超高频Scheimpflug角膜生物力学性能分析仪在圆锥角膜诊断中的应用

摘要

Objective To evaluate the cut-off points and diagnostic value in keratoconus of the ultra-high frequency Scheimpflug corneal biomechanical analyzer.Methods In this descriptive study,the same operator,using the same biomechanical analyzer,measured the 12 parameters of 93 keratoconus eyes and 84 control eyes.From Eye Hospital of Wenzhou Medical University during December 2013 to July 2015.The subjects were staged with the Amsler-Krumeich keratoconus classification.Differences of parameters between the two groups were analyzed,and the cut-off points (COP) for the parameters between the groups was analyzed by receiver operating characteristic (ROC) curves.The area under the curve (AUC) method was used to evaluate the diagnostic value of the 12 parameters.Results Except for applanation 1 length (AP1 L),applanation 2 time (AP2 T),and maximum deformation amplitude (A),all other parameters were significantly different between the keratoconus and the control eyes (P＜0.05 for each parameter).The cut-off points were AP1 T ≤6.90 ms,applanation 1 velocity (AP1 V) ＞0.17 m/s,applanation 2 length (AP2 L) ≤1.49 mm,applanation 2 velocity (AP2 V) ＞0.42 m/s,peak distance (PD) ≥4.78 mm,A ＞1.24 mm,maximum deformation curvature (C) ≤5.66 mm,maximum deformation time (T) ≤16.40 ms,intraocular pressure (IOP)≤ 13.50 mmHg,and central corneal thickness (CCT) ≤494 μm.Of all the parameters,C,AP1 V,and T had a medium level of diagnostic value.For these parameters,the AUC values were 0.738 (sensitivity 47.3％,specificity 94.0％),0.751 (sensitivity 61.3％,specificity 88.1％),and 0.887 (sensitivity 77.4％,specificity 91.7％),respectively.The CCT and PD had good diagnostic values,with AUCs of 0.926 (sensitivity 82.4％,specificity 92.9％) and 0.930 (sensitivity 92.5％,specificity 85.7％),respectively.Conclusion Some of the CorVis-ST parameters have medium to good diagnostic value for keratoconus,while the CCT and PD have good diagnostic value.This suggests that the CorVis-ST could provide useful assistance in the clinical diagnosis of keratoconus.%目的 评估新型超高频Scheimpflug角膜生物力学性能分析仪在圆锥角膜(KC)中的诊断阈值及诊断价值.方法 描述性研究.应用角膜生物力学性能分析仪测量2013年12月至2015年7月在温州医科大学附属眼视光医院就诊随机选取的KC患者53例(93眼,实验组)和屈光不正者84例(84眼,对照组)的12个相关参数,由同一位研究者操作;根据Amsler-Krumeich KC分期标准对KC进行分期,比较实验组与对照组参数差异,依据受试者工作特征曲线(ROC)探寻各参数在KC诊断阈值(COP),其后依据曲线下面积(AUC)评估各参数的诊断价值.结果 对于诊断阈值,与对照组相比,实验组的12个参数除第1次压平长度、第2次压平时间、最大形变幅度外,其余参数2组间差异均有统计学意义(P＜0.05).各参数诊断阈值分别为:第1次压平时间≤6.90 ms,第1次压平速度＞0.17 m/s,第2次压平长度≤1.49 mm,第2次压平速度＞0.42 m/s,最大形变峰间距≥4.78 mm,最大形变幅度＞ 1.24 mm,最大形变曲率≤5.66 mm,最大形变时间≤16.40 ms,眼压≤13.50 mmHg,中央角膜厚度≤494 μm;其中最大形变曲率、第1次压平速度与最大形变时间拥有中等诊断效果,其AUC分别为0.738(敏感度为47.3％,特异度为94.0％)、0.751(敏感度为61.3％,特异度为88.1％)、0.887(敏感度为77.4％,特异度为91.7％),中央角膜厚度与最大形变峰间距具有良好诊断效果,其AUC分别为0.926(敏感度为82.4％,特异度为92.9％)与0.930(敏感度为92.5％,特异度为85.7％).结论 依靠ROC AUC发现部分CorVis-ST参数对KC具有中度到良好诊断效果,其中角膜厚度及最大形变峰间距具有较好诊断效果,提示CorVis-ST可协助临床诊断KC.