Determinants of primary open-angle glaucoma

PURPOSETo create a quantitative basis for diagnostic criteria for primary open-angle glaucoma (POAG), and to propose an epidemiologic definition for POAG based on these, and to determine the prevalence of POAG in a general white population. METHODSOf the 7,983 subjects 55 years of age or older participating in the population-based Rotterdam Study, 6,756 subjects participated in the ophthalmic part of this study (6,281 independently living subjects and 475 in nursing homes). The criteria for the diagnosis of POAG were based on ophthalmic and semi-automated Imagenet estimations of the optic disc such as vertical cup-to-disc ratio (VCDR), minimal width of neural rim, or asymmetry in VCDR between both eyes, and visual field testing with kinetic Goldmann perimetry. All criteria for the diagnosis of POAG were assessed in a masked way independently of each other. RESULTSMean VCDR on ophthalmoscopy was 0.3 and with Imagenet 0.49, and the 97.5th percentile for both was 0.7. The prevalence of glaucomatous visual field defects was 1.5%. Overall prevalence of definite POAG in the independently living subjects was 0.8% (95% confidence interval [CI] 0.6, 1.0; 50 cases). Prevalence of POAG was double that in women (odds ratio 2.1, 95% CI 1.2, 3.6). Different commonly used criteria for diagnosis of POAG resulted in prevalence figures ranging from 0.1% to 1.2o/o. CONCLUSI00JThe overall prevalence of POAG in the present study was comparable to most population-based studies. However, prevalence figures differed by a factor of 12 when their criteria for POAG were applied to this population. ll. definition for definite POll.G is proposed: a glaucomatous optic neuropathy in eyes with open angles in the absence of history or signs of secondary glaucoma characterized by glaucomatous changes based on the 97.5 percentile for this population, together with glaucomatous visual field loss. In the absence of the latter or of a visual field test, it is proposed to