Probability of myopia in children with high refined carbohydrates consumption in France

Background: Evaluate risk factors for paediatric myopia in a contemporary French cohort taking into account consumption of refined carbohydrates (starches and sugars).

Methods: An epidemiological cross-sectional study was conducted between May 2017 and May 2018. Two hundred sixty-four children aged 4 to 18 years attending the Centre Hospitalier Universitaire Gui de Chauliac in Montpellier were recruited. Ophthalmologic or optometric cycloplegic refraction were measured. Evaluated risk factors for myopia were collected, including family history of myopia, outdoor time, reading time, screen time, physical activity, and consumption of refined carbohydrates. Association between the probability of at least one eye showing myopia (defined as < 0 D) and frequency of refined carbohydrates consumption adjusted for risk factors and control factors was tested.

Results: Overall, 86/264 (32.6%) children investigated showed myopia in at least one eye. We included 180 children exhibiting refraction < 3 D in both eyes: 88 (48.9%) girls and 92 (51.1%) boys. The consumption of refined carbohydrates significantly increased the probability of myopia for girls (odds ratio [OR] = 1.07; 95% confidence interval [CI], 1.02-1.13; P = 0.009) but decreased it for boys (OR = 0.94; 95% CI, 0.89-0.98; P = 0.011). The probability of myopia was marginally increased with increased screen time (OR = 2.32; 95% CI, 0.94-6.47; P = 0.083). Outdoor time seemed marginally protective (OR = 0.74; 95% CI, 0.54-1.01; P = 0.057).

Conclusion: Refined carbohydrates consumption could be associated with child myopia, with increased probability for girls and unexpected reduced probability for boys, possibly due to the fact that frequency of carbohydrates consumption do not really capture boy's chronic hyperglycemia, boys being more physically active than girls at all ages. Some known risk/protective factors of myopia were marginally significant: screen time (risk) and outdoor time (protective). This study reinforces the belief that modifiable risk factors for myopia could be targets for future public health actions.

Keywords: Children; Diet; Myopia; Outdoor time; Refined carbohydrates; Risk factors; Screen time; Starch; Sugar.