The ocular effects of vitamin a deficiency in man in the tropics

Response of Bitot's spots in preschool children to vitamin A treatment

In a double-masked, placebo-controlled, clinical trial in Indonesia, 88 preschool children between the ages of 36 and 72 months with Bitot's spots were randomly assigned to 200,000 IU of oral vitamin A or placebo and followed up for five weeks. Baseline and follow-up serum vitamin A levels were obtained. Of the 45 children receiving vitamin A, 33 (73.3%) showed complete cure and disappearance of Bitot's spots, six (13.3%) had disappearance of some but not all Bitot's spots, and six (13.3%) were unresponsive to treatment. The nonresponsive children were older, all male, and had higher initial mean serum vitamin A levels, 23.0 micrograms/dl, compared to 15.9 micrograms/dl in the cured group (P = .017). These data suggest that normal vitamin A status may be found in approximately 13% of children with Bitot's spots before vitamin A intervention and that one fourth of those who had Bitot's spots originally will not be cured of all Bitot's spots after intervention. These are important factors to consider when using Bitot's spots in prevalence surveys as a clinical sign of vitamin A deficiency.

Keratomalacia

Xerophthalmia and keratomalacia are public health problems of great magnitude which are usually associated with multiple vitamin and protein deficiencies. The authors report the case of a 27-year-old commune member who subjected herself to a bizarre protein and vitamin deficient diet for many months. This ultimately produced nyctalopia, xerophthalmia and keratomalacia with bilateral corneal perforation. Despite therapy, she remained comatose and expired shortly after admission. Ocular pathological changes included bilateral corneal melting with prolapse of intraocular contents, conjunctival epidermidalization, goblet cell atrophy and thinning of the outer nuclear layer of the retina. It is noted that ocular findings in pure avitaminosis A produced experimentalyy include epithelial atrophy followed by keratinization.