title: Abnormal 8-Hz flicker electroretinograms in carriers of X-linked retinoschisis.
abstract: To evaluate rod-isolated, cone-isolated, and combined rod and cone flicker electroretinograms (ERGs) as a possible means to identify electrophysiological abnormalities in carriers of X-linked retinoschisis (XLRS).
  
  
  
  Full-field ERGs were recorded from six carriers of XLRS (aged 34-66 years) and eight normally sighted subjects (aged 27-59 years) under rod-isolated (ERGR), cone-isolated (ERGC), and combined rod and cone (ERGR+C) conditions. ERGs were obtained using a four-primary LED-based ganzfeld photostimulator and standard recording techniques. The four primaries were modulated sinusoidally in phase to achieve combined rod and cone activation (ERGR+C) or in different phases to achieve ERGR and ERGC by means of triple silent substitution. After 30 min of dark adaptation, 8- and 15-Hz ERGR, ERGC, and ERGR+C responses were obtained at a mean luminance level of 24 scot. cd/m(2). Standard ISCEV ERGs were also obtained from each subject.
  
  
  
  The ISCEV and 15-Hz flicker ERGs were generally within the normal range for the carriers. The 8-Hz ERGR, ERGC, and ERGR+C amplitudes were also generally normal. In contrast, the carriers had ERGR, ERGC, and ERGR+C timing abnormalities, with phase advances beyond the range of normal for the ERGR (four carriers), ERGC (four carriers), and ERGR+C (three carriers). Only one carrier had normal 8-Hz responses under all conditions.
  
  
  
  The 8-Hz ERG timing abnormalities in five of six carriers indicate that retinal function is not necessarily normal in carriers of XLRS. The 8-Hz flicker ERG may be useful for studying retinal function in these individuals.
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, 1855 W. Taylor St., Chicago, IL, 60612, USA. jmcana1@uic.edu.|Department of Psychology, University of Illinois at Chicago, 1007 W. Harrison St., Chicago, IL, 60612, USA. jmcana1@uic.edu.|Department of Bioengineering, University of Illinois at Chicago, 851 South Morgan St., Chicago, IL, 60607, USA. jmcana1@uic.edu.
authors.forename: J Jason
authors.identifier: 0000-0003-1192-3487
authors.initials: JJ
authors.lastname: McAnany
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, 1855 W. Taylor St., Chicago, IL, 60612, USA.
authors.forename: Jason C
authors.initials: JC
authors.lastname: Park
authors.affiliation: The Pangere Center for Inherited Retinal Diseases, The Chicago Lighthouse, Chicago, IL, USA.
authors.forename: Frederick T
authors.initials: FT
authors.lastname: Collison
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, 1855 W. Taylor St., Chicago, IL, 60612, USA.|The Pangere Center for Inherited Retinal Diseases, The Chicago Lighthouse, Chicago, IL, USA.
authors.forename: Gerald A
authors.initials: GA
authors.lastname: Fishman
authors.affiliation: Stephen A. Wynn Institute for Vision Research, Department Ophthalmology and Visual Sciences, The University of Iowa, Iowa City, IA, USA.
authors.forename: Edwin M
authors.initials: EM
authors.lastname: Stone
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D003623:Dark Adaptation / Q000502:physiology; D004596:Electroretinography / Q000379:methods*; D005260:Female; D005425:Flicker Fusion / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010775:Photic Stimulation / Q000379:methods; D012160:Retina; D017949:Retinal Cone Photoreceptor Cells / Q000502:physiology*; D017948:Retinal Rod Photoreceptor Cells / Q000502:physiology*; D041441:Retinoschisis / Q000503:physiopathology*; D014785:Vision, Ocular / Q000502:physiology*
keywords: Cone; Electroretinogram (ERG); Flicker; Rod; X-linked retinoschisis