Objectives: To verify and quantify previously reported risk factors for development of choroidal neovascularization (CNV) in the fellow eye of patients with 1 eye affected with CNV secondary to age-related macular degeneration, to examine the value of characteristics of the pericentral macula in the quantification of risk for developing CNV, and to explore whether the presence of occult CNV in the first eye affects the development of CNV in the fellow eye.
Design, patients, and setting: Follow-up study of fellow eyes of 670 patients enrolled in multicenter, randomized clinical trials of laser photocoagulation of juxtafoveal or subfoveal CNV.
Main outcome measure: Development of CNV.
Results: Three characteristics of the central macula of the fellow eye and 1 systemic factor were associated independently with an increased risk of developing CNV: the presence of 5 or more drusen (relative risk, 2.1; 95% confidence interval, 1.3-3.5), focal hyperpigmentation (relative risk, 2.0; 95% confidence interval, 1.4-2.9), 1 or more large drusen (relative risk, 1.5; 95% confidence interval 1.0-2.2), and definite systemic hypertension (relative risk, 1.7; 95% confidence interval, 1.2-2.4). Estimated 5-year incidence rates ranged from 7% for the subgroup with no risk factors to 87% for the subgroup with all 4 risk factors. Characteristics of the pericentral macula were not strongly associated with the development of CNV. The presence of occult CNV in the first eye affected had no influence on the development of CNV or on the type of CNV in the fellow eye.
Conclusions: The prognosis of the fellow eye is affected strongly by characteristics of its central macula and by systemic hypertension. These factors should be considered when counseling patients with unilateral neovascular age-related macular degeneration and when targeting patients for preventive interventions.