Kanellopoulos Anastasios John
Department of Ophthalmology, The LaserVision Clinical and Research Eye Institute, Athens, Attiki, Greece.
Department of Ophthalmology, New York University Medical School, New York City, NY, USA.
Clin Ophthalmol. 2020 Sep 4;14:2583-2592. doi: 10.2147/OPTH.S251998. eCollection 2020.
To evaluate and compare the repeatability and agreement of Scheimpflug vs scanning-slit tomography of the cornea and the anterior chamber in terms of keratometric and tomographic indices in healthy eyes.
The 20 eyes of 10 healthy participants underwent 3 consecutive measurements using both Scheimpflug-tomography and scanning-slit tomography, diagnostic devices. Multiple corneal and anterior chamber tomographic parameters were recorded and evaluated to include corneal keratometry and its axis; corneal best-fit sphere (BFS), pachymetry mapping, angle kappa, anterior chamber depth (ACD), pupil diameter, and location. Repeatability for each device was assessed using the within each subject standard deviation of sequential exams, the coefficient variation (CV) and the intraclass correlation coefficient (ICC). Agreement between the two devices was assessed using Bland-Altman plots with 95% limits of agreement (LoA) and correlation coefficient (r).
Both devices were found to have high repeatability (ICC>0.9) both in keratometric and other tomographic measurements. Scheimpflug tomography's repeatability though appeared superior in the average keratometry values, anterior and posterior BFS, thinnest corneal pachymetry value and location (p<0.05). Agreement: Statistically significant inter-device differences were noted in the mean values of K1, K2, BFS, ACD and thinnest corneal pachymetry (p<0.05). Despite the agreement differences noted, the two devices were well correlated (r>0.8) in respective measurements with Scheimpflug delivering consistently lower values than the scanning-slit tomography device.
Scheimpflug-tomography repeatability was found to be superior to that of scanning-slit tomography in this specific study, in most parameters evaluated. Inter-device agreement evaluation suggests that reading from the two devices may not be used interchangeably in absolute values, yet they are well correlated with Scheimpflug delivering consistently lower values in most.
在健康眼中，就角膜测量和断层扫描指标评估并比较眼前节分析系统与扫描裂隙断层扫描术在角膜和前房方面的重复性和一致性。
10名健康受试者的20只眼睛使用眼前节分析系统和扫描裂隙断层扫描术这两种诊断设备连续进行3次测量。记录并评估多个角膜和前房断层扫描参数，包括角膜曲率及其轴位；角膜最佳拟合球镜（BFS）、角膜厚度测绘、kappa角、前房深度（ACD）、瞳孔直径及位置。使用每位受试者连续检查的标准差、变异系数（CV）和组内相关系数（ICC）评估每种设备的重复性。使用带有95%一致性界限（LoA）和相关系数（r）的布兰德-奥特曼图评估两种设备之间的一致性。
两种设备在角膜测量和其他断层扫描测量中均具有高重复性（ICC>0.9）。不过，眼前节分析系统的重复性在平均角膜曲率值、前后BFS、最薄角膜厚度值及位置方面似乎更优（p<0.05）。一致性：在K1、K2、BFS、ACD和最薄角膜厚度的平均值方面，设备间存在统计学显著差异（p<0.05）。尽管存在一致性差异，但两种设备在各自测量中相关性良好（r>0.8），眼前节分析系统给出的值始终低于扫描裂隙断层扫描设备。
在本特定研究中，在所评估的大多数参数方面，发现眼前节分析系统的重复性优于扫描裂隙断层扫描术。设备间一致性评估表明，两种设备的读数在绝对值上可能不可互换使用，但它们相关性良好，眼前节分析系统在大多数情况下给出的值始终较低。
