Comparison of external and internal approaches for transplantation of autologous retinal pigment epithelium.

The feasibility of autologous transplantation of retinal pigment epithelial (RPE) cells from just posterior to the ora serrata to the posterior pole was demonstrated in the rabbit model. Two techniques for introducing the transplanted cells were compared: an internal (anterior transvitreal) and an external (posterior transscleral) penetration to the subretinal space. In both approaches, RPE cells were obtained by biopsy from the peripheral retina of a rabbit eye, cultured, labeled with a fluorescent dye and 3H-thymidine, and transplanted to the posterior pole of the same or contralateral eye. The external approach consistently resulted in a greater number of transplanted cells on Bruch's membrane. The internal technique was more precise because it permitted direct visualization of the placement of the transplanted RPE. Transplantation of autologous RPE is a possibility that should be further pursued.