title: Negative scotopic ERG and photopic ERG ON response impairment in a patient with normal dark adaptation.
abstract: OBJECTIVE
  To present ocular findings in a patient who showed negative scotopic electroretinogram (ERG) and reduced ON response, but normal dark adaptation.
  
  
  METHODS
  An 18-year-old Japanese male patient who complained of severe asthenopia. His corrected visual acuities were 1.2 in both eyes. His fundi were normal. He had normal contrast sensitivity and normal dark adaptation.
  
  
  METHODS
  The patients underwent ERG (including the standard protocol and photopic long flash recordings).
  
  
  RESULTS
  The amplitudes of the rod ERG b-wave were reduced. The scotopic standard combined ERG response showed negative configuration. The photopic response to long flash revealed the reduced b-wave (ON response), while the amplitude of the first peak of the d-wave (OFF response) was within the normal range.
  
  
  CONCLUSIONS
  Postsynaptic abnormalities in both the rod and cone ON-pathways, which are often found in patients with night blindness, were suggested in the ERG findings, but the dark adaptation of our patient was normal. Neuromuscular evaluation of the patient and ophthalmological evaluation, including ERG, of his parents were normal. To our knowledge, the ophthalmological and electrophysiological findings of our patient cannot be attributed to any known clinical entity.
authors.affiliation: Division of Ophthalmology and Visual Science, Graduate School of Medical and Dental Sciences, Niigata University, 1-757 Asahimachi, Niigata, 951-8510, Japan. naoyuki.tanimoto@med.uni-tuebingen.de
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Tanimoto
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Usui
authors.forename: Mikio
authors.initials: M
authors.lastname: Ichibe
authors.forename: Manami
authors.initials: M
authors.lastname: Kuze
authors.forename: Mineo
authors.initials: M
authors.lastname: Takagi
authors.forename: Shigeru
authors.initials: S
authors.lastname: Hasegawa
authors.forename: Masahisa
authors.initials: M
authors.lastname: Sato
authors.forename: Keiko
authors.initials: K
authors.lastname: Tanaka
authors.forename: Haruki
authors.initials: H
authors.lastname: Abe
mesh_terms: D000221:Adaptation, Ocular; D000293:Adolescent; D001248:Asthenopia / Q000175:diagnosis* / Q000503:physiopathology; D003623:Dark Adaptation; D004596:Electroretinography / Q000379:methods*; D006801:Humans; D008297:Male; D010775:Photic Stimulation / Q000379:methods; D014792:Visual Acuity