Estimated Rates of Progression to Advanced AMD and Vision Loss by Baseline Maculopathy Status: Results from the Age–Related Eye Disease Study

Abstract

Abstract: : Purpose: Provide estimated rates of progression to advanced AMD and vision loss to aid in planning future clinical trials of AMD. Methods: 4,757 participants enrolled in AREDS were classified by a reading center based on stereo color fundus photographs taken at enrollment, two years following enrollment and annually thereafter. Development of advanced AMD was defined as geographic atrophy involving the center of the macula or neovascular AMD (photographic evidence of subretinal hemorrhage or fibrosis or detachment of the sensory retina or retinal pigment epithelium; or application of photocoagulation). Participants were randomized in a factorial design to treatment with placebo, antioxidants, zinc with copper or a combination of antioxidants and zinc. Repeated measures logistic regression was used to estimate the probability of progression to advanced AMD over time for various maculopathy status characteristics. Results: 4,757 participants were enrolled in AREDS between 1993 and 2001. Median follow–up in the clinical trial was 6.5 years. The probability of progression to advanced AMD for participants with various maculopathy status baseline characteristics (including extensive small drusen, large drusen in one eye, large drusen in both eyes, advanced AMD in one eye or vision loss due to advanced AMD in one eye) by gender, age, and randomized treatment will be provided as a resource for sample size determination for future clinical trials. For example, the estimated 5–year probability of progression to advanced AMD in the fellow eye of persons with one eye already with advanced AMD is shown below.  

Conclusion: Event rates observed in AREDS may be useful in identifying populations at risk and expected event rates for future studies of therapies targeted at reducing the risk of advanced AMD development and vision loss.

Keywords: age–related macular degeneration • clinical (human) or epidemiologic studies: prevalence/incidence