title: Population-based assessment of prevalence and risk factors for pterygium in the South Indian state of Andhra Pradesh: the Andhra Pradesh Eye Disease Study.
abstract: OBJECTIVE
  To describe the prevalence and risk factors for pterygium in a population-based sample of individuals aged 30 years and older in South Indian state of Andhra Pradesh.
  
  
  METHODS
  A cross-sectional study was conducted in one urban and three rural locations in which 10,293 subjects were examined. All the subjects underwent comprehensive eye examination and a detailed interview by trained professionals. Pterygium was defined as fleshy fibro vascular growth, crossing the limbus, and typically seen on the nasal conjunctiva in either eye.
  
  
  RESULTS
  Data were analyzed for 5586 subjects who were aged 30 years and older at the time of participation. The mean age of the participants was 47.5 years (SD 13 years; range 30-102 years). In total, 46.4% were male, 56.7% had no education, 52.2% of them were involved in outdoor occupations, and 25% belonged to urban area. The prevalence of pterygium was 11.7% (95% confidence interval [CI]: 10.9-12.6). The multiple logistic regression analysis revealed significantly higher odds of pterygium among older age groups, rural residents (odds ratio [OR]: 1.8; 95% CI: 1.4-2.4; P > 0.01), and those involved in outdoor occupations (OR: 1.8; 95% CI: 1.5-2.2, P < 0.001). Education had a protective effect (OR: 0.6; 95% CI: 0.5-0.7; P < 0.001).
  
  
  CONCLUSIONS
  Pterygium is common in the South Indian state of Andhra Pradesh. Exposure to sunlight is a significant modifiable risk factor. Protecting the eyes from sunlight may decrease the risk of pterygium. However, the important public health challenge is to encourage the use of this protection as a routine in developing countries such as India.
authors.affiliation: Allen Foster Community Eye Health Research Centre, International Centre for Advancement of Rural Eye Care, L V Prasad Eye Institute, Hyderabad, India. srioptom@lvpei.org
authors.forename: Srinivas
authors.initials: S
authors.lastname: Marmamula
authors.forename: Rohit C
authors.initials: RC
authors.lastname: Khanna
authors.forename: Gullapalli N
authors.initials: GN
authors.lastname: Rao
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D003906:Developing Countries; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007194:India / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D011159:Population Surveillance; D015995:Prevalence; D011625:Pterygium / Q000453:epidemiology*; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D012424:Rural Population; D017678:Sex Distribution; D014505:Urban Population
keywords: Andhra Pradesh; India; outdoor occupations; pterygium; risk factors