RETINAL TRANSPLANTATION - A REVIEW

Background The objective of recent animal experimental studies is to s ubstitute destroyed or degenerated retina and to improve visual functi on by transplanting retinal components. Mature or immature retinal com ponents were transplanted into the subretinal space of different anima l species. Methods Embryonic and non-embryonic retina components of di fferent animals or of humans are used as grafts. They are transplanted to adult host animals. There is the possibility of utilizing a poster ior transscleral approach or a vitreoretinal approach. The latter offe rs a better visual control. Transplantation of retinal pigment epithel ium could rescue photoreceptors in adult rats with inherited or age-re lated macular degeneration. Results After the transplantation it was p ossible to measure significantly higher visual evoked potentials in th e transplanted eye than in the untreated fellow eye. Additionally, an almost normal pupillary reflex was identified. As it is not possible t o adequately determine visual acuity in rodents, it is necessary to ex amine, as to whether visual improvement is also evident in primates.Co nclusion The eye is an immunologically privileged location for transpl ants because of retinal autoantigenic specific immunsuppression that p rotects the transplant from immunologic rejection. Many questions rega rding operation technique, gaining of transplantation tissue and immun oreaction are to be answered before the use is possible on humans. The counseling of the patients and the informational policies towards the media should be correspondingly retentive.