Flockerzi Elias, Häfner Larissa, Xanthopoulou Kassandra, Daas Loay, Munteanu Cristian, Langenbucher Achim, Seitz Berthold
Department of Ophthalmology, Saarland University Medical Center, Homburg, Germany.
Department of Experimental Ophthalmology, Saarland University Medical Center, Homburg, Germany.
Acta Ophthalmol. 2022 Feb;100(1):e83-e90. doi: 10.1111/aos.14857. Epub 2021 Mar 22.
This study assesses the reliability of successive corneal biomechanical response measurements by the Corneal Visualization Scheimpflug Technology (CST, Corvis ST , Oculus Optikgeräte, Wetzlar, Germany) in different keratoconus (KC) stages.
A total of 173 eyes (15 controls: 15 eyes, and 112 KC patients: stages 1|1-2|2|2-3|3|3-4|4, n = 26|16|36|18|31|26|5 according to Topographical KC Classification, TKC) were repeatedly examined five times with the CST, each after repositioning the patient's head and re-adjusting the device. Tomographical analysis (Pentacam HR ; Oculus, Wetzlar, Germany) was performed once before and once after CST measurements. Outcome measures included (1) A1 velocity, (2) deformation amplitude (DA) ratio 2 mm, (3) integrated radius, (4) stiffness parameter A1 and (5) Ambrósio relational thickness to the horizontal profile (ARTh). The Corvis Biomechanical Index (CBI) is reported to be extracted out of these parameters. Mean values of the five measurements and Cronbach's α were calculated as a measure for reliability.
Ambrósio relational thickness to the horizontal profile and SPA1 were significantly higher in controls (534|123) compared to TKC1 (384|88), TKC2 (232|66), TKC3 (152|55) and TKC4 (71|27; p < 0.0001). The other parameters were similar in controls and TKC1 (A1 velocity: 0.148|0.151 m/s; integrated radius: 8.2|8.6 mm ), but significantly higher in TKC stages 2 to 4 (DA ratio 2 mm: 5.5|6.3|8.0; A1 velocity: 0.173|0.174|0.186 m/second; integrated radius: 10.9|12.8|19.0 mm ; p < 0.0001). All parameters proved to be highly reliable (Cronbach's α ≥ 0.834) and the corneal tomography remained unaffected.
The individual parameters included in the CBI (consisting of ARTh, SPA1, DA ratio 2 mm, A1 velocity and integrated radius) are highly reliable but differ KC stage-dependently.
本研究评估了采用角膜可视化Scheimpflug技术（CST，Corvis ST，德国韦茨拉尔Oculus Optikgeräte公司）对不同圆锥角膜（KC）阶段连续进行角膜生物力学反应测量的可靠性。
共对173只眼进行研究（15名对照者：15只眼，112例KC患者：根据地形学KC分类法分为1|1 - 2|2|2 - 3|3|3 - 4|4期，n分别为26|16|36|18|31|26|5），使用CST对每位患者的头部重新定位并重新调整设备后，重复检查5次。在CST测量前和测量后各进行一次断层扫描分析（Pentacam HR；德国韦茨拉尔Oculus公司）。观察指标包括：（1）A1速度；（2）2mm处的变形幅度（DA）比值；（3）综合半径；（4）硬度参数A1；（5）相对于水平轮廓的安布罗西奥相关厚度（ARTh）。据报道，可从这些参数中提取出Corvis生物力学指数（CBI）。计算5次测量的平均值和克朗巴赫α系数作为可靠性的指标。
与TKC1（384|88）、TKC2（232|66）、TKC3（152|55）和TKC4（71|27；p < 0.0001）相比，对照者的相对于水平轮廓的安布罗西奥相关厚度和SPA1显著更高（534|123）。对照者和TKC1的其他参数相似（A1速度：0.148|0.151m/s；综合半径：8.2|8.6mm），但在TKC 2至4期显著更高（2mm处的DA比值：5.5|6.3|8.0；A1速度：0.173|0.174|0.186m/秒；综合半径：10.9|12.8|19.0mm；p < 0.0001）。所有参数均被证明具有高度可靠性（克朗巴赫α系数≥0.834），且角膜断层扫描未受影响。
CBI中包含的各个参数（由ARTh、SPA1、2mm处的DA比值、A1速度和综合半径组成）具有高度可靠性，但因KC阶段不同而有所差异。
