Visual Impairment in Working-Age Individuals Increased Over Past 3 Decades

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The global prevalence of visual impairment among working-age individuals experienced a progressive increase in the last three decades and is projected to continue its trajectory, according to new research.¹

A cross-sectional, population-based study obtained data on individuals aged 15 to 64 years from 204 countries and territories in the Global Burden of Disease 2019 study. Analyses of the data revealed approximately 438,00,000 cases of global visual impairment in 2019, illustrating a 91.46% increase in the number of cases since 1990.

“Because of its association with general health and employment prospects, visual impairment in working-age individuals has gradually become a major public health problem,” wrote the investigative team, led by Yingting Zhu, MD, PhD and Wenmin Huang, MD, State State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University.

A minimum of 2.2 billion people worldwide experience some form of visual impairment, according to a global study conducted by the World Health Organization (WHO) in 2019.² Among individuals of working age, visual impairment can reduce employment prospects and health, with decreased social and economic productivity as a downstream effect. However, the long-term global patterns of visual impairment prevalence among this population and investigators into these patterns appears limited and have not been well-documented.

For this analysis, Zhu and colleagues examined the patterns of visual impairment prevalence and associated disability-adjusted life-years (DALYs) among people aged 15 to 64 years from 1990 to 2019.¹ Visual impairment was defined as visual acuity of <6/18 (20/60), according to the Snellen chart, or near visual acuity of <6/12 (20/40) distance equivalent.

Temporal trends of the visual impairment burden were calculated by the estimated annual percent changes (EAPCs) and analyzed at global, regional, and national levels, and stratified according to age group, sex, and sociodemographic index (SDI).

“This analysis may serve as a catalyst for the advancement of current and development of novel prevention and treatment strategies aimed at alleviating the health hazards associated with visual impairment among working-age individuals, which may have substantial outcomes with regard to personal well-being and socioeconomic productivity,” investigators wrote.

Upon analysis, investigators found 437,539,484 (95% uncertainty interval [UI], 325,463,851 - 575,573,588) prevalent cases of global visual impairment in 2019 (53.12% female). This represented an increase of 91.46% from 1990, in which there were 228,530,964 prevalent cases (95% UI, 172,515,833 - 297,118,596).

The increase in the number of prevalent cases of visual impairment was noted in all age groups, with the largest increase (114.38%) observed in the 45-to-49-year group. During those 3 decades, visual impairment-associated DALYs also increased from 7,601,852 (95% UI, 5,047,030 - 11,107,897) in 1990 to 12,563,276 (95% UI, 8,278,866 - 18,961,723) in 2019.

Among the 5 SDI groups (Low, Low-middle, Middle, High-Middle, High), the low-SDI group experienced the largest increase in DALYs from 1990 (898,167 [95% UI, 597,161 - 1,301,931]) to 2019 (1,634,122 [95% UI, 1,079,102 - 2,444,381). The greatest regional increase in visual impairment prevalence was identified in Eastern Europe (EAPC, 0.10; 95% CI, 0.02 - 0.19).

But, among all 204 countries and territories, Nepal exhibited the highest national prevalence of visual impairment per 100,000 population in 2019 (26,008.45; 95% UI, 19,987.35 - 32,482.09) and South Sudan showed the highest DALY rate per 100,000 population (480.59; 95% UI, 316.06 - 697.06).

Zhu and colleagues noted the correlation between visual impairment in working-age individuals and their personal and social well-being requires further research. The team suggested these data might assist in the development of strategies to limit the burden of visual impairment globally.

“As this study offers valuable insights into the disease burden in this population in various regions and countries with diverse development levels, it could assist policy makers and clinicians in formulating suitable strategies for visual impairment prevention and treatment,” investigators wrote.

References

1. _{Chen J, Yang C, Zheng W, et al. Global, Regional, and National Epidemiology of Visual Impairment in Working-Age Individuals, 1990-2019. JAMA Ophthalmol. Published online December 07, 2023. doi:10.1001/jamaophthalmol.2023.5617}
2. _{Blindness and vision impairment. World Health Organization. Accessed December 7, 2023. https://www.who.int/news-room/fact-sheets/detail/blindness-and-visual-impairment}