The impact of obstructive sleep apnea syndrome on corneal sensitivity and dry eye parameters: a comprehensive...

Obstructive Sleep Apnea Syndrome (OSAS) is a common sleep disorder involving recurrent upper airway obstruction during sleep, leading to intermittent hypoxia, oxidative stress, and systemic inflammation. Although OSAS has been linked to several ocular disorders, its specific impact on ocular surface health, particularly in relation to dry eye disease (DED) and corneal sensitivity, is not fully understood. This study aimed to assess how OSAS severity influences dry eye parameters and corneal sensitivity, and to explore associations with systemic and demographic factors.

In this cross-sectional study, 174 patients diagnosed with OSAS via overnight polysomnography were divided into normal-mild OSAS and moderate-severe OSAS groups. Ocular surface assessments included non-invasive tear break-up time (NIBUT), Schirmer II test (ST), Ocular Surface Disease Index (OSDI), and corneal sensitivity measured in five corneal regions using a Cochet-Bonnet esthesiometer. Statistical analyses involved group comparisons, correlation assessments, and multivariable linear regression to identify predictors of dry eye parameters.

Moderate-severe OSAS (AHI ≥ 15; n = 85) patients were older, had higher BMI, and lower minimum oxygen saturation (p < 0.001). No significant differences were observed between groups in NIBUT, ST, or regional corneal sensitivity. Interestingly, OSDI scores were lower in the moderate-severe group, nearing statistical significance (p = 0.055). ST was positively correlated with corneal sensitivity (r = 0.22-0.26), whereas OSDI was negatively correlated (r =  - 0.14- - 0.18). Regression analyses identified age and smoking as significant predictors of NIBUT, and gender and oxygen saturation as predictors of OSDI.

Although OSAS severity did not significantly affect objective dry eye measures or corneal sensitivity, subtle associations between tear production and corneal nerve function suggest possible subclinical ocular changes. Routine eye evaluations may benefit OSAS patients, especially those with risk factors like aging, smoking, and hypoxemia.