Calcium oxalate retinopathy associated with generalized oxalosis: x-ray diffraction and electron microscopic studies of crystal deposits.

This reports crystallographic and light and electron microscopic findings in a previously undescribed entity: calcium oxalate retinopathy associated with generalized oxalosis. The affected patient was a 66-year-old vohite male with a previous history of mild hypertensive renal disease who had undergone prolonged abdominal surgery under methoxyfiurane (MOF; Penthrane) anesthesia. He subsequently developed acute irreversible renal failure caused by renal oxalosis as shown by renal biopsy. He was maintained on renal dialysis and shortly before his death three years later he was noted to have changes in the fundus oculi suggestive of the flecked retina syndrome. Widespread oxalosis was found at autopsy. Light and electron microscopy revealed particularly heavy depositions within the retinal pigment epithelium (RPE). Positive identification of the deposits as the monohydrate form of calcium oxalate was obtained by x-ray diffraction investigations.