title: Prevalence and associated factors of keratoconus in Jerusalem: a cross-sectional study.
abstract: OBJECTIVE
  To determine the prevalence and associated factors for keratoconus in a college student population sample in Jerusalem.
  
  
  METHODS
  Volunteers participated in this cross-sectional study. Videokeratography was performed on both eyes of each subject who also completed an anonymous questionnaire. Keratoconus was defined by cone apex ≥ 50D, inferior-superior dioptric difference ≥ 3.5 diopters, as well as positive results from the software indices KISA, KCI and KSI. The association between independent predictors and keratoconus was analyzed using multivariate logistic regression analysis.
  
  
  RESULTS
  Of a total of 987 volunteers, 981 (mean age 24.4) were included. The prevalence of keratoconus among all subjects was 2.34% (95% confidence interval [CI] 1.4-3.3). It was significantly higher in men (4.91%, CI 2.6-7.3) than women (1.07%, CI 0.3-1.9) but not between Israeli Arabs (3.0%, CI 0.6-5.4) and Israeli Jews (2.2%, CI 1.2-3.3). Keratoconus was significantly associated with positive family history of the disease (Odds Ratio [OR] 17.1, CI 5.0-57.8, P<0.001), male gender (OR 5.4, CI 2.1-14.3, P=0.001) and atopy (OR 3.0, CI 1.2-7.6, P=0.02), but not with eye rubbing.
  
  
  CONCLUSIONS
  The prevalence of keratoconus in Jerusalem was found to be much higher than that seen in other parts of the world, except India. This may be related to a combination of genetic and environmental factors. Positive family history, male gender and atopy were shown to be significant predictors. The results of this study signal a need for public health outreach and intervention for keratoconus.
authors.affiliation: School of Optometry and Vision Sciences, Cardiff University, Cardiff, UK. millodot@btinternet.com
authors.forename: Michel
authors.initials: M
authors.lastname: Millodot
authors.forename: Einat
authors.initials: E
authors.lastname: Shneor
authors.forename: Sophie
authors.initials: S
authors.lastname: Albou
authors.forename: Esther
authors.initials: E
authors.lastname: Atlani
authors.forename: Ariela
authors.initials: A
authors.lastname: Gordon-Shaag
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D018912:Arabs / Q000208:ethnology; D019781:Corneal Topography; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007557:Israel / Q000453:epidemiology; D007585:Jews / Q000208:ethnology; D007640:Keratoconus / Q000175:diagnosis / Q000208:ethnology*; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012307:Risk Factors; D017678:Sex Distribution; D011795:Surveys and Questionnaires; D055815:Young Adult