Night vision in a case of vitamin A deficiency due to malabsorption.
Night vision was tested electroretinographically and psychophysically in a vitamin A deficient patient before and after therapy. Vitamin A deficiency resulted from malabsorption due to a jeujunoileal bypass operation. Before therapy the patient had severely reduced cone and rod function. After the reversal operation, accompanied by 5 injections of a total of 500,000 units of vitamin A, complete recovery of cone and rod functions was observed within 7 months. Shortly after therapy rod sensitivity reached the normal level, while the time course of rod adaptation remained slower than normal and the dark-adapted electroretinographic (ERG) responses were subnormal. At later stages the ERG responses reached normal amplitudes but rod adaptation stayed slow. Only after 7 months did night vision reach the normal level with regard to the time course of rod adaptation, rod sensitivity, and ERG responses.
D003623:Dark Adaptation; D004596:Electroretinography; D005260:Female; D006801:Humans; D007082:Ileum / Q000601:surgery; D007583:Jejunum / Q000601:surgery; D008286:Malabsorption Syndromes / Q000150:complications* / Q000209:etiology; D008875:Middle Aged; D009755:Night Blindness / Q000209:etiology*; D011183:Postoperative Complications; D014801:Vitamin A / Q000627:therapeutic use; D014802:Vitamin A Deficiency / Q000209:etiology* / Q000503:physiopathology
D014801:Vitamin A