Effect of Continuous Positive Airway Pressure on Intraocular Pressure in Patients With Obstructive Sleep Apnoea: A Systematic Review and Meta-Analysis

Abstract

Background: While the association between obstructive sleep apnoea (OSA) and glaucoma has been well studied, the long-term effects of continuous positive airway pressure (CPAP) therapy on intraocular pressure (IOP) and glaucoma progression are less known. This study aims to systematically synthesise evidence to clarify the association between CPAP therapy and IOP. Methods: PubMed, Embase, The Cochrane Library, CINAHL, Scopus and Web of Science were searched through 26 March 2025 for interventional studies evaluating the effect of CPAP therapy on IOP among OSA adult patients. Two independent authors selected relevant articles, extracted data and evaluated the quality of evidence using the Newcastle–Ottawa scale (NOS), Cochrane Risk-of-Bias Tool for Randomised Trials (RoB 2) and Grading of Recommendations Assessment, Development and Evaluation (GRADE). Inverse variance meta-analyses were conducted using random effects. I² values were used to evaluate heterogeneity. Results: This study included 16 studies, pooling a cohort of 602 patients. The risk of bias of studies ranged from low to moderate, and the quality of evidence was moderate on GRADE. CPAP therapy significantly increased IOP levels overnight (MD: −4.14; 95% CI: −7.76, −0.52; I² = 76%; p = 0.04), and within 1 month (MD: −0.78; 95% CI: −1.21, −0.35; I² = 0%; p = 0.60). IOP levels remained unchanged with CPAP therapy of more than 1 month from baseline. Conclusions: While short-term CPAP therapy of 1 month or less in OSA patients was associated with elevated IOP, minimal long-term effects were observed. Nonetheless, these findings underscore the importance of exercising caution when administering CPAP therapy on IOP especially in glaucomatous patients.