As for the pre-ganglionic elements macular dysfunction observed in C-FRDA, in an animal mouse model of FRDA, signs of outer retinal degeneration with retinal pigmented epithelium thinning and photoreceptor loss have been reported, suggesting that low levels of frataxin correspond to an insufficient antioxidant capability to sustain photoreceptor vitality [35]. This evidence concerns the gene FXN and Friedreich ataxia.