Retinopathy after low dose irradiation for an intracranial tumor of the frontal lobe. A case report

A 32-year-old man underwent an operation for an oligodendroglioma of the left frontal lobe. Post-operatively he was irradiated to a target dose of 54 Gy. One year later he developed bilateral retinopathy quite similar to diabetic retinopathy. There were no clinical or biochemical signs of diabetes or hematological disease. The calculated maximum dose to the retina was 11 Gy. This is to our knowledge the lowest retinal dose of ionizing radiation reported to produce retinopathy.