Clinicopathologic studies of age-related macular degeneration with classicsubfoveal choroidal neovascularization treated with photodynamic therapy

Background: Photodynamic therapy (PDT) is a relatively new modality that is currently under clinical and experimental evaluation for treatment of subf oveal choroidal neovascularization (CNV). The authors report the case of an 82-year-old woman who underwent verte-porfin-mediated PDT for classic subf oveal CNV. Fluorescein angiography performed 2 weeks after treatment disclo sed reduction of the initial area of neovascularization and leakage by appr oximately 60%. Three weeks after PDT, however, the area of leakage was almo st the same size as that before treatment. The patient underwent submacular membranectomy almost 4 weeks after treatment. The authors describe the ult rastructural vascular changes after PDT and a clinicopathologic study of cl assic CNV. Methods: The submacular membrane was studied by light and electron microsco py and immunohistochemical techniques. Results: Ultrastructural examination of the peripheral vessels showed evide nce of endothelial cell degeneration with platelet aggregation and thrombus formation. Occasional occluded vessels were surrounded by macrophages, a p henomenon previously reported to describe the process of resorption of such blood vessels. The vessels in the center of the membrane were unremarkable . Conclusion: Photodynamic therapy causes endothelial cell damage, thrombus f ormation, and vascular occlusion of classic CNV in age-related macular dege neration.