TRANSPLANTATION OF FETAL RETINAL-PIGMENT EPITHELIUM IN AGE-RELATED MACULAR DEGENERATION WITH SUBFOVEAL NEOVASCULARIZATION

Background: Age-related macular degeneration (ARMD) is caused by abnor mal retinal pigment epithelium (RPE) and may be complicated by choroid al neovascularization. The object of treatment would be to replace the diseased RPE with normal human RPE. Method: Five patients with ARMD ( preoperative visual acuity 0.08-0.2) underwent removal of subretinal f ibrovascular membranes using pars plana vitrectomy techniques. Human f etal RPE (15-17 weeks gestational age) was cultured and transplanted a s a monolayer patch into the subretinal space. Transplants were follow ed by funduscopy and fluorescein angiography. Macular function was ass essed using scanning laser ophthalmoscopic (SLO) microperimetry. Resul ts: Three RPE transplants were placed in the fovea; two were placed pa rafoveally. All transplants have survived for 3 months. They have grow n and increased in size covering part of the epithelial defect caused by removal of the fibrovascular membrane. SLO microperimetry indicated that visual function was present in four of the transplants at 1 mont h but in only two at 3 months after surgery. Function over the transpl ants, especially those in the fovea, was compromised by cystoidlike ma cular edema. Conclusions: Human fetal RPE transplants survive well in the macula for as long as 3 months. They are capable of growing to cov er epithelial defects caused by removal of subretinal neovascular memb ranes. The causes for development of macular edema in transplants dire ctly in the fovea warrant further evaluation.