GUCY2D and Leber congenital amaurosis: While early reports indicated retinal degeneration was associated with this form of LCA (Milam et al., 2003; Porto et al., 2003), later studies revealed preservation of retinal laminar architecture in LCA1 patients (Simonelli et al., 2007; Pasadhika et al., 2010; Jacobson et al., 2013).