Nine-Year Incidence of Open-Angle Glaucoma in the Barbados Eye Studies
Received 6 July 2006; accepted 29 August 2006. published online 31 March 2007.
Purpose
To determine the 9-year incidence of open-angle glaucoma (OAG) in African-descent participants of the Barbados Eye Studies.
Design
Nine-year cohort study with 81% to 85% participation.
Participants
Three thousand two hundred twenty-two persons without definite OAG at baseline, at risk of developing OAG at follow-up.
Methods
The standardized protocol included automated perimetry and various ophthalmic measurements, with a comprehensive ophthalmologic examination for those referred. Fundus photographs were evaluated independently by masked graders. Incidence was estimated by the product-limit approach. Relative risk (RR) ratios with 95% confidence intervals (CIs) were based on Cox regression models with discrete time.
Main Outcome Measure
Nine-year incidence of definite OAG, based on the development of visual field defects and glaucomatous optic neuropathy, with ophthalmologic confirmation.
Results
The 9-year incidence of definite OAG was 4.4% (95% CI, 3.7%–5.2%), or an average of 0.5%/year, based on 125 new cases. Incidence increased greatly with age, from 2.2% at ages 40 to 49 years to 7.9% at ages 70 years or older, and tended to be higher in men than women (4.9% vs. 4.1%; RR, 1.3; 95% CI, 0.9–1.8). More than half (53%) of new cases were undetected, and of these, one third had intraocular pressure of 21 mmHg or less. When 141 persons developing suspected/probable OAG were considered, the total incidence was 9.4% (8.4%–10.6%), averaging approximately 1%/year, also increasing with age, and significantly higher in men than women (10.7% vs. 8.6%; RR, 1.31; 95% CI, 1.02–1.67).
Conclusions
These new data provide a measure of the long-term risk of OAG in an African-descent population, which is markedly higher than in persons of European ancestry. Results confirm the increased risk with age and in men. The incidence data fill a gap in our understanding of OAG risk and have implications for public health policy and planning; they also will allow the study of factors related to the risk of OAG development.
1Department of Preventive Medicine, Stony Brook University, Stony Brook, New York.
2Department of Ophthalmology, Stony Brook University, Stony Brook, New York.
3Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland.
5Chronic Disease Research Centre, Tropical Medicine Research Institute, University of the West Indies, Bridgetown, Barbados.
Correspondence to M. Cristina Leske, Department of Preventive Medicine, Stony Brook University, L3 HSC Room 086, Stony Brook, NY 11794-8036.
Manuscript no. 2006-739.
Supported by the National Eye Institute, Bethesda, Maryland (grant nos. EY07625, EY07617).
⁎ For Group membership, see Leske MC, Wu SY, Hennis A, et al. Nine-year incidence of age-related macular degeneration in the Barbados Eye Studies. Ophthalmology 2006;113:29–35.
ABSTRACT