Prevalence of Glaucoma, POAG Associated With Age, Race in California Medicare Beneficiaries

Primary open-angle glaucoma (POAG) and glaucoma had various causes, including age, race, and sex that could indicate that more resources should be focused on improving access to care and investigate undiagnosed glaucoma, according to a study published in American Journal of Ophthalmology.

The leading cause of permanent vision loss in the United States and worldwide is glaucoma. There have been past studies that have evaluated the prevalence of glaucoma in different populations throughout the United States, but the prevalence of glaucoma is still not widely understood. This study aimed to use the 2019 California Medicare population to identify the factors associated with glaucoma by examining prevalence and severity levels.

Glaucoma | Image credit: reineg - stock.adobe.com

Medicare beneficiaries in California who were aged 65 years and older were included in this study; individuals with Part A or Part B coverage were included. The Charlson Comorbidity Index (CCI) score, age, sex, and race were evaluated as predictors for glaucoma. Age was separated into 5 different age groups and race was separated into non-Hispanic White, Black, Hispanic/Latino, Asian, and Other/Unknown. Primary outcomes included the presence of glaucoma, POAG, secondary open-angle glaucoma (SOAG), and angle closure glaucoma (ACG) with each type of glaucoma examined and classified by severity of mild, moderate, severe, and unknown.

There were 5,856,491 beneficiaries from the 2019 California Medicare database included in the study. A total of 31.2% were aged 65 to 69 years, 54.8% were female, 57.0% were non-Hispanic White, and 69.6% had a score of 0 in CCI. There were a total of 3.8% of the participants who had any type of glaucoma, with 2.9% reporting POAG, and 0.2% reporting in both ACG and SOAG. Moderate glaucoma was the most frequently reported severity (31.0% in any glaucoma, 36.4% in POAG). Severe glaucoma was reported the most in individuals with SOAG (28.7%) and ACG (24.4%).

The prevalence of glaucoma increased with age, was more prevalent in female beneficiaries, and most prevalent in Asian individuals (5.2%) for glaucoma, POAG, and ACG; SOAG was most prevalent in non-Hispanic White individuals (0.2%). The prevalence of glaucoma increased as the systemic disease burden increased in CCI score.

An association was found between increased odds of glaucoma and older age (adjusted odds ratio [aOR], 2.03; 95% CI, 2.00-2.06 for those aged 85 years and older compared with those aged 65 to 69 years); this same association was found in POAG (aOR, 2.23; 95% CI, 2.20-2.27). Higher odds for glaucoma (aOR, 1.03; 95% CI, 1.02-1.04), POAG (aOR, 1.01; 95% CI, 1.00-1.02), and ACG (aOR, 1.36; 95% CI, 1.31-1.41) were found in females; however, this association was not found in SOAG (aOR, 0.99; 95% CI, 0.95-1.03).

There were also higher odds of glaucoma (aOR, 1.70; 95% CI, 1.67-1.73) and POAG (aOR, 1.79; 95% CI, 1.75-1.83) in Black beneficiaries and higher odds of ACG (aOR, 5.09; 95% CI, 4.89-5.30) in Asian individuals compared with non-Hispanic White. Higher CCI score also increased the odds of any glaucoma (aOR, 5.59; 95% CI, 5.51-5.67) and POAG (aOR, 5.21; 95% CI, 5.13-5.30) when the beneficiaries had a CCI score of 5 or more.

There were some limitations to this study. There is a possibility that the Medicare database did not capture all patients aged 65 yearns and older who receive eye care, which could over or underestimate prevalence and severity of glaucoma in the population. Diagnoses could have been misclassified through false positive or false negative diagnoses. This includes assessing the severity of glaucoma. Residual confounding is possible due to the observational nature of the study.

Prevalence of glaucoma and POAG persisted in the 2019 California Medicare beneficiaries primarily in older and female beneficiaries who identified as Black or Asian. The researchers said that this report suggests that rates of undiagnosed glaucoma should be investigated. Strategies to improve access to care for glaucoma, due to the prevalence of moderate to severe stages of glaucoma being so high, should be developed in the future.

Reference

Tseng VL, Kitayama K, Yu F, Coleman AL. Prevalence and severity of glaucoma in the California Medicare population. Am J Ophthalmol. Published online October 25, 2023. doi:10.1016/j.ajo.2023.10.018