PUPILLARY AND VISUAL THRESHOLDS IN YOUNG-CHILDREN AS AN INDEX OF POPULATION VITAMIN-A STATUS

A prototype scotopic sensitivity machine was used to evaluate pupillar y and visual thresholds for 295 Indonesian children aged 1-5 y, most o f whom were initially vitamin A-deficient. Subjects were tested 6 and 9 mo after receiving a high dose of vitamin A. A group of 136 older ch ildren was tested at 6 mo after dosing; all subjects underwent testing at 9 mo. After testing at 9 mo, children randomly received either a s econd high dose of vitamin A or placebo and were tested a final time 2 wk later. Children with abnormal pupillary thresholds had significant ly higher relative dose responses (RDRs) (P < 0.01) and significantly lower serum retinol values (P = 0.05) than did normal children. The me an pupillary threshold rose leg, retinal sensitivity fell) as vitamin A status deteriorated between 6 and 9 mo after initial dosing, and was significantly different from a group of normal American children test ed previously (P < 0.001). After placebo-controlled dosing, the declin e in pupillary and visual thresholds (rise in retinal sensitivity) was significant for children receiving vitamin A but not for children rec eiving placebo.