Association Between Myopia and Primary Open-Angle Glaucoma by Race and Ethnicity in Older Adults in the California Medicare Population.

IMPORTANCE: Racial and ethnic differences in the association between myopia and primary open-angle glaucoma (POAG) are not well understood.

OBJECTIVE: To investigate the association between myopia and POAG in the 2019 California Medicare population and to investigate whether there was evidence of effect measure modification of this association by race and ethnicity.

DESIGN, SETTING, AND PARTICIPANTS: This cross-sectional study used administrative claims data from 2019 California Medicare beneficiaries 65 years or older with California residence and active coverage with Medicare parts A and B. Analysis took place between October 2021 and October 2023.

EXPOSURES: The primary exposure was myopia, which was defined by International Statistical Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM) diagnosis codes.

MAIN OUTCOMES AND MEASURES: The outcome of interest was POAG, which was defined by ICD-10-CM code.

RESULTS: Of 2 717 346 California Medicare beneficiaries in 2019, 1 440 769 (53.0%) were aged 65 to 74 years, 1 544 479 (56.8%) identified as female, 60 211 (2.2%) had myopia, and 171 988 (6.3%) had POAG. Overall, 346 723 individuals (12.8%) identified as Asian, 117 856 (4.3%) as Black, 430 597 (15.8%) as Hispanic, 1 705 807 (62.8%) as White, and 115 363 (4.2%) as other race and ethnicity. In adjusted logistic regression analyses, beneficiaries with myopia had higher odds of POAG compared with beneficiaries without myopia (odds ratio [OR], 2.41; 95% CI, 2.35-2.47). In multivariable models stratified by race and ethnicity, the association between myopia and POAG was stronger in Asian (OR, 2.74; 95% CI, 2.57-2.92), Black (OR, 2.60; 95% CI, 2.31-2.94), and Hispanic (OR, 3.28; 95% CI, 3.08-3.48) beneficiaries compared with non-Hispanic White beneficiaries (OR, 2.14; 95% CI, 2.08-2.21).

CONCLUSIONS AND RELEVANCE: In the 2019 California Medicare population, myopia was associated with greater adjusted odds of POAG. This association was stronger among Asian, Black, and Hispanic beneficiaries compared with non-Hispanic White beneficiaries. These findings suggest possible disparities in glaucoma risk by race and ethnicity in individuals with myopia and may indicate greater need for glaucoma screening in individuals with myopia from racial and ethnic minority backgrounds.