Early preclinical trials, such as the successful rescue of retinal degeneration in mouse models of retinitis pigmentosa (RP) by Bennett et al. in 1996 and the restoration of vision in canine models of RPE65 Leber congenital amaurosis (LCA) proved the efficacy of retinal gene therapy [9,10]. Here, RPE65 is linked to Leber congenital amaurosis.