The global burden of blindness and vision loss has increased among the 50% of the world’s population with the lowest-income from 1990 to 2019, according to an analysis published in the British Journal of Ophthalmology. Women suffer a greater burden of blindness and vision loss compared with men, according to the report.
Researchers conducted a secondary analysis of the Global Burden of Diseases, Injuries and Risk Factors Study (GBD) 2019. They extracted data for disability-adjusted life-years (DALYs) due to blindness and vision loss from the GBD 2019.
The research team extracted data for gross domestic product per capita from the World Bank database and they computed slope index of inequality (SII) and concentration index to evaluate absolute and relative cross-national health inequality, respectively.
The researchers found that blindness and vision loss were estimated to affect 801.2 (95% UI 662.0 to 949.3) million people globally.
Compared with men, women suffered a greater burden of blindness and vision loss, even age-adjusted, for all vision-threatening diseases except for glaucoma.
When stratified by age, the burden of blindness and vision loss measured in DALYs was highest in the 65 to 69 years age group in both 1990 and 2019. Following adjustment for the effect of population size in each age group, the DALYs were observed to increase with age.
Countries with high, high-middle, middle, low-middle and low socio-demographic index showed a decrease in age-standardized DALY rate of 4.3%, 5.2%, 16.0%, 21.4% and 11.30% from 1990 to 2019, respectively.
The poorest 50% of the global population had 59.0% and 66.2% of the burden of blindness and vision loss in 1990 and 2019, respectively.
The absolute cross-national inequality (SII) fell from −303.5 (95% CI −370.8 to −236.2) in 1990 to −256.0 (95% CI −288.1 to −223.8) in 2019, while the relative inequality (concentration index) for global blindness and vision loss was essentially constant between 1991 (−0.197, 95%CI −0.234 to −0.160) and 2019 (−0.193, 95% CI −0.216 to −0.169), the report shows.
Study limitations include an underestimation of the total burden of blindness and vision loss, weaknesses regarding GBD data source and methodology, including limited quality of data and lack of population-based data, particularly in poor regions, and the research was also limited by the ecological fallacy due to all conclusions being derived from national-level data, instead of individual-level data.
“In conclusion, this study found that despite social development, the overall blindness burden and its disproportionate concentration in LMICs remained severe, highlighting limitations of global action plans from the perspective of inequality,” according to the researchers. “This pervasive and persistent inequality needs to be addressed, with a special focus on the poor, elderly and women, in order to eliminate avoidable blindness and achieve the ultimate goal of Universal Eye Health.”
Li Y, Wang H, Guan Z, et al. Persistence of severe global inequalities in the burden of blindness and vision loss from 1990 to 2019: findings from the Global Burden of Disease Study 2019. Br J Ophthalmol. Published online July 9, 2023. doi:10.1136/bjo-2022-321801