A 24-year-old female complained of a decrease in right and left visual acuity (0.1/0.2). The patient had a mottled retina but no pigments (1, 2), extinguished scotopic electroretinographic response by impaired rod function, constricted visual fields (3), and bad central acuity due to cystoid maculopathy (4). There were none of the pigmentary changes usually associated with retinitis pigmentosa. Therefore the case is most probably one of bilateral retinitis pigmentosa sine pigmento.
Retinitis pigmentosa RP has a prevalence of 1/4000. RP is a set of hereditary retinal dystrophies characterized by pigment deposits in fundus and progressive death of photoreceptors. RP is always associated with the alteration of retinal pigment epithelium. The prevalence of cystoid macula edema CME, defined by cysts visible on OCT, is about 50%. Genetic heterogeneity of the typical nonsyndromic form (rod cone dystrophy) is extensive: 11 genes and one locus for autosomal dominant RP, 17 genes and five loci for autosomal recessive RP, and two genes and two loci for X-linked RP.
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