Normal tension glaucoma in patients with obstructive sleep apnea/hypopnea syndrome

To determine the prevalence of normal tension glaucoma (NTG) in patients with obstructive sleep apnea/hypopnea syndrome (OSAHS) and further investigate whether the severity of OSAHS would increase the risk of glaucoma.

Two hundred fifty-six participants were consecutively admitted for polysomnographic exam to diagnose OSAHS. All participants, then underwent a complete ophthalmologic evaluation, including best-corrected visual acuity, intraocular pressure, slit lamp biomicroscopy, gonioscopy, fundoscopy, automated visual field (VF), and retinal nerve fiber layer (RNFL) evaluation.

A total of 247 participants were enrolled in the study. Two hundred nine patients were OSAHS and 38 participants were classified as the normal group. Among the OSAHS patients, NTG was found in 12 patients with a prevalence of 5.7%, which was higher than that in the normal group (P=0.003). In the NTG patients, 1 was in the mild, 3 were in the moderate, and 8 were in the severe OSAHS group. There was no glaucoma patient in the normal group. The prevalence of NTG in moderate/severe OSAHS patients was 7.1%, significantly higher (P=0.033) than that in normal/mild OSAHS patients. The mean saturation of oxygen and lowest saturation of oxygen correlated with the average thickness of RNFL in the OSAHS patients.

Patients with OSAHS had a high prevalence of NTG, especially in patients with moderate and severe OSAHS. The severity of OSAHS inversely correlated with retinal nerve fiber layer thickness. Clinicians need to consider the possibility of glaucoma in patients with moderate and severe OSAHS.