Delayed visual loss due to radiation retinopathy.

Radiation retinopathy remains a devastating cause of visual morbidity in patients undergoing radiation for globe, orbit, and head and neck malignancies. A 65-year-old female was admitted with the complaint of low vision in the right eye for two months. Best corrected visual acuity was 20/32 in the right eye and 20/25 in the left eye. Slit lamp examination was normal in both eyes. Fundoscopic examination revealed perifoveolar hard exudates, paramacular microhemorrhages, telangiectasias, and macular degeneration in both eyes. Fundus florescein angiography showed enlargement of the foveal avascular zone, perifoveal capillary telangiectasia, and widespread venous beading bilaterally. Optical coherence tomography revealed bilateral cystoid macular edema. The prediagnosis of diabetic retinopathy was not confirmed because of the absence of diabetes mellitus after endocrinologic evaluation. Detailed medical history explored external beam radiotherapy to the head and neck region for nasopharyngeal cancer 10 years ago. The ultimate diagnosis was radiation retinopathy.