title: X-linked progressive cone dystrophy. Clinical characteristics of affected males and female carriers.
abstract: The authors evaluated nine affected males and six female carriers from a four-generation family with X-linked cone dystrophy. As the affected males grew older, visual acuity deteriorated, central scotomas deepened, and macular changes became more prominent. There was granularity of the macula in younger individuals and bull's eye lesions and central geographic atrophy of the retinal pigment epithelium (RPE) in the older subjects. The retinas of some affected males had a bronze-green tapetal-like sheen. Color vision was impaired in all affected males and resembled an acquired type II defect (Verriest classification). One younger subject had paradoxical pupillary constriction to darkness. Visual-evoked potential (VEP) latencies were prolonged in some affected males, suggesting that photoreceptor degeneration caused transsynaptic degeneration of ganglion cells. All female carriers had visual acuities of 20/30 or better, but some showed mild ophthalmoscopic changes and abnormalities of color vision, electroretinograms (ERGs), and VEPs.
authors.affiliation: Department of Neurology, Marshfield Clinic, WI 54449.
authors.forename: D M
authors.initials: DM
authors.lastname: Jacobson
authors.forename: H S
authors.initials: HS
authors.lastname: Thompson
authors.forename: J A
authors.initials: JA
authors.lastname: Bartley
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D003118:Color Perception; D005074:Evoked Potentials, Visual; D005260:Female; D005451:Fluorescein Angiography; D008040:Genetic Linkage; D006801:Humans; D008297:Male; D008875:Middle Aged; D010375:Pedigree; D010786:Photoreceptor Cells / Q000002:abnormalities*; D010857:Pigment Epithelium of Eye / Q000473:pathology; D012162:Retinal Degeneration / Q000235:genetics*; D012607:Scotoma / Q000150:complications; D012737:Sex Factors; D014792:Visual Acuity; D058609:Visual Field Tests; D014794:Visual Fields; D014960:X Chromosome / Q000002:abnormalities*