Absence of crystalline retinopathy after long-term therapy with beta-carotene.

The retinas of twenty-six patients with protoporphyria who had received treatment with beta-carotene for periods ranging from 1 to 10 years were examined for the presence of yellow crystalline deposits, similar to those recently reported in and around the maculae of individuals ingesting the related carotenoid compound canthaxanthin. No crystalline deposits were observed in any of our patients.