| Objective:To observe the changes of corneal thickness in patients with obstructive sleep apnea syndrome（OSA）,and to explore the correlation between the monitoring parameters of nocturnal polysomnography and ocular parameters.Methods:Collect patients from respiratory department of the Second Affiliated Hospital of Fujian Medical University in March 2019 to July 2019,which with AHI≥5 and diagnosed as OSAHS by polysomnography monitoring were included in the experimental group.According to the severity of AHI,the experimental group was further subdivided into mild OSA group（5≤AHI≤15）、moderate OSA group（15<AHI≤30）、and severe OSA group（AHI>30）.Meanwhile,healthy people in the physical examination center of the Second Affiliated Hospital of Fujian Medical University during the same period were selected to be included in the control group（AHI<5）.Basic personal data and previous medical history of all subjects were included.Ocular parameters such as central corneal thickness（CCT）and axial length（AL）of all subjects were detected by optical coherence biometrics（ls-900）,polysomnography monitoring data of all subjects in the experimental group were recorded.The differences of ocular parameters between each group were compared,analyze the correlation between central corneal thickness、axial length and polysomnography monitoring parameters.Results:A total of 47 OSAHS patients（94 eyes）were enrolled in the experimental group,including 8 mildly OSA patients（16 eyes）,10 moderately OSA patients（20eyes）,and 29 severely OSA patients（58 eyes）,average age of 43.72±12.61years.The control group included 31 patients（62 eyes）with an average age of39.87±11.05 years.In comparison of polysomnography monitoring parameters among OSAHS patients in each experimental group,AHI（F=111.69,P<0.001）、LAT（F=13.47,P<0.001）、the min.SpO2（H=18.56,P<0.001）and the proportion of sleep stage I（F=4.24,P<0.05）had significant statistical significance,and there was a significant positive correlation between AHI,BMI and LAT（r=0.331,P<0.05;r=0.645,P<0.001）,BMI and LAT values increased with the rise of AHI,while there was a significant negative correlation between AHI and the min./ave.SpO2（r=-0.637,P<0.001;r=-0.442,P<0.01）,the min.SpO2 and the ave.SpO2 of OSAHS patients decreased with the increase of AHI value.In the comparative analysis of ocular parameters,the mean CCT of patients in the OSAHS experiment group was significantly lower than that of the control group（F=10.42 P<0.01）,however,there was no significant statistical difference in AL between the two groups（F=0.976,P>0.05）.The mean CCT values of mild OSA group、moderate OSA group、severe OSA group and the control group were 547.63±27.98,535.45±24.2,527.4±31.72,554.02±26.57μm respectively.The mean CCT values of the severe OSA group were the lowest,and the mean CCT values of the control group were the highest.In the evaluation of the correlation between polysomnography monitoring parameters and ocular parameters in the OSAHS experiment group,only a significant correlation was found between polysomnography monitoring parameters and CCT,CCT was negatively correlated with AHI and LAT（r=-0.328,P<0.05;r=-0.311,P<0.05）,CCT decreased with the increase of AHI and LAT.It also positively correlated with Avg.SpO2 and min.SpO2（r=0.302,P<0.05;r=0.310,P<0.05）,the lower the Avg./min.SpO2,the smaller the CCT value.However,there was no significant correlation between AL and AHI、Min./avg.SpO2 and LAT（P>0.05）.Conclusions:Compared with the healthy population,the central corneal thickness of OSAHS patients is thinner,and the decreasing trend of the thickness is related to the severity of OSAHS,while the axial length does not change significantly.Objective: By constructing the animal model of chronic intermittent hypoxia to understand the pathophysiological effects of chronic intermittent hypoxia on cornea in mice,and to investigate the possible mechanism and significance of central corneal thickness changes in OSAHS patients.Methods:A total of 35 male C57BL/6 mice aged 2-3 months and weighing 28-35 g were selected and randomly divided into 2 groups according to the asymmetric randomization method,25 in the chronic intermittent hypoxia group（experimental group）and 10 in the air simulation group（control group）.Construct the chronic intermittent hypoxia system and air simulation control system.Experiment group mice were placed in a closed box of chronic intermittent hypoxia to experience hypoxia/reoxygenation cycle every day,and control mice were placed in a closed box of air simulation control system for control experiment.The cycle began at 9:00 a.m.and ended at 17:00 p.m.each day,with a total cycle of 8 hours.The total process of model culture lasted for 1 month.After model culture,OCT was used to detect the parameters of central corneal thickness in mice,then collected the eyeball from all mice in the same time period.The pathophysiological changes of the cornea of mice were observed by pathological H-E staining,and the expression of Hif-1α mice in the cornea was detected by immunohistochemical staining.Results:In the chronic intermittent anoxic system,the average maximum oxygen concentration in the closed glass box was 21.2±0.34%,the average minimum oxygen concentration was 5.7±0.47%,and the average oxygen concentration showed a periodic rise and fall over time.There was a good fit between the two（R2=0.95,F=95.359,P<0.001）.In the detection of corneal parameters of mice by OCT,the mean CCT of mice in the experimental group was 105.53±6.7,and the mice in the control group was 117.87±6.01,there was a statistically significant difference in the mean CCT between the two groups（F=41.109,P < 0.001）. Pathology H-E staining results,the control group mice corneal epithelial cells on the hierarchical structure is clear,each cell layer connected closely,stroma layers are arranged in a regular manner,and fibrous connections are dense;in the experimental group,a number of corneal epithelial cells was significantly reduced,and the cell structure hierarchy was disordered,a large number of "vacuole" changes were observed.The fibers in the stroma layer were wrinkled and arranged in a disordered manner.In the immunohistochemical staining results,a small amount of weakly positive expression of Hif-1α was only observed in the corneal epithelium of the control group;the cornea of the experimental group showed strong positive expression in both corneal epithelium and endodermis,and a small amount of weak positive expression in the stroma layer.The positive expression level between the two groups showed significant statistical difference by comparing the average optical density（F=15.029,P<0.01）.Conclusions: Chronic intermittent hypoxia can cause increased expression of Hif-1α in the cornea of mice and decrease of central corneal thickness,which may be one of the important mechanisms for central corneal thickness changes in OSAHS patients. |
