title: Prevalence and risk factors of pterygium and pinguecula: the Tehran Eye Study.
abstract: OBJECTIVE
  To determine the prevalence and causes of pterygium and pinguecula in the population of Tehran in 2002.
  
  
  METHODS
  In a cross-sectional population study with cluster sampling, 6497 residents of Tehran were selected from 160 clusters. Samples were chosen according to a door-to-door head counting and were then invited for free examinations. After the interview, ophthalmic examinations were performed at an eye clinic.
  
  
  RESULTS
  Of the selected sample, 4564 people (70.3%) participated in the study. The age- and gender-standardized prevalence of pterygium in this population was 1.3% (95% confidence interval (CI): 0.9-1.6%). The prevalence of pterygium was 1.4 and 1.1% in men and women, respectively (P>0.05). The prevalence of pinguecula in this study was 22.5% (95% CI: 21.1-24.0%); 27.1% in men and 17.7% in women (P<0.001). In both genders, the prevalence of pterygium and pinguecula showed a significant increase with age (P<0.001).
  
  
  CONCLUSIONS
  This study concerns the status of pterygium and pinguecula according to age and gender in the population of Tehran. The overall prevalence rates were 1.3 and 22.5% for pterygium and pinguecula, respectively. The comparison of the results with those reported from other areas of the world suggests lower prevalence rates in Tehran.
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran. afotouhi@tums.ac.ir
authors.forename: A
authors.initials: A
authors.lastname: Fotouhi
authors.forename: H
authors.initials: H
authors.lastname: Hashemi
authors.forename: M
authors.initials: M
authors.lastname: Khabazkhoob
authors.forename: K
authors.initials: K
authors.lastname: Mohammad
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D002648:Child; D002675:Child, Preschool; D016000:Cluster Analysis; D003229:Conjunctival Diseases / Q000453:epidemiology*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007223:Infant; D007492:Iran / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011625:Pterygium / Q000453:epidemiology*; D012307:Risk Factors; D017678:Sex Distribution; D055815:Young Adult