Lesion morphology in age-related macular degeneration and its therapeutic significance

Objectives: To quantify and categorize the lesions of neovascular age-related macular degeneration on the basis of fluorescein angiographic morphology. Methods: We retrospectively reviewed 3580 consecutive cases of neovascular age-related macular degeneration. The lesions were graded in terms of the location, size, and composition and categorized according to the lesion components. Results: A comprehensive schema for lesion description and categorization is presented. There were 2642 subfoveal (73.8%), 658 juxtafoveal (18.4%), and 276 extrafoveal (7.7%) lesions. After disciform lesions were excluded, 1337 subfoveal (72.3%), 580 juxtafoveal (88.1%), and 242 extrafoveal lesions (87.7%) consisted of at least 50% choroidal neovascularization, most of which included a classic or an occult component but not both. Subfoveal lesions (mean size, 2.82 Macular Photocoagulation Study disc areas) were significantly larger than juxtafoveal (mean size, 0.89 Macular Photocoagulation Study disc areas) or extrafoveal lesions (mean size, 1.04 Macular Photocoagulation Study disc areas) (Kruskal Wallis, P < .001), but overall the lesions were substantially smaller than those found in the major trials. It is estimated that photodynamic therapy or photocoagulation may be offered to one half to two thirds of all patients with nondisciform neovascular age-related macular degeneration. Conclusion: The smaller lesion size and low proportion of mixed choroidal neovascularization lesions suggest that treatment benefit and eligibility may be greater in the clinical setting than previously thought.