[Carotenoid retinopathy. I. Morphologic and functional findings].

Thirty patients who had undergone long-term treatment with carotenoids (max. 14 years and 336 g of carotenoids) were examined. Ophthalmoscopy revealed retinal crystals in 20 patients. The retinal crystals were usually located around the macula, forming a ring, and in one case they were even found in the macula itself. No deterioration of visual acuity or visual field defects were found, but there was a markedly dose-dependent prolongation of the duration of dark adaptation.