2021 Global Burden of Disease Study: A Comprehensive Analysis of Glaucoma in the Middle-aged and Elderly Population at Global, Regional, and National Levels

Xiang Li^1*Guoxin Huang²Zhang Siqi¹Zhijie Zhang³Ran Li⁴Lei Zhu²Tang Jiafeng¹Jiaqi Wang²

• ¹Chongqing Three Gorges Vocational College, Wanzhou District, Chongqing, China
• ²Xiang Yang No.1 People’s Hospital, Xiangyang, China
• ³Kunming Medical University, Kunming, Yunnan Province, China
• ⁴Nanjing Medical University, Nanjing, Jiangsu Province, China

Background: Glaucoma is a leading cause of irreversible blindness globally, with a particularly significant impact on the middle-aged and elderly populations (ages 45+), substantially affecting their quality of life and imposing considerable socio-economic burdens. Comprehensive assessments of the burden of glaucoma specifically in this age group at global, regional, and national levels are crucial for shaping health policies and optimizing resource allocation. Methods: Data on the burden of glaucoma among individuals aged 45 and older were collected from the 2021 Global Burden of Disease (GBD) study. The Average Annual Percent Change (AAPC) was used to evaluate trends in glaucoma burden from 1990 to 2021 among this age group. The Slope Index of Inequality (SII) and the Concentration Index (CI) were employed to analyze both absolute and relative health inequalities in the burden of glaucoma. An Age-Period-Cohort model, specifically considering the 45+ age cohort, was fitted using the NORDPRED package to predict the future burden of glaucoma. Additionally, frontier analysis was conducted to assess the relationship between the burden of glaucoma and socio-demographic development in the older population, using non-parametric Data Envelopment Analysis (DEA) to define a boundary based on the level of development for the minimal achievable burden. Results: In 2021, there were 5.34 million cases of glaucoma in the global population aged 45 and older (95% UI: 4.22 million to 6.45 million), with an age-standardized prevalence rate (ASPR) of 889.3 per 100,000 population (95% UI: 700.2 to 1078.5). The AAPC for glaucoma in this age group from 1990 to 2021 was -0.82 (95% CI: -0.85 to 0.8), indicating a downward trend in both ASPR and Age-Standardized DALY Rate (ASDR) globally among the middle-aged and elderly. At the regional level, areas with lower Socio-Demographic Index (SDI) exhibited higher ASPRs, whereas high SDI regions recorded lower rates. Nationally, countries such as Niger and Nigeria demonstrated the highest age-standardized rates within this demographic. Health inequalities analyses showed that lower SDI countries bear a disproportionately higher burden of glaucoma among the middle-aged and elderly.