title: Epidemiology of pterygium on a tropical island in the Riau Archipelago.
abstract: OBJECTIVE
  To describe the epidemiology of pterygium among residents of an island in Indonesia and to examine the roles of age and gender as determinants of bilaterality and severity of the disease.
  
  
  METHODS
  Voluntary eye screening on Pulau Jaloh, Riau Archipelago, Indonesia. Gender difference was tested using the chi2 test. The difference in age between subjects with and without disease was tested using unpaired Student's t-test. Odds ratio (relative risk) for gender was calculated using logistic regression model with adjustment for age.
  
  
  RESULTS
  Of the 550 inhabitants, 477 (86.7%) responded to the eye screening. The overall prevalence rate of pterygium was 17.0%. Out of 211, 48 male (22.7%) and 33 out of 266 female subjects (12.4%) had the disorder, with the gender difference being statistically significant. Adjusted for age, the risk of disease was 3.1-fold higher among the males. In all, 71.6% of subjects with pterygium had bilateral disease. Subjects with pterygium were significantly older, their mean age being 42.9 years compared to 18.7 years among those without disease. The prevalence rates in male subjects increased from age 20 to reach a plateau of 63.6% at age 35 and remained stable thereafter. In the female subjects, the rates also increased with age, albeit at a slower rate, from age 20 to reach a plateau of 46.7% at age 55 and remained stable thereafter.
  
  
  CONCLUSIONS
  There is a high prevalence rate of pterygium among the study subjects, with the rates increasing rapidly with age.
authors.affiliation: The Eye Institute at Tan Tock Seng Hospital, National Healthcare Group, Singapore. Colintan_eye@yahoo.com.sg
authors.forename: C S H
authors.initials: CS
authors.lastname: Tan
authors.forename: T H
authors.initials: TH
authors.lastname: Lim
authors.forename: W P
authors.initials: WP
authors.lastname: Koh
authors.forename: G C
authors.initials: GC
authors.lastname: Liew
authors.forename: S T
authors.initials: ST
authors.lastname: Hoh
authors.forename: C C
authors.initials: CC
authors.lastname: Tan
authors.forename: K G
authors.initials: KG
authors.lastname: Au Eong
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007214:Indonesia / Q000453:epidemiology; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D015995:Prevalence; D011625:Pterygium / Q000453:epidemiology*; D017678:Sex Distribution