RISK-FACTORS FOR OPEN-ANGLE GLAUCOMA - THE BARBADOS EYE STUDY

Objective: To evaluate risk factors for open-angle glaucoma among black participants in the Barbados Eye Study. Design: Population-based study of demographic, medical, ocular, familial, and other factors possibly related to open-angle glaucoma. Setting and Participants: The Barbados Eye Study included 4709 Barbados residents identified by a simple random sample of Barbadian-born citizens, 40 to 84 years of age; participation was 84%. This report is based on the 4314 black participants examined at the study site; 302 (7%) met the Barbados Eye Study criteria for open-angle glaucoma. Data Collection: A standardized protocol included applanation tonometry, Humphrey perimetry, fundus photography, blood pressure, anthropometry, and an interview. An ophthalmologic examination was performed for participants who met specific criteria. Main Outcome Measures: Open-angle glaucoma was defined by the presence of both characteristic visual field defects and optic disc damage. Association of open-angle glaucoma with specific factors was evaluated in logistic regression analyses. Results: Age, male gender, high intraocular pressure, and family history of open-angle glaucoma were major risk factors; the latter association was stronger in men than women. Lean body mass and cataract history were the only other factors related to open-angle glaucoma. Although hypertension and diabetes were common in Barbados Eye Study participants, they were unrelated to the prevalence of open-angle glaucoma. However, associations were found with low diastolic blood pressure-intraocular pressure differences and low systolic and diastolic blood pressure/intraocular pressure ratios. Conclusions: In the Barbados Eye Study black population, persons most likely to have open-angle glaucoma were older men and had a family history of open-angle glaucoma, high intraocular pressure, lean body mass, and cataract history. These results suggest the importance of possible genetic or familial factors in open-angle glaucoma. The role of vascular risk factors is consistent with our finding of low blood pressure to intraocular pressure relationships, but the results could be explained by the high intraocular pressure in open-angle glaucoma.