Myopia trends among children and adolescents: a nationwide study in South Korea

To evaluate gender disparities in the progression of myopia among children and adolescents in South Korea.

Nationwide cross-sectional data of 1,190 subjects aged 10-18 years was obtained for the years of 2011 (baseline) and 2021 using the Korea National Health and Nutrition Examination Surveys. The prevalence of myopia, as well as data regarding age, household income, height, weight, body mass index, and age of menarche, were evaluated. Myopia was defined as a spherical equivalent (SE) ≤ -0.5 D.

The prevalence of myopia among boys was stable in 2021 compared to 2011, with rates of 53.7% and 52.8%, respectively (P = 0.372). Among girls, however, there was a statistically significant increase in myopia prevalence in 2021 compared to 2011, with rates of 73.7% and 51.6% (P < 0.001), respectively. Over 10 years, the adjusted prevalence ratio for myopia in boys was 1.11 (95% CI, 0.77-1.61), whereas myopia prevalence in girls underwent a 1.87-fold increase over the same period (95% CI, 1.30-2.69), and menarche at 12 years of age or older was associated with less myopia in girls (PR = 0.84; 95% CI, 0.72-0.99). The spherical equivalent refraction in girls increased significantly over the same 10-year period, from -1.09 ± 0.13 D to -1.58 ± 0.17 D (P < 0.017), whereas in boys, there was no significant difference (P = 0.604).

In our study cohort, the prevalence of myopia increased significantly among girls compared with boys over the course of decade. Additionally, an association between early menarche in girls and the prevalence of myopia was observed.