Glaucoma Risk in Sleep Apnea Preceded By Retinal Nerve Fiber Layer Thinning

Glaucoma risk in patients with sleep apnea is increased significantly due to morphological changes to the retinal nerve layer layer, according to a study published in the Journal of Glaucoma. Patients with severe obstructive sleep apnea (OSA) have thinner average and superior quadrant retinal nerve fiber layer thicknesses (RNFLT) and higher intraocular pressures (IOP) compared with patients with mild or moderate OSA, raising patients’ glaucoma risk in those for whom sleep apnea is present, according to the report.

Researchers aimed to determine whether thinning of the RNFL correlates with severity of OSA. Because RNFL defects are an early sign of glaucoma, measuring the RNFL, along with IOP, may offer an opportunity for early disease detection. 

The researchers prospectively assessed 90 eyes of 90 patients diagnosed with OSA in North India between August 2020 and October 2021. All participants underwent comprehensive ophthalmic evaluation, including OCT imaging. Participants were stratified by mild (n=35; mean age, 45.71±11.37 years), moderate (n=27; mean age, 49.07±11.59 years), or severe obstructive sleep apnea (n=28; mean age, 54.79±11.38 years) according to apnea-hypopnea index (AHI) criteria. 

The average RNFLT was significantly different between the 3 groups (P =.002) with lower average RNFLT for participants with severe OSA (81.36±10.84 µm) compared with mild OSA (89.19±10.05 µm). Additionally, the data showed that, of the 4 quadrants observed, participants with severe obstructive sleep apnea had thinner superior quadrant RNFLT (97.18±17.64 µm) than those with moderate OSA (117.67±14.12 µm; P <.01). 

These effects were not skewed by the older average age of participants with severe OSA or the comorbidities of the groups.

Higher IOP was also associated with severe OSA (17.43±2.63 mm Hg) compared with mild OSA (16.11±2.07 mm Hg; P =.001). 

Together, these data suggest that glaucoma risk in those with sleep apnea is elevated. Patients with severe obstructive sleep apnea may benefit from early glaucoma risk evaluation.

“Attention should be paid to the patients with OSA as it may have an impact on RNFLT,” according to the researchers. “OSA patients should be screened for glaucoma as early detection of glaucoma can reduce vision loss in these patients.”

Limitations of the study include small sample size and lack of a control group.