Trends in Near Vision Loss and Age-Sex-SDI Disparities in Belt and Road Countries Over Thirty Years

PURPOSE: Near vision loss (NVL) inequalities are poorly understood across Belt and Road Initiative (BRI) countries, a socioeconomically diverse group. This study quantifies NVL burden and inequities by age, sex, and Socio-Demographic Index (SDI) in this network. METHODS: Using Global Burden of Disease 2021 (GBD 2021) estimates, we assessed NVL burden in 66 BRI countries from 1990 to 2021. Age-standardized rates were used for population comparisons and age-specific rates for age-stratified analyses. Trends were estimated using joinpoint regression. Estimates in younger age groups were treated as GBD-modeled epidemiological outputs and were not interpreted as clinical presbyopia. RESULTS: Higher NVL burden was concentrated in South Asia and Eastern Europe, with a persistent SDI gradient observed over time. From 1990 to 2021, NVL burden increased in India and Nepal, while Malaysia remained among the lowest. Several regions in Asia and Eastern Europe saw an increasing burden in the most recent decade. Sex disparities were evident, with women showing a higher NVL burden, particularly in lower-SDI regions. Age patterns showed prevalence peaking at 60-64 years and disability peaking at 55-59 years. Among the broad age bands analyzed, the largest modeled increase occurred in the 15-49-year age band. CONCLUSIONS: This study represents the first comprehensive analysis of NVL burden and disparities across BRI countries, revealing persistent inequalities by age, sex, and SDI. The findings reflect the diverse socio-economic and health‑care contexts of BRI countries and highlight the urgent need for targeted refractive services and healthy-aging strategies, especially for older women in low-SDI regions.