OSA tied to preclinical thinning of peripapillary RFNL in young adults

There appears to be an association between obstructive sleep apnoea (OSA) and preclinical thinning of the peripapillary retinal nerve fibre layer (RNFL) in young adults, according to a study. This suggests that individuals with OSA since young adulthood may be at increased risk of glaucoma.

A total of 848 adults aged 19–22 years were included in this cross-sectional cohort study. Participants underwent an ophthalmic examination, including optical coherence tomography imaging of the optic disc and measurements of intraocular pressure, axial length and refractive error. Then they underwent an overnight polysomnography study to obtain measurements of apnoea-hypopnoea (AHI), peripheral oxygen saturation level and number of cortical arousals from sleep.

Using the AHI results, participants were grouped as follows: no OSA (AHI <5 events/hour), mild OSA (AHI ≥5 and <15 events per hour), moderate OSA (AHI ≥15 and <30 events per hour) or severe OSA (AHI ≥30 events per hour).

The median AHI was 2.2 events per hour (interquartile range, 1.0–4.4 events per hour) across the study cohorts. Of the participants, 178 (21.0 percent) had OSA, 150 had mild OSA, 26 had moderate OSA and two had severe OSA.

Unadjusted analyses revealed a thinner peripapillary RNFL at the inferotemporal (p=0.026) and superotemporal (p=0.008) segments in OSA participants than in those without OSA. Moreover, an association was found between thinner RNFL superotemporal segment and higher AHI results (p=0.007). Findings remained significant after adjusting for gender, body mass index, ethnicity and potential ocular confounders.

No significant differences were observed in optic disc measures between groups of OSA severity.

“Long-term follow-up of this cohort will allow further optic disc changes in relationship to polysomnography parameters to be documented and associations with future glaucoma diagnosis to be explored,” the authors said.