RETINAL-PIGMENT EPITHELIAL REPOPULATION IN MONKEYS AFTER SUBMACULAR SURGERY

Background: Transplantation of retinal. pigment epithelium may be a tr eatment for retinal diseases, such as age-related macular degeneration and hereditary macular degeneration. Before transplantation studies a re undertaken, questions concerning repopulation of retinal pigment ep ithelial cells in situ and photoreceptor repair after submacular surge ry need to be addressed. Methods: We removed the retinal pigment epith elium from Bruch's membrane in the macaque monkey in the macula and ou tside the vascular arcades. This model allowed the study of in situ re tinal pigment epithelium regrowth and photoreceptor repair for 9 month s following debridement. Results: Fluorescein angiography revealed a w indow defect in the area of denuded retinal pigment epithelium. Histol ogic studies revealed repopulated nonpigmented retinal pigment epithel ial cells in the denuded areas in both the early and late periods. At 9 months, the repopulated retinal pigment epithelium was associated wi th repaired, normal-appearing photoreceptor outer segments. Retinal pi gment epithelium regrowth was observed only if Bruch's membrane was in tact. Conclusions: Repopulation of retinal pigment epithelium in the a dult primate can occur rapidly and can support the repair of damaged p hotoreceptors following submacular surgery.