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.