Association Between Breastfeeding and Likelihood of Myopia in 6-7 Years Old Children

Myopia is the main reason of vision loss in the world which is seen in 30.4 million adults in USA (1). In a myopic eye, images are focused in front of retina because, cornea and crystalline lens become more powerful in focusing the image or the eye axis become too long (axial myopia) (2). Myopia prevalence in adolescents has been raised in recent years and nowadays it has reached to 10-25% and 60-80% in western and eastern countries respectively (3). Tehran eye study showed that the prevalence of myopia in Tehran is 21.8% and 17.2% based on manifest and cycloplegic refraction respectively (4). One study in Dezful, Iran showed that 3.7% of 7-15 years old children are myopic (5). Today potential role of early life nutrition in myopia development in later life is becoming an attractive field of study. It has been shown that until weaning; breast milk is the main source of many nutrients \[such as docosahexaenoic acid (DHA)\] which are important for photoreceptors and cortical neuronal development (6). But results about the relationship between breastfeeding and likelihood of childhood myopia are controversial. A hypothesis-generating study (7) showed an independent and inverse relationship between breastfeeding and likelihood of myopia in 10-12 year old Singaporean children. However, data pulled from three English birth cohorts done in 10-11y and 15-16y children did not show any effect (8). To examine the association between breastfeeding pattern and likelihood of myopia in 6-7y children, a retrospective case-control study is designed in National Nutrition and Food Technology research Institute of Iran. This study will try to assess breastfeeding pattern and almost all cofactors which may relate to myopia.