Radiation maculopathy after proton beam irradiation for choroidal melanoma

Radiation maculopathy is a microangiopathy of the retina, which is often observed after irradiation of the eye. To quantitatively determine the frequency of anatomic and functional features of this condition, the authors reviewed a large series of patients with choroidal melanomas who were treated by proton beam irradiation.

Color photographs and/or fluorescein angiograms of 218 patients with paramacular choroidal melanomas were graded by two independent masked readers to determine the frequency of the various lesions of radiation maculopathy.

Overall, 194 (89%) of the 218 patients in this study developed some degree of radiation maculopathy. The earliest and most common finding was macular edema, which was observed in 87% of patients, overall, by the end of year 3. Microvascular changes (microaneurysms and/or telangiectasia), intraretinal hemorrhages, and capillary nonperfusion were noted in 76%, 70%, and 64% of eyes, respectively, by the end of postirradiation year 3. Visual acuity was retained at 20/200 or better in 90% of eyes 1 year after irradiation and in 67% of eyes 3 years after treatment.

Radiation maculopathy is common after proton beam irradiation of paramacular choroidal melanomas. However, ambulatory vision is preserved in many eyes.