Optic disc measures in obstructive sleep apnea: a community-based study of middle-aged and older adults

Precis: This study found an association between thinner superotemporal retinal nerve fiber layer (RNFL) and obstructive sleep apnea (OSA). However, the lack of association of sleep apnea with other disc measures does not support a link with glaucoma.

Aim: Previous findings on the link between OSA and increased glaucoma risk have been inconsistent. In a community-based study of middle-aged and older adults, we explored for differences in optic disc measures that may resemble preclinical glaucomatous changes in relation to OSA status and severity.

Methods: A total of 865 participants (46 to 67 y; 45% male) underwent an at-home sleep study during which their apnea-hypopnea index (AHI) and sleep oxygen saturation level were measured. Participants were determined to have no OSA (AHI<5 events/h), mild (AHI 5 to 15), moderate (AHI 16 to 30), or severe OSA (AHI>30). At a 6-year follow-up visit, the optic discs of both eyes were imaged using spectral domain optic coherence tomography to measure the Bruch membrane opening-minimum rim widths and RNFL thicknesses.

Results: On the basis of the AHI, 411 participants (48%) had OSA, of whom 92 (11% of total sample) and 26 (3%) had moderate and severe OSA, respectively. In the multivariate analysis, participants with severe OSA had thinner RNFL superotemporally than those without OSA or with mild OSA (P<0.001 and 0.001, respectively). In addition, superotemporal RNFL was inversely associated with AHI (P=0.004) and sleep time with oxygen saturation level <90% (P=0.005). There was no association between OSA measures and Bruch membrane opening-minimum rim widths.

Conclusions: Our findings do not provide strong evidence of a link between measures of OSA and the optic disc. However, the association between increased OSA severity and thinner superotemporal RNFL has been reported consistently in previous studies and thus warrants further evaluation.