title: [Changes of ophthalmic blood flow in obstructive sleep apnea-hypopnea syndrome].
abstract: OBJECTIVE
  To observe the ophthalmic artery (OA), central retinal artery (CRA) and posterior ciliary artery (PCA) blood flow and the changes of eye vascular auto-regulation in patients with obstructive sleep apnea-hypopnea syndrome (OSAS).
  
  
  METHODS
  It was a case-control study. Fifteen health overweight male adult (as normal control) and 42 patients with OSAS were randomly selected from examination center and sleep detection center, respectively. The OSAS patients were divided into mild (14 patients) and moderate and severe (28 patients) groups based on the apnea-hypopnea index (AHI). All subjects filled the sleep questionnaire and carried out polysomnogram monitoring all night for at least 7 hours. Fasting peripheral venous blood was collected at 7 AM on next day. The end-tidal CO(2) (ETCO(2)), intraocular pressure and color doppler sonography were examined next day to record the data in the inspection process before and after Mueller maneuver. Doppler ultrasound measurement of ocular blood flow diameter and blood flow velocity values were described in the median (max, min) and compared with Kruskal-Wallis test. And then two groups were compared with Bonferroni t test. Ocular blood flow velocity of patients with OSAS and PSG monitoring indicators were analyzed using partial correlation analysis.
  
  
  RESULTS
  OA inner diameter in moderate and severe OSAS group [0.08 (0.15, 0.06) cm] was lower than that in healthy control [0.15 (0.26, 0.11) cm] and the difference was statistically significant (P = 0.000). PCA inner diameter in moderate and severe OSAS group [0.10 (0.13, 0.07) cm] were higher than that in healthy controls [0.05 (0.09, 0.04) cm]. CRA peak systolic velocity (PSV) in moderate and severe OSAS group [16.50 (19.40, 13.10) cm/s] was greater than that in healthy controls [11.30 (16.70, 8.20) cm/s]. The differences between these two groups were statistically significant (PCA inner diameter: P = 0.000, CRA-PSV: P = 0.001). The difference of CRA end diastolic velocity (EDV) between the moderate and severe group [8.90 (9.90, 5.10) cm/s], mild group [7.00 (8.30, 4.50) cm/s] and healthy control group [5.50 (7.40, 3.40) cm/s] was statistically significant (χ(2) = 14.45, P < 0.05). PCA-PSV [32.50 (43.10, 19.10) cm/s] and PCA-EDV [12.80 (15.20, 5.70) cm/s] in the moderate and severe group were higher than those in healthy control group [22.60 (32.20, 12.40) cm/s] and [7.20 (11.20, 3.90) cm/s], as well as those in the mild group [24.00 (30.70, 13.30) cm/s] and [8.00 (9.90, 3.90) cm/s]. These differences were statistically significant (PCA-PSV: P = 0.000, 0.002; PCA-EDV: P = 0.000, 0.001). The diameter of OA and PCA correlated negatively with ETCO(2) (r = -0.41, -0.34; P < 0.05); CRA-PSV was correlated with SaO2 min (r = -0.37, P < 0.05). CRA-EDV was correlated with ETCO(2) and SaO2 mean (r = 0.57, -0.39; P < 0.05). PCA-PSV was correlated with SaO2 min and MAI (r = -0.34, 0.56; P < 0.05). PCA-EDV was correlated SaO2 min and MAI (r = -0.29, 0.61; P < 0.05).
  
  
  CONCLUSIONS
  The diameter and blood flow of OA, PCA and CRA change in OSAS patients. Compared with non-OSAS patients, the autoregulation function of PCA and CRA is weakened in OSAS patients.
authors.affiliation: Department of Respiratory, the Second Hospital of Shanxi Medical University, Taiyuan, China.
authors.forename: Lan-lan
authors.initials: LL
authors.lastname: Zhang
authors.forename: Lu
authors.initials: L
authors.lastname: Song
authors.forename: Yan-feng
authors.initials: YF
authors.lastname: Fan
authors.forename: Bei
authors.initials: B
authors.lastname: Wang
authors.forename: Zhuo-la
authors.initials: ZL
authors.lastname: Liu
mesh_terms: D000328:Adult; D001783:Blood Flow Velocity; D016022:Case-Control Studies; D019842:Ciliary Arteries; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D009880:Ophthalmic Artery; D012039:Regional Blood Flow; D012161:Retinal Artery; D020181:Sleep Apnea, Obstructive / Q000503:physiopathology*