Developmental characteristics and control effects of myopia and eye diseases in children and adolescents: a school-based retrospective cohort study in Southwest China.

Objectives: To characterise the prevalence of myopia and eye diseases among school adolescents and children in Southwest China, and to evaluate the effectiveness of myopia control tools.

Design: Retrospective cohort study.

Setting: Across 95 basic education institutions in Southwest China.

Participants: 96 146 children aged 3-17 years from a school-based survey conducted between 2019 and 2021.

Primary Outcome Measures: The data of vision assessment and eye disease examination of school students were analysed, including a total of four surveys once per semester. The prevalence of myopia categorised as low (-0.5D to -3.0D), moderate (-3.0D to -6.0D) and high (≥-6.0D), along with the prevalence of significant ocular diseases, was assessed. Stratified analyses were conducted to investigate the impact of correction time on visual acuity (VA) and biological parameters. Subsequently, the subjects across the groups were matched using the nearest neighbour method, followed by multidimensional statistical analysis.

Results: The prevalence of myopia among the surveyed students was 38.39%. After controlling for confounding variables, the statistical analysis revealed a 0.1 increase in mean VA within the orthokeratology group and a 0.1 decrease in VA within the spectacle group (p<0.001), with statistically significant differences in corneal radius, corneal curvature and equivalent spherical lens (p<0.05). Multivariate analysis indicated a statistically significant reduction in VA in the ophthalmopathy group compared with the control group (p=0.031). Furthermore, it was demonstrated that the risk of eye disease during vision correction was greater among older students than their younger counterparts (OR>1), and that female students exhibited a higher risk than male students (OR=1.5).

Conclusions: The current high prevalence of myopia and eye diseases among Southwest China's school youths demands public health attention. Minors wearing orthokeratology lenses at night, especially in primary school, exhibit significantly improved naked-eye vision. However, vigilant eye healthcare during the correction period is crucial, especially for girls.