Medical Faculty Mannheim, University of Heidelberg, Heidelberg, Germany.
University of Vienna, Vienna, Austria.
Eur J Ophthalmol. 2020 Nov;30(6):1287-1294. doi: 10.1177/1120672119864554. Epub 2019 Nov 20.
The aim of this study was to evaluate repeatability and reproducibility of newly calculated biomechanical parameters of the cornea, developed by our research group.
One eye from each of the 23 healthy subjects was measured three times consecutively, three times at different daytimes and on three different days. The within-subject standard deviation and coefficient of variation, as well as the intraclass correlation coefficient, were calculated for every parameter in each group.
Excellent repeatability and reproducibility (coefficient of variation < 5%, intraclass correlation coefficient > 0.75) was found for corrected values measured at A1, HC, and A2 time points (2nd A2 Time, 2nd A1 Time, 2nd HC Time, 2nd HC Def Amp and 2nd A1 Def Amp). Corneal-specific stiffness parameters, which showed good repeatability and reliability, were DA_cor (coefficient of variation = 4.02%, intraclass correlation coefficient = 0.919), KcLinear (coefficient of variation = 4.03%, intraclass correlation coefficient = 0.895), areaForceCornea (coefficient of variation = 3.34%, intraclass correlation coefficient = 0.853) and E2 (coefficient of variation = 4.1%, intraclass correlation coefficient = 0.78). Overall, most parameters fell into the category of good reliability (high intraclass correlation coefficient) and poor reproducibility (low coefficient of variation), including all the parameters describing extraocular deformation (DA_ext, AEPvED, AUC EDef, areaForceExtra, and ). Comparing the coefficient of variation values for intrasession, intersession and daytime measurements, there were no indices for diurnal changes.
Most parameters showed good repeatability and reliability. The extraocular stiffness parameters showed poor reproducibility. KcLinear can serve as a very reliable and repeatable indicator of corneal stiffness.
本研究旨在评估我们研究团队新开发的角膜生物力学参数的可重复性和再现性。
23 名健康受试者的每只眼睛连续测量三次，分别在不同的白天和不同的三天进行三次测量。在每个组中，为每个参数计算了组内标准差和变异系数以及组内相关系数。
在 A1、HC 和 A2 时间点测量的校正值（第二次 A2 时间、第二次 A1 时间、第二次 HC 时间、第二次 HC 挠度幅度和第二次 A1 挠度幅度）具有极好的可重复性和再现性（变异系数<5%，组内相关系数>0.75）。具有良好重复性和可靠性的角膜特异性硬度参数为 DA_cor（变异系数=4.02%，组内相关系数=0.919）、KcLinear（变异系数=4.03%，组内相关系数=0.895）、areaForceCornea（变异系数=3.34%，组内相关系数=0.853）和 E2（变异系数=4.1%，组内相关系数=0.78）。总体而言，大多数参数的可靠性较好（高组内相关系数），再现性较差（低变异系数），包括描述眼外变形的所有参数（DA_ext、AEPvED、AUC EDef、areaForceExtra 和 ）。比较日内、日间和日间测量的变异系数值，没有日间变化的指标。
大多数参数具有良好的可重复性和可靠性。眼外硬度参数的再现性较差。KcLinear 可以作为角膜硬度非常可靠和可重复的指标。
