Retinal cell grafts and instrument for implanting

Abstract

Surgical instruments, surgical techniques, retinal cell grafts, retinal cell and tissue isolation techniques, and a method for transplanting retinal cells, including photoreceptors, and / or retinal pigment epithelium, with the cells in the isolated tissue having their normal cell to cell configuration are disclosed.

Description

PRIORITY INFORMATION [0001] This application is a divisional of Ser. No. 10 / 323,958, filed Dec. 17, 2002, which is a divisional of Ser. No. 09 / 411,122 filed Oct. 4, 1999, now U.S. Pat. No. 6,579,256, which is a divisional of Ser. No. 08 / 322,735, filed Oct. 13, 1994, now U.S. Pat. No. 5,962,027, which is a continuation of Ser. No. 07 / 566,996 filed Aug. 13, 1990, abandoned, which is a continuation in part of Ser. No. 07 / 394,377, filed Aug. 14, 1989, abandoned, all of which are incorporated by reference as if reproduced in full below.BACKGROUND OF THE INVENTION [0002] The present invention relates in general to surgical instruments, surgical techniques, and cell and tissue isolation techniques. More particularly, the present invention is directed to a surgical tool for transplanting retinal cells, epithelium and choroidea within their normal planar configuration, a graft for transplantation to the subretinal region of the eye, a method for preparing such grafts for transplantation, and...

AI Technical Summary

Benefits of technology

[0012] Among the objects of the present invention, therefore, may be noted the provision of a method for preparation of a graft for use in the reconstruction of a dystrophic retina; the provision of such a method which conserves relatively large expanses of the tissue harvested from a donor eye; the provision of such a method in which the polarity and organization of the cells at the time of harvest are maintained in the graft; the provision of a graft for use in the reconstruction of a dystrophic retina; the provision of such a graft which facilitates regrowth of photoreceptor axons by maintaining the polar organization of the photoreceptor and the close proximity of their postsynaptic targets with the adjacent outer plexiform layer upon transplantation; the provision of a surgical tool for use in the transplantation method which allows appropriate retinotopic positioning and which protects photoreceptors or other grafted tissue from damage prior to and as the surgical device is positioned in the eye; and the provision of a method for transplantation of grafts to the subretinal area of an eye.

[0018] The present invention is further directed to an instrument for the implantation of an intact planar cellular structure between the retina and supporting tissues in an eye. The instrument comprises an elongate supporting platform for holding the planar cellular structure. The platform has a distal end for insertion into an eye, and a proximal end. The distal edge of the platform is convexly curved for facilitating the insertion of the platform into the eye and the advancement of the platform between the retina and the supporting tissues. The instrument has a side rail on each side of the platform for retaining the planar cellular structure on the platform, the distal ends of the side rails being rounded, and the distal portions of the side rails tapering toward the distal end of the platform to facilitate the insertion of the instrument between the retina and the supporting tissue.

[0020] The present invention is further directed to a kit for transplantation of a graft to the subretinal area of a host eye. The kit contains a graft comprising a population of cells selected from retinal cells, epithelial tissue and choroidal tissue, the population of cells being maintained in the same organization and cellular polarity as is present in normal tissue of that type. The kit additionally contains a surgical instrument comprising an elongate tube, having a flat, wide cross-section, with a top, a bottom for supporting the planar cellular structure, and opposing sides. The tube has a beveled distal edge facilitating the insertion of the tube into the eye and the advancement of the tube between the retina and the supporting tissues. The surgical instrument also comprises plunger means for ejecting a planar cellular structure from the distal end of the tube.

Problems solved by technology

In an effort to recover what was previously thought to be an irreparably injured retina, researchers have suggested various forms of grafts and transplantation techniques, none of which constitute an effective manner for reconstructing a dystrophic retina.

However, this method destroys the cellular polarity and native organization of the donor retinal pigment epithelium which is desirable for transplants.

While del Cerro reports that the intraocular transplantation of retinal strips can survive, he notes that the procedure has some definite limitations.

For instance, his techniques do not allow for the replacement of just the missing cells (e.g. photoreceptors) but always include a mixture of retinal cells.

Thus, with such a transplant appropriate reconstruction of the dystrophic retina that lacks a specific population of cells (e.g., photoreceptors) is not possible.

Furthermore, no means of isolating and purifying any given population of retinal cells (e.g. photoreceptors) from other retinal cells was demonstrated.

This conclusion is based on the well known optical characteristics of photoreceptors (outer segments act as light guides) and clinical evidence showing that folds or similar, even minor disruptions in the retinal geometry can severely degrade visual acuity.

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