Purpose: To determine the prevalence of glaucoma according to the International Society for Geographical and Epidemiological Ophthalmology (ISGEO) classification in an adult German cohort.
Methods: The Gutenberg Health Study is a population-based, prospective cohort study in the Rhine-Main Region in mid-western Germany with a total of 15,010 participants. In this study, the first 5000 subjects with an age range between 35 and 74 years were included. Optic disk pictures were obtained by a non-mydriatic fundus camera (Visucam™) and analyzed using the Visupac™ software. Glaucoma prevalence was determined in two steps. First, the ISGEO classification was applied using "hypernormal subjects" (normal visual field) as reference. In the second analysis, we additionally considered the disk area (DA) in relation to the vertical cup-to-disk ratio by quantile regression. All results are given as weighted numbers for the population of Mainz/Bingen.
Results: The prevalence of definite glaucoma in our sample was 1.44% (n = 72). The prevalence adjusted for disk area was 1.34% (n = 67). The prevalence gradually increased in both models with each decade of age (from 0.9 to 2.4%, respectively). In both models, none of the glaucoma cases had a small optic disk (< 1.6 mm2). Glaucoma prevalence in medium optic disks was 1.0% (without DA adjustment) vs. 1.6% (with DA adjustment) and in large optic disks 5.6 vs. 2.5%.
Conclusions: The prevalence of definite glaucoma was similar to other European population-based cohorts, with slightly higher prevalence in younger subjects. Our analysis highlighted the influence of optic disk size in determining the diagnosis of glaucoma based on cup-to-disk ratio in epidemiological studies.
Keywords: Glaucoma; Gutenberg Health Study; ISGEO; Population-based cohort; Prevalence.