Risk factors for radiation maculopathy and papillopathy after intraocular irradiation

Purpose: To evaluate rates of occurrence and risk factors for radiation maculopathy and radiation papillopathy in patients with choroidal melanoma at high risk for these complications, Design: Cohort study, Participants: A total of 558 patients treated with proton irradiation for choroidal melanoma between 1986 and 1996 with small to moderate sized tumors (less than 5 mm in height and 15 mm in diameter) located within 4 disc diameters of the macula or optic nerve and with a median ocular follow-up of 4 years. Methods: Annual and cumulative rates of each endpoint were estimated using life table approaches. Prognostic factors were evaluated using the Cox proportional hazards regression. Main Outcome Measures: Radiation maculopathy, radiation papillopathy, and vision loss to worse than 20/100. Results: Cumulative 5-year rates for radiation maculopathy, radiation papillopathy, and vision loss were 64%, 35%, and 68%, respectively. Complication rates rose as a function of radiation exposure to the macula (P for trend = 0.04) or optic disc (P for trend < 0.001), although dose-response patterns were nonlinear. History of diabetes was a significant risk factor for maculopathy (P < 0.001) and optic neuropathy (P = 0.009). Conclusions: The onset of radiation vasculopathy is determined primarily by the degree of irradiation exposure to the macula and optic disc. Risk may be enhanced among those with underlying vascular disorders.