In a randomized clinical trial, the effects of laser treatment of subfoveal recurrent neovascularization have been compared with no additional laser treatment. Among eyes with age-related macular degeneration assigned to laser treatment of recurrent neovascularization (n = 97) and those assigned to no additional laser treatment (n = 109), average visual acuity was 20/125 (Snellen equivalent) at entry. Both at 3 and 24 months after enrollment, the average visual acuity of laser-treated eyes was 20/250, indicating a decrease in visual acuity of 3 lines immediately after treatment, but little further decrease in acuity thereafter. In contrast, the average visual acuity of eyes assigned to no additional treatment decreased by 2 lines to 20/200 by 3 months after entry. After 24 months, acuity had decreased an additional 2 lines to 20/320. By 24 months after enrollment, only three (9%) of 35 laser-treated eyes, but 13 (28%) of 46 untreated eyes, had decreased visual acuity of 6 or more lines from baseline (P = .03, chi 2 test). On average, treated eyes maintained the initial contrast threshold for large letters, while the contrast threshold of untreated eyes worsened steadily throughout 24 months of follow-up. This study was halted before the target number of patients had been enrolled because of the similarity of these findings to findings from a related Macular Photocoagulation Study clinical trial of laser treatment of subfoveal neovascularization secondary to age-related macular degeneration in eyes without previous laser treatment. Laser treatment is recommended for subfoveal recurrent neovascularization in eyes with age-related macular degeneration that meet the eligibility criteria for this study.