Prevalence of glaucoma in the Northern Finland Birth Cohort Eye Study

Abstract

Purpose: To report the prevalence of glaucoma in the Northern Finland Birth Cohort (NFBC) Eye Study. Methods: Subjects of the population-based Northern Finland 1966 Birth Cohort (NFBC), aged 45–49 years at the time of the field examination, were randomized to eye screening (50%) and control (50%) groups. The eye examination protocol included best corrected visual acuity (BCVA), measurements of intraocular pressure and central corneal thickness, Humphrey 24-2 perimetry, stereoscopic optic nerve head (ONH) and retinal nerve fibre layer (RNFL) photography and imaging with optical coherence tomography (OCT), scanning laser polarimetry (GDx) and scanning laser ophthalmoscopy (HRT). The diagnosis of glaucoma was made by two independent general ophthalmologists and three independent glaucoma experts based on the evaluation of the ONH and RNFL photographs and the visual fields. Results: Totally, 10 321 subjects of the NFBC main study were alive in Finland in 2011, and they were randomized to the NFBC Eye Study group (n = 5155) and the control group (n = 5166). Of the randomized subjects, 3039 of 5155 (59%) responded and had sufficient data for the study. Glaucoma was suspected in 172 subjects (5.7%) at the first phase of the evaluation protocol. The interobserver agreement between two screening ophthalmologists was moderately good (kappa value 0.54 [95% confidence intervals (CI) 0.46–0.61]). Finally, definite glaucoma was found in 33 subjects (1.1% [95% CI 0.8–1.5]). Conclusion: The study provides up-to-date information on the prevalence of glaucoma in a middle-aged Caucasian population in Finland. The baseline data reported here allows the evaluation of the cost-effectiveness of screening later on.