Investigating potential myopia risk factors, including chronotype, in Estonian adolescents

Abstract

AbstractPurposeTo evaluate chronotype, lifestyle factors, and parental myopia in relation to myopia, and characterise the effect of cycloplegia on spherical equivalent refraction (SER) in Estonian secondary school students.MethodsOne hundred twenty-three students aged between 15 and 17 years from three secondary schools in Estonia participated in the study. They underwent a comprehensive ocular examination, including cycloplegic refraction and ocular biometry. Chronotype was evaluated with the Morningness–Eveningness Questionnaire. Participants also completed a questionnaire about their daily activities, including time spent outdoors, time spent on near-work and mid-working distance activities, and parental myopia. Myopia was defined as cycloplegic SER ≤–0.50 D. Logistic regression analysis was performed to assess the association of the studied factors with myopia.ResultsIn a multivariate regression model, having two myopic parents was associated with higher odds of myopia (OR 3.78, 95% CI 1.15–12.42). We found no association between myopia and chronotype. Notably, time spent outdoors, and doing near-work and mid-working distance activities, did not affect the likelihood of having myopia. Non-cycloplegic SER was significantly more myopic than cycloplegic SER on average by 0.86 D (p< 0.0001, Wilcoxon matched-pairs signed rank test).ConclusionConsistent with previous reports, we identified parental myopia as a myopia risk factor. Chronotype was not associated with myopia in our study sample. Interestingly, there was no association between myopia and time spent outdoors or near work. Using non-cycloplegic refraction would lead to a significant overestimation of myopia.