title: Methods and design of the Chennai Glaucoma Study.
abstract: OBJECTIVE
  To describe the methodology of a population-based study to estimate the prevalence of glaucoma in a rural and urban South Indian population and to study the genetics of glaucoma in this population.
  
  
  METHODS
  A sample size of 4758 each for rural and urban populations in the Indian state of Tamil Nadu was calculated. Eligible subjects aged 40 years and above from the rural study area covering 32 contiguous villages and the urban area comprising five random clusters in Chennai city are enumerated. Demographic data are collected in the field. A detailed clinical examination, including glaucoma diagnostic procedures, is conducted at the examination centre. Pedigree ascertainment and genetic studies are performed for subjects with occludable angles or glaucoma. Data are recorded in a computerised database.
  
  
  CONCLUSIONS
  This study is expected to result in an estimation of the prevalence and a better understanding of the genetics of glaucoma in this region.
authors.affiliation: Glaucoma Project, Vision Research Foundation, Chennai, Sankara Nethralaya, India.
authors.forename: Hemamalini
authors.initials: H
authors.lastname: Arvind
authors.forename: Pradeep G
authors.initials: PG
authors.lastname: Paul
authors.forename: Prema
authors.initials: P
authors.lastname: Raju
authors.forename: M
authors.initials: M
authors.lastname: Baskaran
authors.forename: Ronnie
authors.initials: R
authors.lastname: George
authors.forename: Sukumar
authors.initials: S
authors.lastname: Balu
authors.forename: Sarangapani
authors.initials: S
authors.lastname: Sripriya
authors.forename: S Ve
authors.initials: SV
authors.lastname: Ramesh
authors.forename: Bickol N
authors.initials: BN
authors.lastname: Mukesh
authors.forename: Lingam
authors.initials: L
authors.lastname: Vijaya
authors.forename: Govindasamy
authors.initials: G
authors.lastname: Kumaramanickavel
authors.forename: Catherine
authors.initials: C
authors.lastname: McCarty
mesh_terms: D000328:Adult; D035843:Biomedical Research / Q000379:methods; D003430:Cross-Sectional Studies; D005260:Female; D005901:Glaucoma / Q000175:diagnosis / Q000453:epidemiology* / Q000235:genetics; D006801:Humans; D007194:India / Q000453:epidemiology; D008297:Male; D015995:Prevalence; D012107:Research Design; D012424:Rural Population / Q000706:statistics & numerical data*; D014505:Urban Population / Q000706:statistics & numerical data*