Global Trends and Projections for Avoidable Visual Impairment among Working-Age Individuals: A Population-Based Study

Abstract

Purpose: Visual impairment (VI) in working-age individuals significantly impacts public health and the economy. However, the avoidable causes, defined as cataract and refraction disorders, have not been extensively investigated. This study aims to quantify global trends, inequalities, and projections for avoidable VI among this demographic.

Design: Retrospective, observational, population-based trend study.

Methods: We derived data on avoidable VI prevalence and population size data in working age from the Global Burden of Disease (GBD) 2021 study. We employed the joinpoint regression analysis to assess trends from 1990 to 2021 by age, sex, sociodemographic index (SDI), type, and severity at the global, regional, and national levels. Cross-country inequalities were evaluated using the slope index of inequality and the health inequality concentration index. Subsequently, we performed Bayesian age-period-cohort modeling to estimate the avoidable BVL burden in working age by 2040.

Results: The prevalence of avoidable VI in working age decreased overall from 1990 to 2021, driven primarily by reductions in refraction disorders, with an average annual percentage change (AAPC) of -0.15 (95% confidence interval [CI], -0.18 to -0.12; P<0.001). We observed significant declines in severe vision loss and blindness, while moderate vision loss remained stable. Females exhibited a heavier burden of avoidable VI, but showed slower improvement compared to males. Socioeconomic disparities persisted, with lower SDI regions bearing a disproportionate burden, whereas the high SDI region showed an unfavorable increasing trend. From 1990 to 2021, the inequality slope index increased from 574.45 (95% CI, 914.95 to 233.95) to 652.27 (95% CI, 932.95 to 371.58), while the health inequality concentration index improved from -0.21 (95% CI, -0.26 to -0.17) to -0.17 (95% CI, -0.2 to -0.14). We project a continued decline in the global prevalence of avoidable working-age VI, but a 23.4% increase in avoidable VI cases by 2040, reaching approximately 146 million.

Conclusions: Despite overall declines in avoidable VI among working-age individuals, significant improvement opportunities and disparities persist. The anticipated increase in avoidable VI cases necessitates integrated eye health strategies, substantial investment in eye care services to enhance accessibility and affordability, and fair employment policies for the visually impaired.

Keywords: cataract; refraction disorders; visual impairment; working age.