title: The enhanced S cone syndrome: an analysis of receptoral and post-receptoral changes.
abstract: The purpose of the study was to test the hypothesis that the retinae of patients with enhanced S cone syndrome (ESCS) have more S cones than the normal retina and these cones have replaced some of the L and M cones. Standard and spectral full-field electroretinograms, measurements of L, M, and S cone system sensitivities and S cone acuity were obtained from three patients with ESCS. The results were qualitatively consistent with the presence of more S cones and more S cone ganglion cells. To test this hypothesis further, a model of the receptoral and post-receptoral components of the S cone system was used in conjunction with psychophysical measurements of S cone system sensitivity under flashed and steady-state adaptation conditions. Within the context of the model, the data were consistent with an increase in the number of S cones and S - (L + M) ganglion cells and with a decrease in the total L + M cone input to each S - (L + M) ganglion cell.
authors.affiliation: Department of Opthalmology, NYU Medical Center, NY 10016, USA.
authors.forename: V C
authors.initials: VC
authors.lastname: Greenstein
authors.forename: Q
authors.initials: Q
authors.lastname: Zaidi
authors.forename: D C
authors.initials: DC
authors.lastname: Hood
authors.forename: B
authors.initials: B
authors.lastname: Spehar
authors.forename: A V
authors.initials: AV
authors.lastname: Cideciyan
authors.forename: S G
authors.initials: SG
authors.lastname: Jacobson
mesh_terms: D000221:Adaptation, Ocular; D000293:Adolescent; D000328:Adult; D004596:Electroretinography; D005260:Female; D006801:Humans; D008297:Male; D011601:Psychophysics; D017949:Retinal Cone Photoreceptor Cells / Q000503:physiopathology*; D012162:Retinal Degeneration / Q000503:physiopathology*; D012684:Sensory Thresholds; D014792:Visual Acuity; D058609:Visual Field Tests