title: Improvement of scotopic electroretinograms and night blindness with recovery of serum zinc levels.
abstract: BACKGROUND
  We sought to determine the cause of reduced scotopic and photopic electroretinograms (ERGs) and night blindness in a 46-year-old man with liver dysfunction but no history of alcoholism.
  
  
  METHODS
  A 46-year-old Japanese man with a complaint of visual difficulties in dim light for 1 month.
  
  
  METHODS
  By electrophysiological investigation, the patient was found to have low levels of serum zinc and vitamin A on admission. The rod b wave was unrecordable, and the bright-flash ERGs were reduced, with the a wave > b wave. The amplitudes of the cone and 30-Hz flicker responses were also reduced, and their implicit times were prolonged. Three weeks after admission, the patient's serum zinc level recovered to normal levels, but his serum vitamin A level was still low. The symptoms of night blindness were gone, and the rod ERGs and single bright-flash responses were within normal limits. However, the cone ERGs and 30-Hz flicker responses were still depressed.
  
  
  CONCLUSIONS
  The recovery of scotopic function together with the recovery of zinc but not vitamin A levels suggests that the ERG changes were most likely related to low zinc levels.
authors.affiliation: Department of Ophthalmology, JA Gifu Koseren, Chuno General Hospital, Gifu, Japan. mochi-gif@umin.ac.jp.|Department of Ophthalmology, JA Gifu Koseren, Chuno General Hospital, 5-1 Wakakusa-dori, Seki-shi, Gifu, 501-3802, Japan. mochi-gif@umin.ac.jp.
authors.forename: Kiyofumi
authors.initials: K
authors.lastname: Mochizuki
authors.affiliation: Department of Ophthalmology, JA Gifu Koseren, Chuno General Hospital, Gifu, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Murase
authors.affiliation: Department of Internal Medicine, JA Gifu Koseren, Chuno General Hospital, Gifu, Japan.
authors.forename: Motoaki
authors.initials: M
authors.lastname: Imose
authors.affiliation: Department of Ophthalmology, Gifu University School of Medicine, Gifu, Japan.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Kawakami
authors.affiliation: Department of Ophthalmology, Gifu University School of Medicine, Gifu, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Sawada
mesh_terms: D002756:Cholagogues and Choleretics / Q000008:administration & dosage; D003623:Dark Adaptation; D004596:Electroretinography; D005451:Fluorescein Angiography; D006801:Humans; D008111:Liver Function Tests; D008297:Male; D008875:Middle Aged; D009755:Night Blindness / Q000097:blood / Q000503:physiopathology*; D010775:Photic Stimulation; D020419:Photoreceptor Cells, Vertebrate / Q000502:physiology*; D020127:Recovery of Function; D014794:Visual Fields; D014801:Vitamin A / Q000097:blood; D014802:Vitamin A Deficiency / Q000097:blood; D015032:Zinc / Q000097:blood* / Q000172:deficiency
chemical_list: D002756:Cholagogues and Choleretics; D014801:Vitamin A; D015032:Zinc