X-linked recessive retinitis pigmentosa. Clinical characteristics of carriers.

We evaluated 46 carriers of X-linked recessive retinitis pigmentosa for the prevalence of fundus changes, refractive errors, central visual impairment, and electroretinographic abnormalities. Of the 46 carriers, 40 (87%) could be identified by characteristic fundus changes and 37 (86%) of 43 by reductions in electroretinographic amplitude. Interestingly, 36 carriers (78%) had a refractive cylindrical correction of +1.50 diopters (D) or greater in at least one eye, while 25 (54%) had a best corrected visual acuity of 20/30 or less in at least one eye. Fundus examination coupled with an electroretinographic recording was diagnostic of the carrier state in virtually all 46 patients. The presence of a refractive cylinder of +1.50 D or greater should appreciably increase the index of suspicion when assessing the possibility of the carrier state in X-linked retinitis pigmentosa.