Retinopathy after low-dose retinal irradiation.

A 28-year-old man, after subtotal resection of a Grade I-II frontal lobe astrocytoma, received 5600 cGy of radiotherapy in 200 cGy fractions to residual intracranial tumour. One year later he presented with severe bilateral retinopathy which, in appearance was consistent with retinopathy from irradiation. Total irradiation received by the retina of each eye (< 50 to 1500 cGy) was far less than the dose which commonly produces radiation retinopathy. Also, the pattern of retinopathy did not reflect the distribution of radiation received by the eye. Alternative causes for the retinopathy were sought but not found. Proliferative retinopathy occurred in each eye and one eye developed a dense vitreous haemorrhage. Argon laser pan-retinal photocoagulation controlled the neovascularisation in the other eye. This patient has developed severe retinal ischaemia after a low dose of retinal irradiation.