Changing Epidemiology of Refractive Disorders in the Western Pacific Region, 1990-2023: Evidence From the Global Burden of Disease Study 2023.

Introduction: Refractive disorders (RDs) are a major cause of vision impairment worldwide. Although age-standardised rates have generally declined, the absolute burden, demographic drivers and future trends of RDs in the Western Pacific Region (WPR) remain incompletely characterised. This study assessed the long-term epidemiological patterns and projected burden of RDs in the WPR using data from the Global Burden of Disease Study 2023 (GBD 2023). Materials and Methods: Data on prevalent cases, prevalence and disability-adjusted life years (DALYs) due to RDs from 1990 to 2023 were obtained from GBD 2023. Age-standardised prevalence rates (ASPRs) and age-standardised DALY rates (ASDRs) were evaluated globally and across 31 countries and territories in the WPR. Temporal trends were assessed using estimated annual percentage change and joinpoint regression. Age- and sex-specific patterns were examined, and Shapley decomposition was used to quantify the contributions of population growth, population ageing and epidemiological change. ARIMA models were used to project ASPR and ASDR to 2030. Results: In the WPR, prevalent cases increased from 23.45 million in 1990 to 39.75 million in 2023, while ASPR declined from 1606.27 to 1382.90 per 100,000 population. DALYs increased from 1.09 million to 1.75 million, whereas ASDR declined from 76.00 to 59.85 per 100,000. Age-specific burden increased markedly with age, and females generally experienced a higher burden than males, particularly in middle and older age groups. Joinpoint analyses identified long-term declines in ASPR and ASDR but modest rebounds after 2019. Population growth was the dominant positive contributor to increasing absolute burden in most WPR countries, while population ageing contributed substantially, particularly in East Asia and among females; epidemiological change generally offset part of these demographic increases. By 2030, ASPR and ASDR in the WPR were projected to decline further to 1317.70 (95% PI 1282.64-1352.76) and 55.00 (95% PI 52.66-57.34) per 100,000, respectively. Conclusion: Despite declining age-standardised rates, the absolute burden of RDs in the WPR continues to increase under demographic pressure. Continued population growth and ageing, together with persistent age and sex disparities, indicate that declining rates alone may underestimate future eye-care needs. Monitoring both age-standardised and absolute burden, alongside effective refractive error coverage, will be important for regional planning and progress towards the WHO 2030 targets.