Early Macular Involvement in Non-syndromic Retinitis Pigmentosa

Abstract

Retinitis pigmentosa (RP) is the most common inherited retinal disease (IRD), with a worldwide prevalence of about 1:4000. Functionally, RP is a rod-cone dystrophy (RCD), where rod photoreceptors are affected earlier and more severely than cone photoreceptors. As a consequence, RP typically manifests with night blindness beginning in adolescence followed by concentric constriction of visual field, while central visual loss usually occurs later in life. The molecular bases of this disorder, however, are highly heterogeneous, with over 100 genes implicated, and in some RP subtypes macular manifestations occur relatively early in the disease course. The subsequent rapid decline in visual acuity in such patients blurs the line between RP and other IRDs, namely cone-rod dystrophies (CORDs), and increases the difficulty in narrowing down the differential diagnosis. This chapter aims to review the features of non-syndromic RP caused by mutations in genes that have been commonly associated with early macular involvement and to provide an updated overview on recent preclinical or clinical studies addressing these rare diseases.