【摘要】 目的 基于切向曲率分析不同锥体位置圆锥角膜(KC)的生物力学特征。方法 本研究为回顾性研究，纳入100只KC眼[根据前表面切向曲率最大值所在位置将KC分为中央组(51眼)(角膜中心3 mm内)和旁中央组(49眼)(角膜中心3 mm外)]和51只正常眼(正常组)。使用Pentacam和Corvis ST获取眼部形态学和生物力学参数。分别调整眼压(IOP)与中央角膜厚度(CCT)、生物力学矫正眼压(bIOP)与角膜最薄点厚度(TCT)后进行组间参数比较。使用受试者工作特征(ROC)曲线分析参数诊断效能。结果 IOP、bIOP、CCT及TCT参数在旁中央组与正常组、中央组与正常组间比较，差异均有统计学意义(均为P<0.05)。调整前，CBI、Integrated Radius、Max Inverse Radius、DA Ratio Max(1 mm)、Peak Dist、dArc Length Max、cCBI、Radius、A1 Deflection Area、A1 Deflection Amp.、HC dArc Length参数在旁中央组与中央组间比较，差异均有统计学意义(均为P<0.05);调整CCT与IOP、TCT与bIOP后，仍有11个角膜生物力学参数组间比较差异均有统计学意义(均为P<0.05)。ROC曲线分析结果显示，TBI、cCBI、CBI、Integrated Radius、Max Inverse Radius在鉴别中央型KC与正常角膜时能力较高(AUC=1.000、1.000、1.000、0.998、0.997),在鉴别旁中央型KC与正常角膜时的诊断效能有所降低(AUC=1.000、0.968、0.968、0.936、0.948)。结论 锥体位置是影响KC生物力学表现的关键变量。中央型与旁中央型KC之间存在显著的生物力学差异，且此差异独立于角膜厚度与IOP。临床医生在诊断早期KC的过程中，应结合锥体位置对生物力学参数进行综合判断，提高临床筛查与诊断的准确性。更多还原

【Abstract】 Objective To analyze the biomechanical characteristics of keratoconus(KC) with different cone positions based on tangential curvature. Methods This retrospective study included 100 KC eyes [divided into a central group(51 eyes,within 3 mm of the corneal center) and a paracentral group(49 eyes,outside 3 mm of the corneal center) based on the location of the maximum tangential curvature on the anterior surface] and 51 normal eyes(control group). Morphological and biomechanical parameters of the eyes were obtained using Pentacam and Corvis ST. After adjusting for intraocular pressure(IOP) and central corneal thickness(CCT),as well as biomechanically corrected intraocular pressure(bIOP) and thinnest corneal thickness(TCT),intergroup parameter comparisons were conducted. The diagnostic efficacy of the parameters was analyzed using receiver operating characteristic(ROC) curves. Results The IOP,bIOP,CCT,and TCT parameters were compared between the paracentral group and the normal group,as well as between the central group and the normal group,and the differences were statistically significant(all P < 0. 05). Before adjustment,CBI,Integrated Radius,Max Inverse Radius,DA Ratio Max(1 mm),Peak Dist,dArc Length Max,c CBI,Radius,A1 Deflection Area,A1 Deflection Amp.,and HC dArc Length parameters were compared between the paracentral group and the central group,and the differences were statistically significant(all P < 0. 05). After adjusting CCT and IOP,TCT and bIOP,there were still 11 mechanical parameters with statistically significant differences between groups(all P < 0. 05). The ROC curve analysis results showed that TBI,cCBI,CBI,Integrated Radius,and Max Inverse Radius had a higher ability to distinguish central KC from normal cornea(AUC = 1. 000,1. 000,1. 000,0. 998,0. 997),while their diagnostic efficiency decreased when distinguishing paracentral KC from normal cornea(AUC = 1. 000,0. 968,0. 968,0. 936,0. 948).Conclusion The position of the cone is a key variable affecting the biomechanical performance of KC. There is a significant biomechanical difference between central and paracentral KC,and this difference is independent of corneal thickness and IOP. When diagnosing early KC,clinicians should comprehensively judge biomechanical parameters based on the cone position to improve the accuracy of clinical screening and diagnosis.更多还原