title: Two-color pupillometry in enhanced S-cone syndrome caused by NR2E3 mutations.
abstract: The purpose of this study was to evaluate pupillary light reflexes (PLRs) mediated by rod, cone, and intrinsically photosensitive retinal ganglion cell pathways as indices of outer- and inner-retinal function in patients who have enhanced S-cone syndrome (ESCS) due to NR2E3 mutations.
  
  
  
  Four patients with ESCS (ages 16-23 years) participated in the study. Subjects were tested with long- and short-wavelength single-flash full-field ERG stimuli under light-adapted conditions. They were also tested with an established pupillometry protocol involving 1-s duration, long- and short-wavelength stimuli under dark- and light-adapted conditions. The PLR was measured as a function of stimulus luminance. Transient PLRs were measured under all conditions, and sustained PLRs were measured under the highest luminance dark-adapted condition.
  
  
  
  Two-color light-adapted full-field ERGs demonstrated larger amplitude responses for short-wavelength stimuli relative to long-wavelength stimuli of the same photopic luminance, with three of four ESCS patients having super-normal a-wave amplitudes to the short-wavelength stimulus. b/a wave ratios were reduced in all four cases. Transient PLRs elicited by low-luminance stimuli under dark-adapted conditions (rod-mediated) were unrecordable, whereas the sustained PLRs elicited by high-luminance stimuli (melanopsin-mediated) were normal. Cone-mediated PLRs were recordable for all four patients, but generally lower than normal in amplitude. However, the cone-mediated PLR was larger for the short-wavelength stimulus compared to the photopically matched long-wavelength stimulus at high luminances, a pattern that was not observed for control subjects. None of the PLR conditions demonstrated "super-normal" responses.
  
  
  
  ESCS patients appear to have generally well-preserved cone- and melanopsin-mediated PLRs, indicating intact inner-retinal function. Two-color pupillometry demonstrates greater sensitivity to short-wavelength light under higher-luminance conditions and could complement the ERG as a tool for evaluating retinal function in ESCS.
authors.affiliation: The Pangere Center for Hereditary Retinal Diseases, The Chicago Lighthouse, 1850 West Roosevelt Rd., Chicago, IL, 60608, USA.
authors.forename: Frederick T
authors.initials: FT
authors.lastname: Collison
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago College of Medicine, 1905 West Taylor St., Chicago, IL, 60612, USA.
authors.forename: Jason C
authors.initials: JC
authors.lastname: Park
authors.affiliation: The Pangere Center for Hereditary Retinal Diseases, The Chicago Lighthouse, 1850 West Roosevelt Rd., Chicago, IL, 60608, USA. gerafish@uic.edu.|Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago College of Medicine, 1905 West Taylor St., Chicago, IL, 60612, USA. gerafish@uic.edu.
authors.forename: Gerald A
authors.initials: GA
authors.lastname: Fishman
authors.affiliation: Stephen A. Wynn Institute for Vision Research, Department of Ophthalmology and Visual Sciences, Carver College of Medicine, University of Iowa, 375 Newton Rd. 4111 MERF, Iowa City, IA, 52242, USA.
authors.forename: Edwin M
authors.initials: EM
authors.lastname: Stone
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago College of Medicine, 1905 West Taylor St., Chicago, IL, 60612, USA.
authors.forename: J Jason
authors.initials: JJ
authors.lastname: McAnany
mesh_terms: D000293:Adolescent; D000328:Adult; D055253:Color Vision / Q000502:physiology*; D003623:Dark Adaptation / Q000502:physiology; D004596:Electroretinography / Q000379:methods; D015785:Eye Diseases, Hereditary / Q000235:genetics / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008027:Light; D008297:Male; D009154:Mutation; D057093:Orphan Nuclear Receptors / Q000235:genetics*; D010775:Photic Stimulation; D012025:Reflex, Pupillary / Q000502:physiology* / Q000528:radiation effects; D012160:Retina / Q000503:physiopathology*; D017949:Retinal Cone Photoreceptor Cells / Q000502:physiology; D012162:Retinal Degeneration / Q000235:genetics / Q000503:physiopathology*; D012165:Retinal Ganglion Cells / Q000502:physiology; D017948:Retinal Rod Photoreceptor Cells / Q000502:physiology; D014786:Vision Disorders / Q000235:genetics / Q000503:physiopathology*; D055815:Young Adult
chemical_list: C403073:NR2E3 protein, human; D057093:Orphan Nuclear Receptors
keywords: Enhanced S-cone syndrome; Full-field electroretinogram; NR2E3; Pupillary light reflex; Pupillometry