目的:本研究旨在评估更新的应力应变指数(SSIv2)和其他CorvisST生物力学参数在区分不同疾病阶段的圆锥角膜中的能力,正常的眼睛
方法:诊断准确性分析以区分疾病分期。
方法:1084只眼,分为正常组(199只眼),圆锥角膜(FFKC,194只眼睛),亚临床圆锥角膜(SKC,113眼),轻度临床圆锥角膜(CKC-I,175只眼睛),中度临床圆锥角膜(CKC-II,204眼)和严重的临床圆锥角膜(CKC-III,199只眼睛)。对每只眼睛进行CorvisST检查以确定中央角膜厚度(CCT)。生物力学校正眼内压(bIOP),SSIv2等八个Corvis参数包括SSIv1、SP-A1、A1T、ARTh,IIR,DAM,DARatio2和CBI。通过受试者工作特征曲线分析了这些参数在诊断圆锥角膜中的敏感性和特异性。
结果:CCT和bIOP校正前后,SSIv2和ARTh显著高于,正常组的IIR和CBI显著低于正常组,SKC组和3个CKC组(均P<0.05)。SSIv2、ARTh、IIR,CBI与CKC严重程度有关(均P<0.05)。在区分正常眼和FFKC时,SSIv2的AUC明显高于所有其他Corvis参数,紧随其后的是IIR,ARTh和CBI。
结论:CorvisST的更新的SSI在区分正常角膜和角膜角膜方面表现出优异的性能,和不同圆锥角膜阶段的角膜之间。类似,但不太明显,性能由IIR证明,ARTh和CBI。
This study seeks to evaluate the ability of the updated stress strain index (SSIv2) and other Corvis ST biomechanical parameters in distinguishing between keratoconus at different disease stages and normal eyes.
Diagnostic accuracy analysis to distinguish disease stages.
1084 eyes were included and divided into groups of normal (199 eyes), forme fruste keratoconus (FFKC, 194 eyes), subclinical keratoconus (SKC, 113 eyes), mild clinical keratoconus (CKC-Ⅰ, 175 eyes), moderate clinical keratoconus (CKC-Ⅱ, 204 eyes), and severe clinical keratoconus (CKC-Ⅲ, 199 eyes). Each eye was subjected to a Corvis ST examination to determine the central corneal thickness (CCT), biomechanically corrected intraocular pressure (bIOP), SSIv2 (updated stress-strain index), and other 8 Corvis parameters including the stress-strain index (SSIv1), stiffness parameter at first applanation (SP-A1), first applanation time (A1T), Ambrósio relational thickness to the horizontal profile (ARTh), integrated inverse radius (IIR), maximum deformation amplitude (DAM), ratio between deformation amplitude at the apex and at 2 mm nasal and temporal (DARatio2), and Corvis biomechanical index (CBI). The sensitivity and specificity of these parameters in diagnosing keratoconus were analyzed through receiver operating characteristic curves.
Before and after correction for CCT and bIOP, SSIv2 and ARTh were significantly higher and IIR and CBI were significantly lower in the normal group than in the FFKC group, SKC group and the 3 CKC groups (all P < .05). There were also significant correlations between the values of SSIv2, ARTh, IIR, CBI, and the CKC severity (all P < .05). AUC of SSIv2 was significantly higher than all other Corvis parameters in distinguishing normal eyes from FFKC, followed by IIR, ARTh and CBI.
Corvis ST\'s updated stress-strain index, SSIv2, demonstrated superior performance in differentiating between normal and keratoconic corneas, and between corneas with different keratoconus stages. Similar, but less pronounced, performance was demonstrated by the IIR, ARTh and CBI.