Five-year incidence of primary glaucoma and related risk factors - The Handan eye study.

Purpose: To determine the 5-year incidence of primary glaucoma and its associated risk factors in rural northern China.

Methods: Population-based cohort study. A total of 5184 participants aged 30 years and older, without glaucoma at baseline, were subjected to comprehensive standardized interviews and ophthalmic and systemic examinations at baseline and after a 5-year interval in the Handan Eye Study. Incident glaucoma was diagnosed by a consensus panel of five senior glaucoma specialists. Univariate and multivariable logistic regression analyses were performed to identify the baseline risk factors that could predict the incidence of glaucoma.

Results: During the 5-year follow-up, incident primary glaucoma developed in 82 subjects (1.6%; 95% confidence interval [CI], 1.2%-1.9%). The age- and gender-standardized incidence of glaucoma among subjects ≥40 years old was 2.1% (0.4% annually), calculated according to the 2010 Chinese census. A higher age (odds ratio [OR], 1.06; 95% CI, 1.04-1.09; p < 0.001), higher intraocular pressure (IOP) (OR, 1.11; 95% CI, 1.02-1.20; p = 0.017), and vertical cup disc ratio (VCDR) ≥ 0.60 (OR, 5.30; 95% CI, 3.22-8.73; p < 0.001) were found to be associated with an increased risk of incident glaucoma. For each year, older age and each mmHg higher IOP, the risks of primary glaucoma increased by 1.2% and 2.0% per year, respectively.

Conclusion: We reported the 5-year incidence of primary glaucoma in a rural Chinese population and found that older age, higher IOP, and VCDR ≥ 0.60 at baseline could help in identifying those at highest risk of disease development.