[Application of optical coherence tomography angiography in evaluation of retinal microvascular changes in patients with obstructive sleep apnea syndrome].

Objective: To assess the changes of retinal microvasculature in patients with obstructive sleep apnea syndrome (OSAS) evaluated by optical coherence tomography (OCTA). Methods: Adult OSAS patients who visited Beijing Tongren Hospital from Jan 2016 to Apr 2016 and complained of snoring were included in this study. The patients' general information, results of polysomnography, and OCTA parameters were collected. Patients were divided into three groups according to their apnea hypopnea index (AHI) results: Mild-moderate group, AHI≤30/h; Severe group, 30/h<AHI≤60/h; Extremely severe group, AHI>60/h, and clinical characteristics, polysomnography and OCTA parameters among the three groups were compared. Results: A total of 27 patients were included in this study with 21 males (77.8%) and 6 females (22.2%). Mean age was (41.7±10.0) years, and the mean body mass index was (27.9±4.5) kg/m(2;) Neck circumference was 31-48 cm, mean (39.8±4.3) cm; 8 patients (29.6%) suffered from hypertension that could be controlled; Epworth sleepiness scale scored 1-18 points and mean (8.5±4.4) scores; AHI ranged between 5.5 and 92.1/h with a mean of (46.4±28.6)/h. There were 9 (33.3%), 7 (25.9%), and 11 (40.7%) patients in mild-moderate group, severe group, and extremely severe group, respectively. Compared with severe group, the optic nerve head and radial peripapillary capillaries (RPC) peripapillary vascular density in extremely severe group were significantly decreased (62.4%±1.9% vs 60.3%±1.9%, P=0.041; 64.7%±1.7% vs 62.2%±2.3%, P=0.036). Conclusions: OCTA has rapid, safe, and objective characteristics in assessing the retinal microvascular changes in OSAS patients. Retinal microvascular damage in patients with OSAS is associated with the disease severity. Reduction of retinal microvascular density in patients with OSAS may be associated with intermittent hypoxia.