Abstract
Objective Our goal was to evaluate upper eyelid laxity by digital distraction, with the aim to determine sleeping laterality and the likelihood of obstructive sleep apnoea (OSA), and correlate these findings with polysomnography (PSG). Design We conducted a prospective, single-centre multidisciplinary study in a large sleep and respiratory department and an ophthalmology department within a tertiary referral university teaching hospital. Methods Patients with known OSA were evaluated using techniques based on the Lateralising Eyelid Sleep Compression (LESC) study. Upper eyelid laxity was assessed by two masked investigators, and the eyelid side with greater laxity was regarded as indicative of that patient's sleeping laterality: 'investigator-detected sleeping laterality' (ID SL). Each patient was then asked about the laterality of his or her accustomed sleeping position: 'patient-reported sleeping laterality' (PR SL). PSG was conducted according to the standard protocol of the Department of Sleep and Respiratory Medicine (DSRM). 'Polysomnography-detected sleeping laterality' (PSG SL) permitted the extraction of sleep positional data by two masked sleep scientists. Results The reliability of the LESC technique for diagnosing ID SL was demonstrated to be statistically significant (p<0.01). Upper eyelid laxity was significantly greater on the patients' sleeping side (t=6.340, df=45, p<0.01, two-tailed). There was a significant correlation between PR SL and ID SL (r(s) =0.33). However, PSG SL did not correlate with sleeping laterality compared with both ID SL and PR SL. Conclusion This study confirms that there is a statistically significant correlation of sleeping laterality with increasing upper eyelid laxity in OSA. Counterintuitively, PSG SL correlated poorly with ID SL and PR SL. This may likely be explained by the technical limitations implicit in current PSG techniques.