Vascular Density Changes in Retina and Optic Nerve in OSAS Patients Using and Not Using CPAP

Background: To compare optic disc and macular vascular density (VD) between the control group and severe obstructive sleep apnea syndrome (OSAS) patients with using CPAP or not. Methods: Evaluation was made of 60 eyes of patients with severe OSAS using CPAP, 60 eyes of patients with severe OSAS not using CPAP, and 30 control groups, using OCTA RT XR Avanti (AngioVue software, Optovue Inc., Fremont, CA). Optic nerve head (ONH) and macular VD were measured in 4 quadrants. Retinal nerve fiber layer (RNFL) thickness and ganglion cell complex (mGCC) thickness were evaluated with Spectral Domain OCT for all patients. Results: In OSAS patients using CPAP, there was no significant thinning in the RNFL and mGCC thickness compared to the control group (p>0.05). Peripapillary VD was significantly different in superior-inferior-nasal quadrants in patients using CPAP (p<0.001, p=0.001, p=0.004, respectively) and was affected in the nasal quadrant in patients not using CPAP when compared with the control group (p=0.012). In eyes with no use of CPAP, macular superficial and perifoveal deep vascular density differed from control in all sectors (all, p0.05, respectively). Conclusion: Although OSAS causes a significant decrease in macular vessel density, it does not cause significant damage to structural elements such as RNFL and mGCC. While the use of CPAP has a positive effect by providing oxygenation to the macular superficial perfusion, it significantly reduces the peripapillary perfusion by causing an increase in IOP. Severe cases using CPAP may have a significant risk for glaucoma. Therefore, OCTA may be an ideal method to evaluate the changes in the retinal vascular system, which could be an effective parameter for the early evaluation of severe OSAS patients.