Five-year follow-up of fellow eyes of patients with age-related macular degeneration and unilateral extrafoveal choroidal neovascularization. Macular Photocoagulation Study Group.

OBJECTIVES: To assess the visual prognosis of patients with age-related macular degeneration and unilateral extrafoveal choroidal neovascularization (CNV), and to determine the risk of CNV developing in fellow eyes that were initially unaffected.

DESIGN, PATIENTS, AND SETTING: Five-year prospective follow-up study of fellow eyes of 228 patients enrolled in a randomized clinical trial of laser photocoagulation of extrafoveal CNV. Visual acuity was measured and macular photographs were taken at 6-month intervals.

MAIN OUTCOME MEASURES: Five-year change in visual acuity of fellow eyes from baseline, incidence of legal blindness (visual acuity of < or = 20/200 in the better eye), and cumulative incidence of CNV in fellow eyes free of neovascular maculopathy at the time of study enrollment.

RESULTS: Photographically documented CNV developed in 33 (26%) of 128 fellow eyes that were initially free of neovascular maculopathy, and was associated with poor visual acuity at the end of the 5-year follow-up period. Among 67 patients who had bilateral neovascular maculopathy initially and were examined 5 years later, 33 (49%) were legally blind compared with 13 (12%) of 106 patients who had unilateral neovascular maculopathy initially. In all 13 of the latter group, CNV had developed in the fellow eye.

CONCLUSIONS: Patients with age-related macular degeneration and CNV in one eye are at high risk of legal blindness within 5 years, and, thus, should be followed up carefully to ensure that laser treatment can be applied to CNV in either eye whenever it is likely to improve the visual prognosis.