Studies on the Epidemiology of Open-angle Glaucoma

University dissertation from Uppsala : Acta Universitatis Upsaliensis

Abstract: Glaucoma is a common disease in the elderly population. Open-angle glaucoma (OAG) is the predominant form of glaucoma. Chronic simple glaucoma and capsular glaucoma, characterized by the occurrence of pseudoexfoliation in the anterior eye segment, are the most frequent types of OAG. The purpose of the present thesis was to study the epidemiology of OAG in the municipality of Tierp, whose population has a high exposure to pseudoexfoliation.In a case-finding study, the prevalence of known cases of OAG by December 31, 1983 was estimated to 1.4% in people ?45 years of age. Sixty-three percent of all cases had capsular glaucoma. Patients with advanced glaucoma were older, had had the disease for longer, had higher mean initial intraocular pressure, and had more extensive visual field defects at the time of diagnosis.A population survey of people 65–74 years of age was conducted in 1984–86. The prevalence of OAG was 5.3%. Pseudoexfoliation was found in 17%, being more common in females. Pseudoexfoliation was associated with OAG only in people previously diagnosed with the disease (odds ratio = 16). In cases detected at the survey, an intraocular pressure ?20 mmHg was a serious risk factor of having OAG (odds ratio = 9.7).In a 5-year follow-up study of participants in the population survey, increased intraocular pressure and pseudoexfoliation were recognized as independent risk factors for the development of OAG (standardized risk ratios = 3.4 and 9.8, respectively). Interaction between increased intraocular pressure and pseudoexfoliation was indicated. By May 2006, the incidence of OAG was estimated to 7.1 per 1,000 person-years. The incidence of capsular glaucoma was more than twice that of chronic simple glaucoma.The prevalence and incidence of OAG was higher than that reported from other studies conducted on Caucasian populations. The probable explanation for this finding is exposure to pseudoexfoliation.