Objective: To determine the incidence and visual impact of and risk factors for persistent and recurrent neovascularization after laser photocoagulation of subfoveal choroidal neovascularization (CNV) in patients with age-related macular degeneration.
Design, patients, and methods: The records of 189 eyes in the Subfoveal New CNV Study and 100 eyes in the Subfoveal Recurrent CNV Study assigned to laser photocoagulation were examined. Persistent CNV (detected within 6 weeks of treatment) and recurrent CNV (detected after 6 weeks) were defined angiographically by fluorescein leakage from the periphery of the treatment scar. Incidence was estimated using survival analysis methods.
Results: In both studies, persistent CNV was observed in approximately 13% of the eyes, and recurrent CNV was estimated to have developed by 3 years in an additional 35% of the eyes. In the New CNV Study, by 3 years, 36% of the eyes with persistent CNV had lost 6 or more lines of visual acuity as had 19% of the eyes with recurrent CNV and 27% of the eyes without persistence or recurrence. The presence of neovascular maculopathy in the fellow eye was associated with an increased risk for persistence or recurrence in the study eye. In the New CNV Study, partial coverage of the lesion with heavy laser treatment and/or runoff was associated with increased risk for persistence; less extensive natural scarring of the lesion at study entry was associated with increased risk for recurrence.
Conclusions: Close to half of the eyes treated for subfoveal CNV have persistent or recurrent CNV within 3 years. There is a strong association between neovascular maculopathy in the fellow eye and the inability of laser photocoagulation to permanently obliterate signs of CNV from the study eye. Within these two studies, there was little additional damage to visual function resulting from persistent or recurrent neovascularization. There appears to be no reason to deviate from the protocol goal of covering the entire neovascular complex when treating eyes with subfoveal CNV.