Exploring ethnic and racial differences in intraocular pressure and glaucoma: The Canadian Longitudinal Study on aging.

PURPOSE: To determine whether self-reported race/ethnicity is associated with intraocular pressure (IOP) and glaucoma and to explore whether any associations are due to social, behavioral, genetic, or health differences.

DESIGN: Cross-sectional analysis of population-based data.

METHODS: We used the Canadian Longitudinal Study on Aging Comprehensive Cohort, which consists of 30,097 adults aged 45-85 years. Race/ethnicity was self-reported. Corneal-compensated intraocular pressure (IOP) was measured in mmHg using the Reichert Ocular Response Analyzer. Participants were asked to report if they have ever had a diagnosis of glaucoma and whether they used eye care in the past year. A glaucoma polygenic risk score (PRS) was calculated. Logistic and linear regression models were used.

RESULTS: Black individuals had higher mean IOP levels (beta coefficient (β) = 1.46; 95% confidence interval [CI], 0.62, 2.30) while Chinese, Japanese and Korean (β = -1.00; 95% CI, -1.63, -0.38) and Southeast Asian and Filipino individuals (β = -1.56; 95% CI, -2.68, -0.43) had lower mean IOP levels as compared to White individuals after adjustment for sociodemographic, behavioral, genetic, and health-related variables. Black people were more likely to report glaucoma as compared to White people after adjustment (odds ratio [OR] = 2.43; 95% CI, 1.27, 4.64).

CONCLUSION: Racial and ethnic differences in IOP and glaucoma were identified. Adjusting for sociodemographic, behavioral, genetic, and health-related variables did not fully explain these differences. Longitudinal research is needed to further explore the reasons for these differences and to understand their relevance to disease pathogenesis and progression.