title: Predominant loss of the photopic negative response in central retinal artery occlusion.
abstract: OBJECTIVE
  To determine how the photopic negative response (PhNR) is affected in central retinal artery occlusion (CRAO).
  
  
  METHODS
  Observational case series.
  
  
  METHODS
  Seven patients with unilateral CRAO were included. Full-field scotopic and photopic electroretinograms (ERGs) including the PhNR were recorded. Each ERG amplitude in the affected eye was expressed as a percentage of amplitude of the corresponding wave in the unaffected eye.
  
  
  RESULTS
  Mean of the PhNR amplitude was reduced to 12.3 +/- 11.7% of that of unaffected eyes whereas the cone b-wave amplitude was attenuated to only 73.4 +/- 30.4%. This reduction of the PhNR amplitude was more significant than that of other waves including the rod b-wave, maximum a-wave and b-wave, cone a-wave and b-wave, and 30 Hz flicker ERG (P <.005).
  
  
  CONCLUSIONS
  The PhNR was severely affected in CRAO despite relative preservation of the cone b-wave, implicating massive loss of ganglion cells and their axons.
authors.affiliation: Department of Ophthalmology, Iwate Medical University, School of Medicine, 19-1 Uchimaru, Morioka, Iwate 020-8505, Japan. smachid@clubAA.com
authors.forename: Shigeki
authors.initials: S
authors.lastname: Machida
authors.forename: Yasutaka
authors.initials: Y
authors.lastname: Gotoh
authors.forename: Michiko
authors.initials: M
authors.lastname: Tanaka
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Tazawa
mesh_terms: D000368:Aged; D001369:Axons / Q000502:physiology*; D004596:Electroretinography; D005260:Female; D006801:Humans; D008027:Light; D008297:Male; D008875:Middle Aged; D015356:Retinal Artery Occlusion / Q000503:physiopathology*; D017949:Retinal Cone Photoreceptor Cells / Q000502:physiology; D012165:Retinal Ganglion Cells / Q000502:physiology*; D017948:Retinal Rod Photoreceptor Cells / Q000502:physiology; D014792:Visual Acuity