Visual function after removal of subretinal neovascular membranes in patients with age-related macular degeneration

Background: Retinal pigment epithelial (RPE) cells have been transplanted to replace the RPE cells lost after surgical excision of choroidal neovascular membranes (CNV) associated with age-related macular degeneration. The purpose of this study was to analyze the visual function of eyes with altered RPE after surgical excision of choroidal neovascular membranes (CNV) associated with age-related macular degeneration, and to determine the effect of proliferated or migrated RPE cells on visual function. Methods: Forty-seven patients with age-related macular degeneration underwent excision of CNVs following vitrectomy and tamponade with sulfur hexafluoride (SF6) or silicone oil. The appearance of pre- or subretinal fibrosis and pigmentation of the lesion was considered to indicate proliferation and migration of RPE cells. Microperimetry was also performed. Results: A significant correlation was found between the size of CNVs removed by surgery and the size estimated by indocyanine green angiography (P=0.0126). The mean number of RPE cells lost was estimated at 1.52×104. Pre- or subretinal fibrosis or pigmentation was observed in 37 patients (75.5%). The number of eyes with fibrosis was significantly higher in eyes with silicone oil tamponade than with SF6 tamponade (P=0.0016). A statistically significant correlation was not found between the presence of fibrosis or pigmentation and the postoperative visual acuity. Not all patients used the area of pigmentation for fixation, and microperimetry showed that some of the patients had scotomas in well-pigmented areas. Conclusions: Fibrosis and pigmentation after excision of CNVs may not always indicate normal function in these areas. These observations are especially relevant for transplantation of pigment epithelial cells in the future.