Faculty Bibliography

BACKGROUND AND OBJECTIVES: Mutations of the peripherin/RDS gene have been reported in autosomal dominant retinitis pigmentosa, pattern macular dystrophy, and retinitis punctata albescens. We report herein the occurrence of three separate phenotypes within a single family with a novel 3-base pair deletion of codon 153 or 154 of the peripherin/RDS gene. DESIGN: Case reports with clinical features, fluorescein angiography, kinetic perimetry, electrophysiological studies, and molecular genetics. SETTING: University medical centers. PATIENTS: A 75-year-old woman, her two daughters (aged 44 and 50 years), and her 49-year-old son were screened for peripherin/RDS mutations because of the presence of multiple phenotypes within the same family. RESULTS: The mother presented at age 63 years with a profoundly abnormal electroretinogram (ERG) and adult-onset retinitis pigmentosa that progressed dramatically over 12 years, with marked loss of peripheral visual field. One daughter developed pattern macular dystrophy at age 31 years. At age 44 years, her ERG was moderately abnormal but her clinical disease was limited to the macula. Another daughter presented at age 42 years with macular degeneration and over 10 years developed the clinical picture of fundus flavimaculatus. Her peripheral visual field was preserved but her ERG was moderately abnormal. The son had onset of macular degeneration at age 44 years. Pericentral scotomas were present and the ERG was markedly abnormal. Fluorescein angiography revealed punctate pigment epithelial transmission defects. CONCLUSIONS: A 3-base pair deletion of codon 153 or 154 of the peripherin/RDS gene can produce clinically disparate phenotypes even within the same family

Previous studies have shown that S-cone pathway sensitivity is selectively decreased in the early stages of diabetic retinopathy. In the present study, rod system sensitivity was evaluated in a group of diabetic patients using psychophysical techniques. The course of dark adaptation was first determined, then absolute thresholds were measured in the horizontal and vertical meridians. For all patients, although the recovery of the initial portions of rod dark adaptation were normal, absolute thresholds were increased in both the horizontal and vertical meridians. The findings provide evidence that patients with early diabetic retinopathy show a generalized dysfunction of the rod system

PURPOSE. To study the effects of acetazolamide on central and peripheral visual function in patients with retinitis pigmentosa (RP) who showed no evidence of macular edema. METHODS. Thirteen patients with retinitis pigmentosa participated in a preliminary study. Measures of central and peripheral visual function were obtained before and after an 8 wk period on acetazolamide. An additional 10 patients participated in a cross-over study. They were placed on a placebo for an 8 wk period, then on acetazolamide for a second 8 wk period. RESULTS. None of the patients in the preliminary study showed significant changes in visual acuity, color vision, foveal cone pathway sensitivities, focal electroretinogram (ERG) amplitudes, or in any ERG parameter. Three patients, however, showed significant changes in visual field area and in dark-adapted thresholds. None of the patients in the cross-over study showed significant increases in visual field area. CONCLUSIONS. Given the results and the reports of side-effects, it is difficult to justify using acetazolamide to improve retinal function in RP patients who show no evidence of cystoid macular edema

Previous studies of early diabetic retinopathy have shown that oscillatory potential (OP) amplitudes are reduced in many diabetic patients. OP amplitude is believed to be a more sensitive indicator of the development of future retinopathy than b-wave amplitude of the scotopic electroretinogram (ERG). Because OPs measured to a bright white flash reflect both rod and cone system activity, it is important to compare OP amplitudes to photopic ERG measures as well as scotopic measures in early diabetic retinopathy. In this study, OPs and ERG responses were measured under photopic and scotopic conditions in a group of diabetic patients. Although OPs were reduced in amplitude in the diabetic group, several other parameters of the scotopic and photopic b-waves were impaired. The results indicate that b-wave activity may indicate retinal changes in early diabetic retinopathy in the same manner as the OPs