The influence of low birth weight on the prevalence of refractive errors among schoolchildren.

PURPOSE: The aim of the study was to determine in a large population whether low birth weight has an influence on the prevalence of refractive errors among schoolchildren. MATERIAL AND METHODS: 3663 schoolchildren were examined (1738 boys and 1925 girls, aged 6-17 years, mean age 11.1, SD = 3.2). The weight at birth was 1500-2500 grams (mean 2184, SD = 271) in 254 and more than 2500 grams (mean 3398, SD = 441) in the remaining 3409 children. Skiascopy with cycloplegia was done and refractive error readings were reported as the spherical equivalent (SE). Myopia was defined as SE < or = -0.5 D, hyperopia as SE > or = +1.5 D. Anisometropia was diagnosed when the difference in the refraction of both eyes was > 1.0 D. The parents completed a questionnaire on the child's weight and term of birth. Data analysis was performed using chi-square test. P values of less than 0.05 were considered statistically significant. RESULTS: Hyperopia was observed more frequently in 6-7 year-old children whose birth weight was > 2500 grams (p < 0.05) - table 1. Additionally, it was found that anisometropia was less frequent in 10-11 year-old children whose birth weight was > 2500 g (p < 0.05) - table 2. CONCLUSION: Low birth weight may have an effect on the prevalence of refractive errors among schoolchidren.