Long-term effects of PAP on ocular surface in obstructive sleep apnea syndrome

Objective: To assess the long-term effects of positive airway pressure (PAP) therapy on the ocular surface and eyelid in patients with obstructive sleep apnea hypopnea syndrome (OSAHS). Design: Single-centred, prospective, and double-blinded study. Participants: Fifty-one patients with OSAHS. Methods: Fifty-one patients with OSAHS were treated with PAP for a period of 18 months. The pre- and post-PAP values for eye examination scores (presence of floppy eyelid syndrome [FES], results of the Ocular Surface Disease Index [OSDI] questionnaire, Schirmer I test, tear film break-up time [TBUT] values, and corneal staining stages) were compared. Results: Based on the apnea-hypopnea index, 17 patients were followed with moderate and 34 patients were followed with severe OSAHS. The presence of FES before and after PAP was 56.9% and 74.5% (p < 0.01). FES stage was determined as 1.41 +/- 0.98 before PAP and 0.78 +/- 0.78 after PAP (p < 0.01). Pre-PAP and post-PAP OSDI results were 47.79 +/- 21.04 and 42.17 +/- 19.97, respectively (p < 0.01). Schirmer values before and after PAP were 7.23 +/- 1.95 and 8.49 +/- 1.79 mm, respectively (p < 0.01). TBUT values before and after PAP were 7.11 +/- 1.82 and 8.68 +/- 1.76 seconds, respectively (p < 0.01). Scores of the corneal staining stages before and after PAP were 1.05 +/- 0.75 and 0.68 +/- 0.54, respectively (p < 0.01). Conclusions: OSAHS is associated with low Schirmer and TBUT values, and high scores in OSDI questionnaire, and high corneal staining stage. An appropriate PAP therapy helps to relieve both the systemic findings and the ocular surface problems most likely by providing a return to normal sleep patterns. We believe that long-term (at least 1 year) use of PAP improves the clinical picture of FES and can overcome the problem of ocular irritation that is encountered in the early stage of PAP.