Radiotherapy of exudative age-related macular degeneration; a clinical andpathologic study

Background: Radiotherapy has recently been employed to treat patients with exudative macular degeneration in order to prevent severe visual loss. Radi otherapy affects the evolution of exudative macular degeneration directly b y endothelial toxicity, leading to capillary closure, and/or indirectly thr ough its attenuating effects on the inflammatory response, mediated by macr ophages and other inflammatory cells. Methods: In this study we describe th e histopathologic findings in a patient with exudative age-related macular degeneration (AMD) in both eyes whose right eye was treated with radiothera py (5 times 2 Gy) 3 years before he died. The eyes were enucleated post mor tem and investigated by light microscopy. Additionally, immunohistochemical investigation with antibodies against CD34 and CD68 was performed to ident ify patent endothelial cells and macrophages. Results: Both eyes showed neo vascular AMD consisting of mixed fibrocellular and fibrovascular membranes. Capillaries in both the choriocapillaris and the neovascular membrane were patent in both eyes. Macrophages were present in the choroidal neovascular ization of both eyes. Neither preexistent choroidal, intraretinal, nor neov ascular vessels showed increased wall thickness as sign of radiation damage . Conclusion: No radiation-related histopathologic effect could be demonstr ated 3 years after radiation therapy in this patient with AMD.