title: Prevalence of open-angle glaucoma in a rural south Indian population.
abstract: OBJECTIVE
  To determine the prevalence of primary open-angle glaucoma (POAG) and the associated risk factors in a rural population in southern India.
  
  
  METHODS
  Subjects aged 40 years or more (n = 3934) underwent a complete ophthalmic examination. Glaucoma was diagnosed according to the International Society of Geographical and Epidemiologic Ophthalmology classification.
  
  
  RESULTS
  Complete data were available for 3924 subjects (response rate, 81.75%). In eyes with normal suprathreshold visual fields, the mean intraocular pressure was 14.29 +/- 3.32 mm Hg (97.5th and 99.5th percentiles, 21 and 25 mm Hg, respectively). The mean vertical cup-to-disc ratio was 0.39 +/- 0.17 (97.5th and 99.5th percentiles, 0.7 and 0.8, respectively). Sixty-four subjects had definite POAG (1.62%, 9.5% CI 1.42-1.82); 30 were men and 34 were women. Subjects with POAG (59.85 +/- 10.43 years) were older (P < 0.001) than the study population (53.78 +/- 10.71 years). In only one (1.5%) person was POAG diagnosed before the study. Two (3.12%) subjects were blind due to POAG; 21 (32.81%) subjects had a presenting IOP >21 mm Hg, and 43 (67.19%) had an IOP <21 mm Hg. The mean central corneal thickness in subjects with POAG (502.82 +/- 35.29 microm) was not different from that of the normal study population (505.93 +/- 31.11 microm). No association was found with diabetes mellitus, systemic hypertension, gender, and myopia. Increasing IOP (per mm Hg) was associated with the disease (OR 1.12; 95% CI, 1.08-1.16). The odds for POAG increased with advancing age after adjustment for gender.
  
  
  CONCLUSIONS
  The prevalence of POAG in this population was 1.62%. The prevalence increased with age, and 98.5% were not aware of the disease.
authors.affiliation: Glaucoma Project, Vision Research Foundation, Sankara Nethralaya, Chennai, India.
authors.forename: Lingam
authors.initials: L
authors.lastname: Vijaya
authors.forename: Ronnie
authors.initials: R
authors.lastname: George
authors.forename: Pradeep G
authors.initials: PG
authors.lastname: Paul
authors.forename: Mani
authors.initials: M
authors.lastname: Baskaran
authors.forename: Hemamalini
authors.initials: H
authors.lastname: Arvind
authors.forename: Prema
authors.initials: P
authors.lastname: Raju
authors.forename: S Ve
authors.initials: SV
authors.lastname: Ramesh
authors.forename: Govindasamy
authors.initials: G
authors.lastname: Kumaramanickavel
authors.forename: Catherine
authors.initials: C
authors.lastname: McCarty
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D001766:Blindness / Q000453:epidemiology; D005260:Female; D005902:Glaucoma, Open-Angle / Q000453:epidemiology*; D006801:Humans; D007194:India / Q000453:epidemiology; D007429:Intraocular Pressure; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012307:Risk Factors; D012424:Rural Population / Q000706:statistics & numerical data*; D017678:Sex Distribution