Prevalence of myopia and refractive parameters among children and adolescents in Hi-tech District of Chengdu City (2021-2023)

Abstract Objective: To analyze the prevalence of myopia among children and adolescents in Chengdu from 2021 to 2023, providing insights for myopia prevention and control. Methods: This study was a school-based cross-sectional study in children and adolescents aged 3–18 years in Hi-tech District of Chengdu City. All the students underwent comprehensive ocular measurement, including visual acuity (VA),spherical equivalent error (SER) with noncycloplegic autorefraction, axial length (AL) and corneal radius (CR) . Results:Over the three-year study period from 2021 to 2023, the overall prevalence of myopia was 38.15%, with annual rates of 38.74% in 2021, 38.67% in 2022, and 37.4% in 2023. The prevalence of myopia and high myopia increased significantly with age (P < 0.001). In 2021, myopia prevalence was 37.4% among boys and 40.17% among girls; in 2022, 38.05% among boys and 39.43% among girls; and in 2023, 35.85% among boys and 38.33% among girls, consistently higher in girls each year (P < 0.001). Myopia prevalence increased with school level (P < 0.001). Mild myopia was the most common (24.47%), followed by moderate (10.77%) and severe myopia (2.91%). The SER varied, with mean values of -1.72 ± 1.57 D in 2021, -1.32 ± 1.51 D in 2022, and -1.42 ± 1.36 D in 2023 (P < 0.001), decreasing significantly with age (P < 0.001). Axial length (AL) was stable across most age groups, with total AL values of 23.80 ± 1.02 mm in 2021, 23.79 ± 1.04 mm in 2022, and 23.81 ± 1.04 mm in 2023. Conclusion: Myopic prevalence among children and adolescents in Hi-tech District of Chengdu City was shown to be steadily decreasing from 2021 to 2023. The prevalence increased with age and school level, indicating a need for targeted interventions. Significant changes in spherical equivalent refraction and axial length underscore the importance of early intervention and regular monitoring to manage myopia effectively.