleral flap but extending into the cornea and entering the anterior chamber at substantially the area where sclera becomes cornea to provide a pocket in the sclera and a shelf in the cornea, c. placing a device for relieving intraocular pressure, said device comprising a body portion constructed of a biocompatible material; and having flow passages therein; said device having a first end portion and a second end portion with said flow passages therebetween; and

d. the device being placed in said pocket of the sclera with said first end portion of said device positioned in said shelf of the cornea whereby said first end portion of said body portion is in direct fluid contact with the anterior chamber of the eye without substantial extension into the anterior chamber of the eye and with the second end portion of said device positioned within the sclera of the eye to permit drainage of fluid from the anterior chamber into the scleral tissue without collapse of the anterior chamber.