دورية أكاديمية
Rod and Cone Function in the Nougaret Form of Stationary Night Blindness.
العنوان: | Rod and Cone Function in the Nougaret Form of Stationary Night Blindness. |
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المؤلفون: | Sandberg, Michael A., Pawlyk, Basil S., Dan, Jeffrey, Arnaud, Bernard, Dryja, Thaddeus P., Berson, Eliot L. |
المصدر: | Archives of Ophthalmology; Jul98, Vol. 116 Issue 7, p867, 6p |
مصطلحات موضوعية: | EYE physiology, SENSORY receptors, BLINDNESS |
مستخلص: | Background: Recently, a mutation (Gly38Asp) was identified in the α subunit of rod transducin in members of the Nougaret pedigree affected with dominantly inherited stationary night blindness. Objective: To evaluate retinal function in patients with the Gly38Asp gene defect. Design: Ocular examinations, including specialized measures of rod and cone function. Setting: A clinical research facility in Boston, Mass. Patients: A father (aged 48 years) and son (aged 25 years) with the Gly38Asp mutation. Main Outcome Measures: Psychophysical thresholds to white and narrowband lights and full-field dectroretinographic (ERG) responses. Results: Both patients showed dark-adapted thresholds to white light that were elevated approximately 2 log-units across the retina. Spectral sensitivity testing revealed thresholds that seemed to be governed mostly by rods. Although both patients' dark-adapted ERG responses to a dim blue flash were nondetectable, their darkadapted ERGs to a white flash showed an a-wave with cone and rod components and a b-wave amplitude larger than what could have been generated by cone function alone. Rod ERGs to bright blue flashes had subnormal, but detectable, amplitudes that seemed to result from a profound reduction in sensitivity. The patients also showed loss of a cone subcomponent in the darkadapted response to a red flash. The abnormal darkadapted ERG responses of the patients could be simulated in the ERG responses of normal subjects tested with blue, white, and red flashes presented in the presence of a mesopic background. Conclusions: Although the Nougaret form of stationary night blindness has been cited as a prototype of absent rod function with normal cone function, our findings, based on the genealogically and genotypically documented descendants of Jean Nougaret, show that rod function is present, although subnormal, and that there is slight impairment of cone function. The data also suggest that these abnormalities can be... [ABSTRACT FROM AUTHOR] |
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قاعدة البيانات: | Complementary Index |
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