A prevalence study of xerophthalmia in the Philippines: implications for supplementation strategies.

In three provinces of the Philippines (Quezon, Northern Samar and Zamboanga del Sur), 11,378 children between 6 and 83 months of age were examined for signs of xerophthalmia and weighed to determine weight-for-age status. Xerophthalmia prevalence ranged from 1.6% to 4.4% for nightblindness and 0.6% to 2.7% for Bilot's spots in the three provinces indicating a serious vitamin A deficiency problem. These levels contrast sharply with the recent national xerophthalmia prevalence (0.7% for night blindness and 0.2% for Bitot's spots). There was a preponderance of mild xerophthalmia among males, and among children 4-6 years of age. No consistent association between weight-for-age status and xerophthalmia was found. The study recommends the universal distribution of vitamin A to children in high-prevalence regions, rather than the current practice of providing vitamin A supplements to moderately and severely underweight children identified through the annual village-based child weighing sessions, to ensure reaching children most at risk for xerophthalmia. The study also suggests the need for regional vitamin A assessments to identify areas endemic for vitamin A deficiency because the aggregate national prevalence may mask a more serious localized problem.