Mutations in the retinoid isomerase (RPE65) or lecithin-retinol acyltransferase (LRAT) genes underlie Leber congenital amaurosis (den Hollander et al., 2008). LRAT is involved in 11-cis retinal recycling in the retinal pigment epithelium through mediating the esterification of all-trans retinol to all-trans retinyl esters, which are the substrates for RPE65. Homozygous Lrat knockout mice that were subcutaneously administered TUDCA every 3 days from 1 to 4 weeks after birth had about a three-fold increase in cone density in the ventral and central retina and increased ER-associated protein degradation (Zhang et al., 2012; Fu and Zhang, 2014). Twice per week subcutaneous injections of TUDCA also preserved ERG b-waves and the outer nuclear layer of the retina in Bardet-Biedl syndrome type 1 mice (Bbs1M390R/M390R), another model for retinal degeneration (Drack et al., 2012).