Visual Prognosis in -Associated Retinitis Pigmentosa Is Worse for Patients with Usher Syndrome Type IIa Than for Those with Nonsyndromic Retinitis Pigmentosa

USH2A mutations are an important cause of retinitis pigmentosa (RP) with or without congenital sensorineural hearing impairment. We studied genotype–phenotype correlations and compared visual prognosis in Usher syndrome type IIa and nonsyndromic RP.