The incidence of open-angle glaucoma in a general elderly population: The Rotterdam Study

Purpose: To determine the incidence of open–angle glaucoma (OAG) in a general elderly Caucasian population. Methods: Participants (n=3842) of the prospective population–based Rotterdam Study, aged 55 years and older and at risk for incident OAG, underwent at baseline and follow–up the same ophthalmic examination including measurement of intra–ocular pressure, visual field testing and stereo optic disc photography. The diagnosis of probable or definite OAG was made with an algorithm based on optic disc parameters and on glaucomatous visual field loss, independent of the intra–ocular pressure. The incidence was calculated in incidence rates and 5–year risks. Results:After a mean follow–up time of 6.5 years, probable or definite OAG developed in 87 persons. The 5–year risk rose threefold till 3.2% in men between ages 55 and 80 years and one and a half times till 2.3% in women. The odds ratio for men versus women was 1.3 (95% confidence interval: 0.9–2.0) Bilateral OAG occurred five times more often after than before age 75. In participants with prevalent OAG in one eye, the 5–year risk of OAG in the fellow eye was five times higher than in fellow eyes of non–OAG eyes. Only 37% of the incident cases received treatment for OAG. Conclusions:The incidence of OAG rose with age and more in men than in women. Bilateral incident OAG occurred more frequently among the eldest participants. The majority of the new cases was unaware of having OAG.