Photofield mapping is a useful method for classifying subretinal neovascularization based on its area and location. Careful central field mapping is performed to delineate scotomata during evaluation of patients with subretinal new vessels. A photofield map is then constructed by projecting 35 mm fundus photographs and angiograms onto an appropriately-oriented central visual field map. The composite map (photofield) documents the location and relationship of scotomata, subretinal neovascularization, foveal avascular zone, and retinal blood vessels. The areas of subretinal neovascularization and scotomata are measured in square millimeters with a planimeter. The distance between their closest edge and the center of the foveal avascular zone is measured in millimeters. This method permits quantitative comparison of results with different photocoagulation protocols and instrumentation. Such comparative analysis may help improve the technique and instrumentation used in laser photocoagulation of subretinal neovascularization.