USH2A and Leber congenital amaurosis: Splice-switching AONs have already made a mark in the field of therapies for IRD with ongoing clinical trials for Leber congenital amaurosis due to a deep-intronic mutation in CEP290 c.2991+1655A>G [16] and retinitis pigmentosa caused by coding variants in exon 13 of USH2A [42].