Correlation Between Anisometropia And Sleeping Position Preference In OSAHS Patients And The Role Of MMP-2、 MMP-9in The Cornea And Sclera Of Mice With Chronic Intermittent Hypoxia

Objective: To discuss the relationship between anisometropia and sleeping positionpreference in OSAHS patients.Methods：Sixty-one patients diagnosed with OSAHS in Department of RespiratoryMedicine of the Second Affiliated Hospital of Fujian Medical University betweenSeptember,2012and March,2013were included in the experimental groupSixty-seven healthy people were chosed as the control group. All the cases were askedfor personal information and medical history, and ophthalmological check-upinvolved computer optometry, corneal topography, and optical coherenceinterferometry (IOL Master). According to sleeping position preference, experimentalgroup(OSAHS group) was divided into two groups: one group always preferredsleeping on one certain side (O-S group), and the other had no such apreference(O-NS group). Likewise, the control group was divided into two groups:N-S group and N-NS group. The incidences of anisometropia, the values of cornealtopography, and the ocular axial lengths in all groups were compared, besides, theincidences of anisometropia in different degrees of OSAHS patients were analysed.Results： Twenty-nine out of the61OSAHS patients were found to haveanisometropia(47.54%);11out of the67healthy people were found to haveanisometropia in normal group(16.42%). The incidence of anisometropia in theexperimental group was significantly higher than that in control group（χ2=14.40，P＜0.05）. Twenty-two out of32patients in O-S group had anisometropia(68.75%), andthe ipsilateral ocular myopic degree or astigmatic degree of the preferred sleepingside(the involved eye) was higher than that of the contralateral eye in those20patient（s62.50%）. Seven out of29patients in O-NS group(24.14%),4out of24casesin N-S group(16.67%), and7out of43cases in N-NS group（16.28%）were diagnosedwith anisometropia. The incidence of anisometropia in O-S group was significantly higher than that in the other three groups(χ2=12.14, χ2=14.96, χ2=21.30, all, P＜0.05).The incidence of anisometropia in mild, moderate and severe OSAHS were20.00%,26.32%,62.50%, the incidence of anisometropia between each group was difference(χ2=14.25, P<0.05), The incidence of anisometropia in severe OSAHS patients washigher than that in the other three groups (χ2=3.95, P <0.05; χ2=6.25, P <0.05). Thecorneal topography showed that the values of SAI, SRI and CYL of the OSAHSgroup(122eyes) were higher than that of the control group(134eyes)(t=82.65, t=16.65,t=5.88, all, P<0.05);. In O-S group, the values of SAI, SRI and CYL of the involvedeyes were higher than that of the contralateral eyes(t=10.66, t=2.65, t=3.47, all,P<0.05); IOL Master showed that in the22patients with anisometropia in O-S group,ocular axial length of the involved eye was longer than that of the contralateral eye (P＜0.05).Conclusions: OSAHS patients who have sleeping position preference are prone todevelop anisometropia, and the incidence of anisometropia is positively interrelated tothe severity of OSAHS. In OSAHS patients, the myopic degree or astigmatic degreeof the involved eye is higher than that of the contralateral eye, the ocular axial lengthof the involved eye is longer, and the values of SAI, SRI and CYL of the involved eyeare higher. Objective: To explore the implications of the expression of MMP-2and MMP-9inthe cornea and sclera of mice with chronic intermittent hypoxia byimmunohistochemistry.Methods：36male mice provided by Quanzhou Medical College ExperimentalAnimal Center (Permit No. SYXK (Min)2009-0004) were enrolled in this study. Allthe mice were2months old, and body weight ranged from25g to28g.16mice isused to validate the model of chronic intermittent hypoxia,20mice groupingexperiments. Verify that the chronic intermittent hypoxia model is successful, The20mice were randomly divided into two groups: experimental group and control group.Each group had10mice, and the mean body in the experimental and control groupwas26.31±0.75g,26.70±0.70g, respectively. The mice in the experimental groupwere placed in an environment of chronic intermittent hypoxia.To put it concisely, ateight thirty every morning, the mice in the experimental group were placed in a sealedbox to experience hypoxia/re-oxygenation circulations, and the cycle repeated tillfour thirty every afternoon. The mice in the control group were placed in a sealed boxconnected to circulating air. The experiment lasted12weeks. Twelve weeks later, allthe20mice were decapitated, and samples were taken from each mousesimultaneously, then the expression of MMP-2and MMP-9in the cornea and scleraof those mice was detected by immunohistochemical staining.Results： Cyclical changes in oxygen concentration can cause SaO2cyclicalfluctuations in mice, Changes in line with OSHAS patients SaO2, indicating that amouse model of chronic intermittent hypoxia was successfully established.Immunohistochemistry showed there was an increased MMP-2and MMP-9expression in the cornea and sclera of mice with chronic intermittent hypoxiacompared to that of the control group(all, P＜0.05). Conclusions: OSAHS patients who have sleeping position preference are prone todevelop anisometropia. This might be associated with the increased MMP-2andMMP-9expression, for the latter can reduce the tension of the eyeball structure.