圆锥角膜快速跨上皮交联手术前后Corvis ST参数的重复性及差异性

目的:评估圆锥角膜快速跨上皮交联手术前以及术后1mo Corvis ST参数的重复性及差异性。方法:研究纳入了30例30眼圆锥角膜患者进行分析。圆锥角膜患者术前和术后1mo分别进行三次Corvis ST重复测量。采用组内相关系数(ICC)、克伦巴赫alpha系数(Cronbach'α)、可重复性系数(RC)和变异系数(CV)评估Corvis ST参数的可重复性。采用配对t检验或Wilcoxon秩和检验评估术前与术后Corvis ST参数的差异。结果:术前39个Corvis ST参数中,26个(66.67%)参数重复性较好,6个(15.38%)参数重复性中等,7个(17.95%)参数的重复性较差。交联术后1mo,34个(87.18%)参数的重复性较好,3个(7.69%)参数重复性中等,2个(5.13%)参数的重复性较差。与术前相比,交联术后1mo圆锥角膜患者的眼压、生物力学校正眼压、第一次压平时间、曲率半径、第一次压平时的形变幅度、最大压陷偏离长度、角膜硬度参数值增加;而陡峭曲率、平坦曲率、平均曲率、第二次压平时间、2 mm最大形变幅度比值和综合半径值降低(均P<0.05)。结论:交联手术前和术后1mo Corvis ST参数均具有较好的可重复性,术后1mo圆锥角膜患者的角膜硬度较术前增加。

Repeatability and comparison of Corvis ST parameters before and after accelerated transepithelial corneal cross-linking in keratoconus eyes

AIM:To evaluate the repeatability and comparison of corneal visualization scheimpflug technology(Corvis ST)parameters in keratoconus eyes before and after accelerated transepithelial corneal cross-linking(ATE-CXL).METHODS:Thirty eyes of 30 progressive keratoconus patients were included in the prospective study.Three repeated corneal biomechanical measurements were performed preoperatively and one month postoperatively by Corvis ST.The interclass correlation coefficient(ICC)and 95%confidence interval(CI),Cronbach’α,repeatability coefficient(RC),and coefficient of variation(CV)were used to evaluate the repeatability of Corvis ST parameters.Paired t-test or Wilcoxon rank test was used to evaluate the differences between preoperative and postoperative data.RESULTS:At preoperative,26 of 39(66.67%)parameters showed good to excellent repeatability,6(15.38%)showed moderate,and 7(17.95%)showed poor repeatability.Similarly,34(87.18%)parameters showed good to excellent repeatability,3(7.69%)showed moderate,and 2(5.13%)showed poor repeatability after ATE-CXL.After ATE-CXL 1mo,the intraocular pressure(IOP),biomechanical corrected IOP(bIOP),first applanation time(A1T),Radius,deformation amplitude at the first applanation(A1DA),deflection length at the maximum deformation(HCDLL)and stiffness parameter at first applanation(SP A1)parameters increased,while the steep keratometry(Ks),flat keratometry(Kf),mean keratometry(Kmean),second applanation time(A2T),DA Ratio Max(2 mm)and integrated radius parameters decreased(all P<0.05).CONCLUSION:The repeatability of the Corvis ST parameters before and 1mo ATE-CXL follow up were both acceptable,and the corneal stiffness was improved after 1mo ATE-CXL.