可视化角膜生物测量仪生物力学指标对圆锥角膜诊断的灵敏度和特异度评估

Evaluation of the sensitivity and specificity of corneal visualization scheimpflug technology biomechanical index in the diagnosis of keratoconus

目的研究可视化角膜生物测量仪(CorvisST)的新评价指标—生物力学指数(CBI)诊断圆锥角膜的灵敏度和特异度,评价其在圆锥角膜诊断及角膜生物力学改变评估中的价值。方法采用诊断试验研究设计,纳入2018年4月至2018年8月期间在河南省人民医院屈光手术中心确诊的圆锥角膜患者49例66眼作为圆锥角膜组,同期纳入角膜屈光手术术前患者91例91眼作为对照组,完善相关眼科检查后,由同一检查者对所有受检者分别进行Pentacam和CorvisST检查。采用诊断试验的评价、一致性检验、受试者工作特征(ROC)曲线分析,得出参数CBI的灵敏度、特异度、一致性、Youden指数、ROC曲线下面积(AUC)。结果依据CBI诊断圆锥角膜者66眼。诊断试验的评价结果为CBI诊断圆锥角膜的灵敏度97.0%,特异度97.8%;一致性检验结果为Kappa=0.948,P<0.05。ROC曲线分析结果:CBI诊断圆锥角膜的灵敏度为98.5%,特异度为97.8%,Youden指数为96.3%,P<0.0001,AUC为0.996。结论角膜生物力学指标CBI诊断圆锥角膜的灵敏度和特异度高,与Rabinowitz圆锥角膜诊断标准结果的一致性好。CBI可作为诊断圆锥角膜的新生物力学指标。

Objective To study the sensitivity and specificity of parameter Corvis biomechanical index (CBI)- a new biomechanical index of Corvis ST in the diagnosis of keratoconus and evaluate the role of CBI in the diagnosis of keratoconus and the change of biomechanic. Methods A diagnostic trial study was adopted,and 66 eyes from 49 keratoconic patients (keratoconus group) and 91 right eyes from 91 myopic patients (control group) from April in 2018 to August in 2018 in Henan Eye Hospital were enrolled.Pentacam and Corvis ST examinations were performed by the same operator after the basic eye examinations.Using the evaluation of diagnostic test,consistency test,and receiver operating characteristic (ROC) curve analysis,gain the outcome of the sensitivity,specificity,consistency,Youden index,and area under the ROC curve of the parameter CBI.This study protocol was approved by Ethic Committee of Henan Eye Hospital and followed the Declaration of Helsinki.Written informed consent was obtained from each patient prior to any medical examination. Results Sixty eyes were diagnosed as keratoconus by the parameter CBI of Corvis ST.Evaluation of diagnosis test:the sensitivity was 97.0%,and the specificity was 97.8%;consistency check:Kappa=0.948, P <0.05.ROC curve analysis:the sensitivity was 98.5%,the specificity was 96.8%,Youden index was 96.3%, P <0.000 1 and AUC was 0.996. Conclusions CBI can separate healthy eyes from keratoconic eyes with highly sensitivity and specificity,which was highly consistency with results of Rabinowitz keratoconus diagnostic criteria.CBI could be used as a new biomechanical indicator for the diagnosis of keratoconus.