A new, simple, inexpensive means of testing functional vitamin A status: the night vision threshold test (NVTT). A preliminary field-test report.
Vitamin A deficiency is the leading cause of preventable childhood blindness in developing countries. Each year, an estimated 13.5 million children world-wide are unable to adapt to the dark and half a million children progress to complete blindness annually from lack of vitamin A. Most of the currently available methods for assessing vitamin A status are expensive, require sophisticated instrumentation and are not efficacious in field conditions. A simple, inexpensive method was developed to identify children with defective dark-adaptability, thereby providing a reflection of marginal vitamin A stores. The purpose of this preliminary study was to test the field-efficacy of the Night Vision Threshold Tester (NVTT). Thirty-nine middle-school children with a mean age of 13.5 +/- 1.37 years were initially tested for their ability to adapt to the dark using the
Shrestha
A K
AK
The University of Arizona, College of Public Health, USA.
Duncan
B
B
Taren
D
D
Canfield
L M
LM
Greivenkamp
J E
JE
Shrestha
N
N
Shrestha
K K
KK
D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008297:Male; D009755:Night Blindness / Q000175:diagnosis* / Q000209:etiology; D016017:Odds Ratio; D012680:Sensitivity and Specificity; D014787:Vision Tests / Q000191:economics / Q000295:instrumentation* / Q000379:methods; D014801:Vitamin A / Q000627:therapeutic use; D014802:Vitamin A Deficiency / Q000150:complications / Q000175:diagnosis* / Q000188:drug therapy
D014801:Vitamin A