Abstract
Purpose: :
Keratoconus has a well-documented association with Floppy Eyelid Syndrome (FES). FES has been closely linked to sleep apnea. The current prevalence of sleep apnea in keratoconus patients is unknown. The purpose of this project is to determine the risk of sleep apnea in the keratoconus population.
Methods: :
The Berlin Questionnaire is an accepted survey tool used to characterize sleep apnea risk. The questionnaire includes specific questions about snoring habits, observed apneas, daytime sleepiness, and relevant co-morbidities. 74 keratoconus patients and 110 control patients from the same population were administered this survey via telephone and verbally in clinic, respectively. New clinic patients were used as controls. The questionnaire categorizes the patient’s risk for sleep apnea as high or low. Chi-squared tests were used to compare the two groups, and a multivariate logistic regression analysis was performed with co-variates of keratoconus status, sex, and age.
Results: :
High risk patients were combined with patients with a known diagnosis of sleep apnea to calculate the prevalence of sleep apnea. Out of the 74 keratoconus patients, 9 (12%) had a positive known history for sleep apnea, and 18 (24%) were categorized to be high risk by the Berlin Questionnaire. Out of the 110 control patients, 8 (7.3%) had a positive known history for sleep apnea, and 31 (28.2%) were categorized to be high risk by the Berlin Questionnaire. Although keratoconus patients had a higher prevalence of sleep apnea (36.5%) than controls (35.5%), there was no statistically significant difference (p=.939). BMI was significantly higher among keratoconus patients (p=.023) which is a major risk factor for sleep apnea. Multivariate analysis showed no significant co-variate predictors in determining high risk for sleep apnea.
Conclusions: :
These results suggest a need for a larger sample size in order to elucidate a statistically significant difference or to conclusively determine non-association. Due to the serious health risks and early mortality associated with undiagnosed sleep apnea, it is important to expand this study to determine if keratoconus patients should be screened for sleep apnea.
Keywords: keratoconus • clinical (human) or epidemiologic studies: risk factor assessment • cornea: clinical science