Alterations of Ocular Surface and Tear Film in Patients with Obstructive Sleep Apnea/Hypopnea Syndrome

Purpose: Obstructive sleep apnea/hypopnea syndrome (OSA) results in repeated oxygen desaturation, repeated arousals, and episodic nocturnal activation of sympathetic nervous system during sleep. Untreated OSA is strongly associated with an increase of cardio- and cerebrovascular disorders, as well as the damages of ophthalmological microstructures. However, previous literature only simply studied the association between the ophthalmic disorders and OSA. In the present study, we first investigated the alterations of ocular surface and tear film non-invasively with the innovated corneal topographer in untreated OSA patients and normal control subjects. Furthermore, we analyzed in depth whether the correlations between OSA severity and ocular surface exams exist.

Participants and methods: Participants underwent a full-night polysomnography to determine OSA occurrence and severity. All participants subsequently received Ocular Surface Disease Index questionnaire and comprehensive ocular exams, including floppy eyelid syndrome (FES) assessment, oculus scan for tear meniscus height, non-invasive keratograph tear film breakup time (NIKBUT), and ocular surface redness, endothelial cell density, and corneal fluorescein staining.

Results: One hundred eighty-one participants were prospectively enrolled in the study. FES was found in 11.5% of the normal control group and 60.0% of the severe OSA group (p=0.0005). There were significant differences in the first-NIKBUT (F-NIKBUT) (p < 0.0001), average-NIKBUT (A-NIKBUT) (p = 0.0007), and redness scores over the nasal bulbar (p = 0.032), temporal bulbar (p < 0.0001), nasal limbal (p = 0.014), and temporal limbal (p < 0.0001) areas among the four groups. F-NIKBUT and A-NIKBUT were significantly shorter in the moderate/severe OSA group (apnea/hypopnea index (AHI) ≥15) than in the normal/mild OSA group (AHI <15) (both p < 0.0001). The redness scores over the temporal bulbar (p < 0.0001) and temporal limbal (p < 0.0001) areas were also significantly different in these two OSA groups. Moreover, F-NIKBUT and A-NIKBUT negatively correlated with AHI. Nasal bulbar redness, temporal bulbar redness, nasal limbal redness, and temporal limbal redness positively correlated with AHI.

Conclusion: OSA patients had higher occurrence of FES. The NIKBUT was significantly shorter, and the temporal conjunctival redness scores over bulbar and limbal areas were higher in the moderate/severe OSA group than in the normal/mild OSA group. NIKBUT and conjunctival hyperemia significantly correlated with the severity of untreated OSA.