Rationale, methods and baseline demographics of the Bhaktapur Glaucoma Study

Background: To describe the methodology and baseline data of a population-based study designed to determine the prevalence of glaucoma and to study the risk factors for glaucoma development in a Nepali population. Design: Population-based cross-sectional study Participants: Subjects 40years and above residing in Bhaktapur District. Patients and Methods: Power calculations suggest that a sample size of 4758 is required. Thirty clusters were randomly selected from the 2 municipalities and 16 Village Development Committees of Bhaktapur District in Nepal. A door-to-door census was conducted in the selected clusters to identify citizens 40years of age and older. Demographic details were collected and a structured interview, regarding awareness for cataract and glaucoma was taken. All individuals fulfilling the eligibility criteria were recruited and referred to the Tilganga Institute of Ophthalmology in Kathmandu for a detailed clinical examination including glaucoma diagnostic procedures. Peripheral blood samples were taken to facilitate future genetic analysis. Main Outcome Measures: Prevalence of glaucoma, risk factors and genetic screening. Results: A total of 4800 people were selected. The mean age of participants was 55.4±12.3years (range: 40-99) and 51.8% were female. In total, 64.8% of our cohort was aged less than 59years and 60.5% were illiterate. Among the various ethnic races, 69.7% belonged to the Newar ethnic group. Conclusion: This study will determine the prevalence of glaucoma and allow for an increased understanding of the risk factors for glaucoma development in this region.