retinitis pigmentosa [L, rete, net; Gk, itis, inflammation; L, pigmentum, paint] , a group of diseases, often hereditary, characterized by bilateral primary degeneration of the retina beginning in childhood and progressing to blindness by middle age. Clinical signs include night blindness, reduced visual fields, depigmentation of the retinal pigment epithelium, and macular degeneration. Length of time to legal blindness varies widely.
