Incidence and prevalence of pseudoexfoliations and open-angle glaucoma in northern Sweden:: II.: Results after 21 years of follow-up

Purpose: To prospectively evaluate the prevalence and incidence of pseudoexfoliation (PEX) syndrome and open-angle glaucoma (OAG) with and without PEX and to evaluate PEX as a risk factor for glaucoma in a population born in 1915 and living in the municipality of Skelleftea in northern Sweden. Methods: A randomized population study comprising 339 individuals. The cohort was followed for 21 years at 7 year intervals. The examination included tonometry, dilated slit-lamp biomicroscopy, optic disc evaluation and, if glaucoma was suspected, a visual field analysis. Results: The prevalence of PEX increased from 23% [95% confidence interval (CI): 20-26] at 66 years of age to 61% (CI 50-71) at 87 years. The annual incidence of PEX was 1.8% (CI 1.3-2.4). In the group of subjects with unilateral PEX, 55% converted to bilateral PEX during follow-up. The prevalence of OAG was 2.1% (CI 0.8-4.3%) at 66 years of age and 25% (CI 16-35) at 87 years. Of the glaucoma cases, 59% had PEX. There was no difference in incidence between the sexes. The annual incidence of PEX and OAG did not increase with time. The overall annual incidence of OAG was 0.9% (CI 0.6-1.3%) [0.5% (CI 0.2-0.9) without PEX and 2.1% (CI 1.2-3.3) with PEX]. PEX increased the risk of glaucoma four fold in both sexes. There was no significant difference in mortality between individuals with or without PEX. Conclusion: PEX syndrome and OAG are common in the north of Sweden. Prevalences increase with age. PEX increases the risk of glaucoma four fold. The consequences of this situation demand guidelines for handling patients with PEX, with or without other risk factors. In order to issue guidelines, more information is needed on the impact of the disease on the general health in the ageing population.