Prevalence and associated factors of keratoconus in Jerusalem: a cross-sectional study

Abstract

Purpose: 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.