Global and Regional Burden of Refraction Disorders In Children, Adolescents and Young Adults from 1990 to 2021: Trends, Inequalities and Future Predictions with Machine Learning.

PURPOSE: This study aims to forecast future trends and quantify the contributions of key determinants, extending current evidence for tailored interventions METHODS: The study used data from the Global Burden of Disease Study 2021 for children, adolescents and young adults aged 0-24 years. Temporal trends were analysed with joinpoint regression, while health inequalities were assessed using the slope index of inequality (SII) and concentration index (CIx). Bayesian age-period-cohort (BAPC) modelling and XGBoost were employed to project prevalence and years lived with disability (YLDs) and SHAP values were used to quantify the contributions of key predictors. RESULTS: A slight but significant global decrease was observed in both prevalence (average annual percent change, AAPC: -0.05%) and YLD rates (AAPC: -0.08%) from 1990 to 2021. Females consistently exhibited higher burden than males, though both groups showed significant reductions. In 2021, the prevalence rate was highest in the 15-19 year age group and YLDs were highest in the 20-24 year age group. A positive correlation was observed between the socio-demographic index (SDI) and both prevalence (r = 0.44) and YLDs rates (r = 0.43). Socioeconomic disparities widened over time, as indicated by an increase in the SII for prevalence (from 497.98 to 525.10) and YLDs (from 15.46 to 16.53), alongside a decline in the CIx for prevalence (from -0.075 to -0.091) and YLDs (from -0.065 to -0.083). In predictive modelling, age emerged as the strongest predictor of disease burden, followed by year, SDI, GDP and sex. CONCLUSION: The global burden of refraction disorders is declining yet marked by significant inequalities. Mitigating this burden requires tailored strategies, shifting from primary prevention in high-SDI regions to ensuring access to affordable corrections in low-SDI settings.