Recovery of vision after treatment of hemodialysis related bilateral optic nerve ischemia.

PURPOSE: We present the case of a patient who lost light perception in both eyes after hemodialysis and subsequently recovered vision after treatment with erythropoietin and intravenous steroids. OBSERVATIONS: Our patient reported loss of light perception in both eyes (NLP) 2 hours after hemodialysis. Examination confirmed NLP vision, chronic retinal vascular changes, and no acute changes in optic nerve appearance. A presumptive diagnosis of posterior optic neuropathy was made. The patient was treated with erythropoietin and intravenous steroids according to the protocol of Nikkah. Over a period of 14 hours, he recovered vision to his baseline. CONCLUSIONS AND IMPORTANCE: Bilateral loss of light perception is a rare complication of hemodialysis. The presumed mechanism is posterior ischemic optic neuropathy. Prompt treatment with erythropoietin and intravenous steroids should be considered in similar situations that result in Posterior ischemic optic neuropathy (PION) related to procedure-based hypotension.

A new locus for dominant drusen and macular degeneration maps to chromosome 6q14.

PURPOSE: To report the localization of a gene causing drusen and macular degeneration in a previously undescribed North American family. METHODS: Genetic mapping studies were performed using linkage analysis in a single family with drusen and atrophic macular degeneration. RESULTS: The clinical manifestations in this family ranged from fine macular drusen in asymptomatic middle-aged individuals to atrophic macular lesions in two children and two elderly patients. We mapped the gene to chromosome 6q14 between markers D6S2258 and D6S1644. CONCLUSIONS: In a family with autosomal dominant drusen and atrophic macular degeneration, the gene maps to a 3.2-cM region on chromosome 6q14. This locus appears to be distinct from, but adjacent to, the loci for cone-rod dystrophy 7 (CORD7) and North Carolina macular dystrophy (MCDR1). Future identification of the gene responsible for the disease in this family will provide a better understanding of macular degeneration.

Clinical spectrum of chromosome 6-linked autosomal dominant drusen and macular degeneration.

PURPOSE: To describe the clinical phenotype and the intrafamilial variation in retinal findings in a North American family with an autosomal dominant drusen disorder that maps to chromosome 6q14. METHODS: Ophthalmic examinations were carried out on participating family members. Fundus photographs were obtained whenever possible. Electroretinography was performed on the proband and her father. Blood was drawn for DNA analysis. RESULTS: Twelve family members had drusen and/or atrophic macular degeneration. The disease in asymptomatic young adults is characterized by fine drusen that are most conspicuous in the macula. The proband presented at 3 years of age with atrophic maculopathy and drusen. Her cousin was found to have atrophic macular lesions and drusen in the first year of life. Two older affected individuals have reduced vision from cicatricial and atrophic macular changes. The gene for the disease was mapped to chromosome 6q14 and appears to be adjacent to but distinct from the locus for North Carolina macular dystrophy. CONCLUSIONS: There is extreme variability in the clinical expression of this dominant form of drusen and macular degeneration. Most young adults have fine macular drusen and good vision. Affected infants and children may have congenital atrophic maculopathy and drusen. There is historical evidence of progression of the disease in late adulthood with moderate visual loss.

Linkage analysis of X-linked cone-rod dystrophy: localization to Xp11.4 and definition of a locus distinct from RP2 and RP3.

Progressive X-linked cone-rod dystrophy (COD1) is a retinal disease affecting primarily the cone photoreceptors. The COD1 locus originally was localized, by the study of three independent families, to a region between Xp11.3 and Xp21.1, encompassing the retinitis pigmentosa (RP) 3 locus. We have refined the COD1 locus to a limited region of Xp11.4, using two families reported elsewhere and a new extended family. Genotype analysis was performed by use of eight microsatellite markers (tel-M6CA, DXS1068, DXS1058, DXS993, DXS228, DXS1201, DXS1003, and DXS1055-cent), spanning a distance of 20 cM. Nine-point linkage analysis, by use of the VITESSE program for X-linked disorders, established a maximum LOD score (17.5) between markers DXS1058 and DXS993, spanning 4.0 cM. Two additional markers, DXS977 and DXS556, which map between DXS1058 and DXS993, were used to further narrow the critical region. The RP3 gene, RPGR, was excluded on the basis of two obligate recombinants, observed in two independent families. In a third family, linkage analysis did not exclude the RPGR locus. The entire coding region of the RPGR gene from two affected males from family 2 was sequenced and was found to be normal. Haplotype analysis of two family branches, containing three obligate recombinants, two affected and one unaffected, defined the COD1 locus as distal to DXS993 and proximal to DXS556, a distance of approximately 1.0 Mb. This study excludes COD1 as an allelic variant of RP3 and establishes a novel locus that is sufficiently defined for positional cloning.

Dominant inheritance of optic pits.

PURPOSE: To report the familial occurrence of optic pits and to screen the candidate PAX2 gene for mutations in this family. METHODS: Clinical family study. Standard mutation analysis of the PAX2 exons. RESULTS: Unilateral optic pits were present in three generations of one family and were inherited in an autosomal dominant fashion. No mutations in the PAX2 gene, responsible for the renal-optic coloboma syndrome, were found. CONCLUSION: Unilateral optic pits may be inherited in an autosomal dominant fashion and not in association with mutation in the PAX2 gene.