Vascular density changes in retina and optic nerve in obstructive sleep apnea syndrome cases

Purpose To evaluate changes in macular and optic nerve blood supply in cases of severe-obstructive-sleep-apnea-syndrome (OSAS) using or not using continuous-positive-airway-pressure (CPAP). Methods Sixty cases of severe-OSAS and 30 healthy-cases were included in this cross-sectional study. Thirty of the OSAS cases were not using CPAP. Both eyes were included in all cases. Optic nerve and macular-vascular-density (VD) were evaluated in the four quadrants using an RT XR Avanti (AngioVue-software-Optovue-Inc.-Fremont-CA-USA) optic-coherence-tomography-angiography (OCTA) device. Retinal-nerve-fiber-layer (RNFL) and ganglion-cell-complex (mGCC) thicknesses were also evaluated in all cases using spectral-domain-optic-coherence-tomography. Results No statistically significant difference was observed in RNFL or mGCC thicknesses in the OSAS-cases compared to the healthy-cases (p > 0.05 for both). Peripapillary-VD decreased significantly in the superior-inferior-nasal quadrants in the cases using CPAP compared to the healthy-cases (p < 0.001, p = 0.003, and p = 0.010, respectively). Only nasal-peripapillary-VD was lower in the cases not using CPAP than in the healthy-cases (p = 0.016). Macular-superficial VD were significantly lower in the cases not using CPAP compared to the healthy-cases (p < 0.05), whereas there was no difference in the cases using CPAP (p > 0.05). Duration of using CPAP was moderately correlated with peripapillary-VD in the superior and inferior quadrants (r = 0.463 p = 0.008, r = 0.553 p = 0.001, respectively). Conclusion Obstructive-sleep-apnea-syndrome causes a decrease in vascular density at the optic nerve head and predominantly in the macula and is a risk for glaucoma. It has been observed that macular perfusion improves early in patients using CPAP, whereas peripapillary perfusion responds later. Therefore, OCTA may represent an ideal method for evaluating the retinal vascular system in cases of OSAS.