RDH8 and retinal degeneration: A detailed analysis of the age-dependent reduction of photoreceptor nuclei numbers of the three different Stargardt mouse strains revealed similar retinal degeneration courses for both albino Abca4−∕− and Abca4−∕−.Rdh8−∕− mice (Fig. 1C) as compared to the pigmented Abca4−∕− mice for which it is known that they do not present signs of retinal degeneration (Charbel Issa et al., 2013; Weng et al., 1999).