Corneal Topographic Changes and Intraocular Pressure in Different Stages of Obstructive Sleep Apnea: Case–Control Study

Abstract

Purpose: To evaluate corneal topographic parameters and intraocular pressure (IOP) in patients with different stages of obstructive sleep apnea (OSA) compared healthy controls, and to explore correlations between ocular findings and polysomnographic parameters. Patients and Methods: This case-control study included 55 patients diagnosed with obstructive sleep apnea (OSA) and 22 healthy controls. All participants were recruited immediately after diagnosis and prior to the initiation of any treatment. OSA diagnosis was confirmed by full-night diagnostic polysomnography. Control subjects were screened clinically and underwent polysomnography to confirm the absence of OSA. Ophthalmic assessments were performed within the same week of polysomnography assessment and included measurement of intraocular pressure using Goldmann applanation tonometry and anterior segment imaging using Scheimpflug-based corneal tomography. Corneal pachymetry, anterior chamber parameters, keratometric indices, and ectasia-related indices were recorded and analyzed. Results: No statistically significant differences were observed among groups regarding posterior corneal pachymetric parameters. Anterior chamber depth was significantly reduced in mild and severe OSA groups, and anterior chamber volume was lowest in the mild OSA group. Intraocular pressure was significantly higher in moderate and severe OSA groups compared with controls. Significant correlations were observed between arousal index and several corneal parameters, including pachymetry and progression indices. Conclusion: Moderate and severe OSA were associated with increased intraocular pressure and changes in anterior chamber configuration. Arousal index showed significant correlations with corneal pachymetric and topographic parameters, suggesting a possible association between sleep fragmentation and corneal structural changes. Further studies of larger sample sizes are recommended to confirm these findings.