History of nightblindness: a simple tool for xerophthalmia screening

Abstract

Among 5925 preschool-age children examined in a house to house rural field study, X1B (Bitot's spot with xerosis) and/or an history of nightblindness (XN) was presented in 325. Mean serum vitamin A levels among those with isolated XN (13.9 microgram/dl), isolated X1B (13.4 micrograms/dl), and coexistent XN/X1B (12.1 microgram/dl) were similar, and significantly below that of normal age/sex/neighborhood matched controls (17.6, 17.1, and 18.3 microgram/dl, respectively). The mean serum vitamin A level of the matched controls was significantly below that of normal, randomly sampled children from the study population as a whole (20.6 microgarm/dl). As independent screening criteria, disregarding the presence of absence of other signs, twice as many children had a history of XN as had X1B (84 and 41% of all clinically abnormal children, respectively). Of randomly sampled children 55% but only 15% of cases of XN had serum vitamin A levels above 20 microgram/dl. Of children with a history of nightblindness 97% had impaired scotopic vision on objective testing, but the mean serum vitamin A levels among test positives and negatives were identical. These results suggest a properly eleicited history of nightblindness can be almost as specific and far more sensitive an index of vitamin A deficiency and early xerophthalmia than the prescence of Bitot's spots (X1B), and that vitamin A deficiency is a clustered, neighborhood phenomenon rather than an isolated, sporadic occurrence.

Risk factors for nightblindness among women of childbearing age in Cambodia

“…The literal translation of kwak moin in Cambodian is 'chicken blindness.' A history of nightblindness has been shown to be a reliable indicator of vitamin A deficiency in surveys (Sommer et al, 1980). Other questions included a history of diarrhea in the last 2 weeks, consumption of eggs, dark-green leafy vegetables, carrots, ripe papaya, ripe mango, pumpkin, sweet potato, etc.…”

Nutritional ocular diseases and their association with diarrhoea in Matlab, Bangladesh

“…Sommer et al (1981) found that, in Indonesia, between two and five pre-school children per 1000 had nutritional corneal lesions, and fifty-five per 1000 had conjunctival xerosis (XIA) plus Bitot's spot (XIB) with a history of night blindness (XN; Sommer et al 1978). It has been reported by the Institute of Nutrition and Food Science, University of Dhaka (1977), that in 90% of families in Bangladesh the intake of vitamin A is less than 70% of that required, and 5% of all children suffer from night blindness.…”

Análise crítica de estudos brasileiros sobre deficiência de vitamina A no grupo materno-infantil

“…Observa-se, ainda, discrepância das tendências epidemiológicas descritas quanto ao declínio da desnutrição energética e protéica no Brasil (47) . Os estudos realizados em diferentes partes do país têm sido eficazes na medida em que identificam os grupos mais vulneráveis à carência de micronutrientes (9,48,49) , não havendo diferenças marcantes na ocorrência desta deficiência entre as diversas regiões. Isso significa que a deficiência não está restrita às camadas da população menos favorecidas, indicando haver uma história independente em relação ao curso histórico da desnutrição energética e protéica.…”