Asthma and Keratoconus: An analysis of the risk factors association with the severity of keratoconus

Abstract Background: A cross-sectional study was undertaken in Australia to explore a wide range of risk factors associated with keratoconus. A questionnaire addressing age, gender, educational background, ocular and medical history, smoking and alcohol consumption, and physical examination comprising anthropometric measurements was collected; eye examination was undertaken. The associations between a range of risk factors and keratoconus was determined using univariate and multivariable linear regression analyses.Main Text: A total of 260 keratoconus subjects were included in this study. Mean age of subject was 35.5 (SD= 14.8) years and the majority of the subjects were European 171 (68.2%). Initial univariate regression analysis identified the following risk factors at the p<0.1 level with keratoconus: higher body mass index, smoking cigarettes, diabetes, rheumatoid arthritis and asthma were associated with increased severity of keratoconus, whereas eczema was associated with less severe keratoconus. Following multivariable regression analysis, only asthma remained as a significant risk factor associated with 2.2 diopters (D) steeper average mean keratometry compared to keratoconus subjects having no asthma [p = 0.03; β= 2.18; 95% confidence intervals: 1.22, 4.14].Conclusion: Our study describes the comprehensive assessment of all the known risk factors in a large keratoconus cohort recruited in Australia. Our study has reported asthma as the only risk factor found to be significantly associated with keratoconus. The results of this study allow us to better understand the aetiology of keratoconus and such a knowledge could be useful in instigate systemic management of patients to slow or prevent keratoconus.