A study conducted in Lithuania has found that hypoxia significantly influences the central corneal thickness (CCT) and endothelial cell density (ECD) in patients with obstructive sleep apnea (OSA). The researchers believe that knowledge of these corneal abnormalities from sleep disturbances and hypoxemia may help eye care practitioners and sleep specialists better communicate to mitigate ocular complications in patients with OSA.

To determine the corneal parameters in patients with OSA, the study evaluated the relationship between the severity of OSA, minimum peripheral capillary oxygen saturation and corneal morphological characteristics in 74 eyes of patients with OSA and 40 control eyes. The researchers divided patients with OSA into three groups according to the Apnea-Hypopnea Index (AHI).

While they found a statistically significant association between ECD and CCT values and hypoxia, the study was unable to report on the hexagonal cell percentage or cell variation coefficient changes due to OSA. The mean CCT and ECD values in OSA patients were lower than those of the control eyes. The researchers found a significant negative correlation between CCT and ECD and a weak positive correlation for minimum peripheral capillary oxygen saturation.

The researchers did note that because OSA is difficult to self-diagnose, patients are generally unaware of their condition, usually leading to a late diagnosis. This limited the study due to a lack of precise evidence of the effects of hypoxia, as the duration of hypoxia in each patient was unknown.

Bojarun A, Vieversyte Z, Jaruseviciene R, et al. Effect of obstructive sleep apnea on corneal morphological characteristics. Cornea. July 23, 2019. [Epub ahead of print].