Abstract
Purpose: :
Keratoconus is a progressive non inflammatory corneal ectasia. The cause of this condition is unknown. A positive association between keratoconus and many conditions has been suggested, including eye rubbing, atopy, floppy eyelid syndrome (FES) and obstructive sleep apnea syndrome (OSAS). A few investigations have raised the question of a possible relationship between keratoconus and these four conditions.
Methods: :
A prospective case-control study was performed in Strasbourg University Hospitals (France) between 2010 and 2011. The keratoconus subpopulation (57 cases) was compared with a sample control of non-keratoconus subjects paired on age, sex and Body Mass Index. All patients underwent overnight ambulatory respiratory polygraphy, comprehensive ophthalmological examination, completed standard sleep questionnaires and were screenned for OSAS using the Epworth daytime somnolence score. OSAS severity was defined based on the patient's obstructive apnea-hypopnea index (AHI). Univariate analysis and a multivariate logistic model using a logistic regression were performed to determine relative risks.
Results: :
The keratoconic sample reported a significantly higher level of FES (61%)(p=0.001), eye rubbing (79%) (p=0.001) and atopy (46%) (p=0.001) as compared to control group. There were no significant correlation between OSAS (AHI>5) and keratoconus (p=0.297). A linear regression model allowed us to determine keratoconus predictive factors with a sensitivity of 84.2% and a specificity of 93%.
Conclusions: :
This study permit to establish a link between eye rubbing, atopy, floppy eyelid syndrome, obstructive sleep apnea syndrome and keratoconus.
Keywords: keratoconus • clinical (human) or epidemiologic studies: risk factor assessment • computational modeling