Purpose: Diabetes and hypertension are recognized risk factors for raised intraocular pressure (IOP). This report examines the longitudinal relationship of hypertension and diabetes to a 4-year IOP change in a black population with high prevalence of these conditions.
Design: Population-based cohort study of a simple random sample of residents of Barbados, West Indies, aged >/=40 years.
Participants: A total of 2996 persons without open-angle glaucoma or receiving IOP-lowering medication at baseline.
Methods: Participants underwent standardized examinations including applanation tonometry, measurement of blood pressure, and anthropometric indices; a detailed interview; various ocular measurements; and venipuncture for glycosylated hemoglobin (GHb). Diabetes was defined by self-reported physician diagnosis and hypertension by blood pressure >/=140/90 mmHg and/or treatment history.
Main outcome measures: The 4-year person-based IOP change between baseline and follow-up was defined as the more positive IOP difference in either eye.
Results: An IOP >21 mmHg at baseline was more likely in black and in mixed (black and white) participants (age-gender adjusted odds ratio [OR], 3.9 and 3.8, respectively) than in whites. Similarly, these groups had more hypertension (age-gender adjusted OR, 2.4 and 2.1, respectively) and diabetes (age-gender adjusted OR, 3.9 and 1.7, respectively) than did whites. Mean IOP in black participants increased by 2.5 (standard deviation, 3.9) mmHg over 4 years. Multiple regression analyses showed that baseline diabetes history and hypertension, as well as older age, elevated GHb, higher blood pressures, and lower baseline IOP were associated with a 4-year increase of IOP. The association between diabetes history/GHb and IOP increase became borderline/nonsignificant when persons who underwent cataract surgery during follow-up were excluded.
Conclusions: This report provides new data on the relationship of systemic factors to longitudinal increases in IOP in an African-origin population. Results highlight the increased risk of elevated IOP in populations with high prevalences of diabetes and hypertension.