Weber U, Goerz G
Klin Monbl Augenheilkd. 1986 Jan;188(1):20-2. doi: 10.1055/s-2008-1050566.
Twenty-five patients (erythropoietic protoporphyria 23, polymorphous light eruption 1, "cosmetics" 1) were re-examined 2-10 months after therapy with beta-carotene and canthaxanthine was discontinued. Dark adaptation and ERG parameters had normalized, whereas crystalline retinopathy and pigment epithelial defects showed no signs of reversibility.