Corvis ST测量近视患者新型角膜生物力学参数的重复性及其影响因素

Repeatability of new Corvis ST parameters and influencing factors in myopia patients

目的观察角膜生物力学分析仪(corneal visualization scheimpflug technology,Corvis ST)测量近视患者角膜生物力学参数的重复性,探讨影响新增Corvis ST参数重复性的因素。方法采用诊断试验研究设计。连续纳入2017年9—10月在河南省立眼科医院屈光手术中心拟接受屈光手术的近视患者95例190眼,其中男34例,女61例。所有受试者均进行Corvis ST 5次重复性测量。通过比较组内相关系数(ICC)、克隆巴赫系数(Cronbachα)和重复性系数(repeatability coefficient,RC)评估各参数的可重复性;通过多重线性回归分析影响Corvis ST新增参数重复性的因素。结果本研究共纳入了39个Corvis ST测量参数。其中26个参数Cronbachα系数及ICC系数均大于0.75,重复性较好,占总参数的66.7%;4个参数Cronbachα系数及ICC系数在0.60~0.75之间,重复性一般,占10.3%,最大偏离振幅时间(DLAMT)的Cronbachα系数及ICC系数低于0.60,重复性较差,占2.5%;1 mm最大形变幅度比值(DA ratio max[1 mm])、2 mm最大形变幅度比值(DA ratio max[2 mm])、最大反向凹面半径、水平方向Ambrôsio相关厚度(ARTh)、生物力学校正眼压(bIOP)、综合半径、角膜硬度参数(SPA1)和生物力学指数(CBI)8个新增参数的Cronbachα系数及ICC系数均在0.920以上,重复性均较好。多重线性回归结果显示眼压越大,bIOP的重复性测量标准差越大(β=0.210,P=0.010);中央角膜厚度(CCT)越大,DA Ratio Max[1 mm]的重复性测量标准差越小(β=-0.218,P=0.008);CCT越大,DA Ratio Max[2 mm]的重复性测量标准差越小(β=-0.295,P<0.001);柱镜度数、眼轴和CCT越大,CBI的重复性测量标准差越小(β=-0.190、-0.148、-0.428,均P<0.05)。结论Corvis ST测量近视患者角膜生物力学参数的重复性较好;柱镜度数、眼轴和CCT可影响CBI参数测量的重复性。

Objective To evaluate the repeatability of corneal biomechanics parameters measured by Corneal Visualization Scheimpflug Technology(Corvis ST)and explore the factors that influence the repeatability.Methods A diagnostic test study was performed.A total of 190 eyes in 95 myopia patients(34 males and 61 females)were enrolled from September to October 2017 in Henan Eye Hospital.All the subjects underwent 5 repeated examinations with the Corvis ST.The intraclass correlation coefficient(ICC),Cronbachαcoefficients and repeatability coefficient(RC)were computed to evaluate repeatability of Corvis ST parameters.The multiple linear regression analysis was used to study the factors that affect the magnitude of the test-retest variability(within subject SD)of new Corvis ST parameters.This study was approved by the Ethics Committee of Henan Eye Hospital(HNEECKY-2019[5]),and written informed consent was obtained from each subject.Results Among the 39 biomechanics parameters,The ICC and Cronbachαwere greater than 0.75 for 26 parameters,within 0.60-0.75 for 4 parameters,and lower than 0.60 for deflection amplitude max time(DLAMT).The ICC and Cronbachαof DA ratio max[1 mm],DA ratio max[2 mm],max inverse radius,Ambrósio's relational thickness horizontal(ARTh),biomechanical intraocular pressure(bIOP),integrated radius,stiffness parameter applanation 1(SPA1)and Corvis biomechanical index(CBI)were all above 0.920.The multivariate regression results indicated that the within subject SD of bIOP increased with the increase of IOP(β=0.210,P=0.010).The within subjects SD of DA Ratio Max[1 mm]decreased with the increase of central corneal thickness(CCT)(β=-0.218,P=0.008).The within subjects SD of DA Ratio Max[2 mm]decreased with the increase of CCT(β=-0.295,P<0.001).The within subject SD of CBI decreased with the increase of astigmatism,axial lengths and CCT(β=-0.190、-0.148、-0.428,all P<0.05).Conclusion The Corvis ST parameters showed favorable measurement repeatability in myopia patients,especially for the new parameters.Astigmatism,axial lengths and CCT significantly affected the repeatability of CBI.