The Lack of Association of Breastfeeding and Myopia in Children and Adolescents: Finding from a School-Based Study and a Meta-Analysis of the Literature.

We aimed to assess the relationship between breastfeeding and myopia in a school-based study in rural China. In addition, we performed a systematic review and meta-analysis to confirm the association from available observational studies. The school-based study of 2,346 grade 7 students (mean age: 13.8 years) was conducted in southwestern part of China. Myopia was defined as spherical equivalent of less than -0.50 diopter and information regarding breastfeeding was ascertained through a questionnaire. We also performed the literature search in three databases (PubMed, EMBASE, and Cochrane Central Register of Controlled Trials) and reference lists of retrieved studies. Effect estimates were pooled using random-effects models. In our school-based study, the association between breastfeeding and myopia was marginally nonsignificant after adjusting for potential confounders, including gender, body mass index, parental myopia, time for reading and writing after school, and time outdoors (odds ratio = 0.75, 95% confidence interval: 0.55-1.04,  = 0.09). In the meta-analysis of eight studies, no significant association was observed. Current evidence did not support that breastfeeding could reduce the risk of myopia in children and adolescents.