Date of Award
Master of Science in Vision Science
Diane P Yolton
Night blindness is a frequent patient complaint. Vitamin A deficiency has long been known to cause night blindness. More recently, zinc deficiency~y has also been shown to cause night blindness. Diagnosis of nutritional night blindness is made difficult however, by the lack of associated clinical signs, especially in the case of margirial deficiences. In order to identify those tests the practitioner should conduct when nutritional night blindness is suspected, results from several diagnostic tests were compared between a group of patients with the complaint of night blindness, and an age and sex matched group without the complaint. Dark adaptometry testing, the classical test for night blindness, confirmed that the patient complaint, when properly elicited, is of high validity in diagnosis of night blindness. The American Automobile Association's Night Sight Meter, a screening device, was found to produce results which correlated significantly with dark adaptometry results, but was of little value as a screening test for night blindness. ·Results from nutritional testing showed no differences between the two groups for serum vitamin A, concentration vitamin A intake .as assessed by diet survey, or zinc 1-eve.ls .from ... ha.ir analysis. It was concluded, therefore, that dietary supplementation may be the test of choice in evaluation of nutritional sufficiency.
Hirons, Roger R., "Clinical management of nutritional nightblindness" (1982). College of Optometry. 588.