Height, Nutrition and Refractive Error Among Rural Chinese School Children: The See Well to Learn Well Project

Abstract

Purpose: : To examine the plausibility of the hypothesis that longitudinal changes in nutritional status are partly responsible for observed increases in myopia prevalence among Chinese children.

Methods: : Rural Chinese secondary school children participating in a population-based randomized trial of interventions to promote spectacle use were randomly sampled (20% of children with uncorrected vision > 6/12 bilaterally, and 100% of remaining children), and underwent cycloplegic refraction with refinement by an ophthalmologist and measurement of height and weight. Stunting was defined according to a WHO standard population.

Results: : Among 3226 childen in the sample frame, 2905 (90.0%) took part in the survey. Among 1477 children selected for refraction, 1371 (92.8%) had height and weight measurements. Children had a mean age of 14.5 +/- 1.4 years, 59.8% were girls, and mean spherical equivalent refraction was -1.93 +/- 1.82 D. Stunting was present in 87 children (6.4%). While height was inversely associated with refractive error (taller children were more myopic) among boys (r = -0.147, p = 0.001), no such association was observe among girls, neither girls nor boys with stunting differed significantly in refractive error from children without stunting, and neither stunting nor height were associated with refractive error when adjusting for age, height and parental education. The power of this study to have detected a 0.75 D difference in refractive error between children with and without stunting was 0.96.

Conclusions: : Results from this cross-sectional study are not consistent with the hypothesis that nutritional status is a strong determinant of refractive error in this setting.

Clinical Trial: : http://www.cct.cuhk.edu.hk CUHK_CCT00149

Keywords: refractive error development • visual development: infancy and childhood