Global prevalence and years lived with disability (YLDs) of cataract in 204 countries and territories: findings from the Global Burden of Disease Study 2021.

Background: Cataracts, the leading cause of blindness globally, significantly impair vision and quality of life, particularly among the elderly. Despite advancements in cataract surgery, challenges in accessibility and economic disparities hinder the reduction of cataract burden, especially in low-income regions. This study examines the global prevalence and years lived with disability (YLDs) due to cataracts from 1990 to 2021, providing insights to inform public health strategies.

Methods: Utilizing data from the Global Burden of Disease (GBD) Study 2021, we analysed cataract prevalence and YLDs across 204 countries and territories. The estimates were stratified by age, sex, region, and Socio-Demographic Index (SDI) and compared across different time periods. Age-standardized rates (ASRs) and average annual percentage changes (AAPCs) were calculated to evaluate trends.

Results: From 1990 to 2021, the global YLDs due to cataracts increased from 3.42 million to 6.55 million, a 91.8% rise. Most countries exhibited an increase in YLDs, with notable surges in low-SDI regions like Sub-Saharan Africa and South Asia. The AAPC for age-standardized prevalence rate (ASPR) was slightly positive globally, while the age-standardized YLD rate (ASYR) showed a decreasing trend, indicating improved cataract management. High-SDI regions experienced minor ASPR increases but significant ASYR reductions, reflecting effective interventions. Conversely, low-SDI regions saw declines in both ASPR and ASYR, though disparities persisted.

Conclusion: The burden of cataracts remains substantial, with significant increases in YLDs driven by aging populations and improved diagnostic capabilities. Effective management strategies have reduced ASYRs, particularly in high-SDI regions. Addressing cataract burden in low-SDI regions requires enhanced healthcare access, targeted public health interventions, and global support. These findings underscore the need for continued investment in cataract prevention and treatment to mitigate the global impact.