Glaucoma screening for moderate and severe OSA patients is recommended based on the significant amount of RNFL thinning seen on OCT. Photo: Mayo Clinic. Click image to enlarge.
Obstructive sleep apnea (OSA) adversely affects many aspects of circulation and is linked to several ocular disorders such as floppy eyelid syndrome, glaucoma, retinal vein occlusion, diabetic retinopathy, dry eye and keratoconus. When the optic nerve is affected, eyes experience retinal ganglion cell apoptosis and retinal nerve fiber layer (RNFL) thinning. To learn more about how differing severities of OSA affect the retina, researchers turned to OCT, recommending glaucoma screening for more severe OSA cases.
The hospital-based prospective study included 90 eyes of 90 newly diagnosed adult OSA patients. The researchers divided patients into mild (38.8%), moderate (30%) and severe (31.1%) categories of OSA based on the Apnea-Hypopnea Index (AHI).
They reported that the average RNFL thickness was significantly different among the three groups and inversely associated with AHI. Patients with severe OSA had thinner average RNFL thickness than patients with mild or moderate OSA. Looking at the four RNFL quadrants on the Cirrus HD-OCT, the researchers observed that only the superior quadrant RNFL thickness differed significantly among the three groups. This was also inversely associated with AHI, with severe OSA patients showing thinner RNFL than moderate OSA patients. Additionally, moderate and severe OSA patients had the highest IOP, and IOP differences among the three groups were significant.
The researchers concluded that moderate and severe OSA patients should be screened for glaucoma. “Early detection of RNFL thinning and raised IOP offers an opportunity for early detection of glaucoma in OSA patients,” they wrote in their paper. “For known glaucoma patients, screening for OSA may help in monitoring the progression of glaucoma and can prevent blindness in these patients.”
Devi TS, Agrawal A, Gupta N, et al. Retinal nerve fiber layer thickness in patients with obstructive sleep apnea. J Glaucoma. 2023. [Epub ahead of print].