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.

CASE:

A 46-year-old Japanese man with a complaint of visual difficulties in dim light for 1 month.

OBSERVATIONS:

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: Kiyofumi Mochizuki, Hiroki Murase, Motoaki Imose, Hideaki Kawakami, Akira Sawada
• Journal: Japanese journal of ophthalmology (Jpn J Ophthalmol) 2006 Nov-Dec Vol. 50 Issue 6 Pg. 532-536 ISSN: 0021-5155 [Print] Japan
• PMID: 17180528 (Publication Type: Case Reports, Journal Article)

Chemical References

• Cholagogues and Choleretics
• Vitamin A
• Zinc

Topics

• Cholagogues and Choleretics (administration & dosage)
• Dark Adaptation
• Electroretinography
• Fluorescein Angiography
• Humans
• Liver Function Tests
• Male
• Middle Aged
• Night Blindness (blood, physiopathology)
• Photic Stimulation
• Photoreceptor Cells, Vertebrate (physiology)
• Recovery of Function
• Visual Fields
• Vitamin A (blood)
• Vitamin A Deficiency (blood)
• Zinc (blood, deficiency)