PHOTORECEPTOR RESCUE IN THE DYSTROPHIC RETINA BY TRANSPLANTATION OF RETINAL-PIGMENT EPITHELIUM

This chapter describes the effects of retinal pigment epithelial (RPE) cell transplants in the retinas of Royal College of Surgeons (RCS) dystrophic rats. The chapter describes the mechanism by which RPE cell transplants affect the survival of photoreceptor cells in dystrophic retinas and in vitro. Retinal cell transplantation and techniques are also presented in the chapter. Prior to and during the early stages of the study of RPE cell transplantation, retinas as whole or partial segments or as cell suspensions had been grafted into mammalian eyes. Various methods were employed to transplant donor retinal tissue—intact or as a cell suspension—into a host eye. Often the donor tissue was of embryonic or neonatal origin, while the host animals were adults. The anterior chamber in rats was used as a suitable environment for retinal tissue transplantation. Small pieces of retina from newborn rats were transplanted into a retinal lesion bordered by the vitreous using a transscleral approach. Photoreceptor cells as an intact layer survived for several weeks when transplanted into light-damaged and dystrophic retinas. Exposing adult rats to excess light destroyed most photoreceptor cells within a few weeks, while the inner retina remained relatively unchanged. © 1992, Academic Press Inc.