*School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China; †Key Laboratory of Vision Science, Ministry of Health PR China, Wenzhou, Zhejiang, China; ‡Hubei University of Medicine Affiliated Taihe Hospital, Shiyan, Hubei, China; §G. B. Bietti Eye Foundation-IRCCS, Rome, Italy; and ¶Department of Ophthalmology, Zhongshan Hospital, Fudan University, Shanghai, China.
Cornea. 2014 Jun;33(6):576-81. doi: 10.1097/ICO.0000000000000113.
The aim of this study was to evaluate the repeatability of central corneal thickness (CCT) measurements in normal eyes using 2 new noncontact specular microscopes (NCSMs) EM-3000 (Tomey, Japan) and SP-02 (CSO, Italy) and to compare the results with those obtained from an SP-3000P NCSM (Topcon, Japan) and ultrasound pachymetry (USP).
Seventy subjects were enrolled in a prospective study. A single experienced ophthalmologist performed tests with each of the 4 instruments. Measurements were obtained in the right eye during the same session. The testing sequence of the NCSM was randomly selected. After performing noncontact examinations, the USP was performed to derive the CCT measurements. Intraoperator repeatability was analyzed using within-subject coefficient of variation and intraclass correlation coefficients. The agreement between NCSMs or NCSM and USP was assessed with Bland-Altman plots and 95% limits of agreement (LoA).
The mean CCT values measured by SP-3000P, EM-3000, SP-02, and USP were 513.66 ± 33.14 μm, 529.12 ± 33.22 μm, 549.06 ± 40.27 μm, and 539.01 ± 35.73 μm, respectively. All coefficients of variation were <1.3%, and the intraclass correlation coefficients were >0.95. There were statistically significant differences between any 2 devices as determined by CCT measurements. The mean difference between paired comparisons was >9 μm. The 95% LoA ranges were broad, and the greatest 95% LoA was found to exist between SP-3000P and SP-02.
The new NCSMs and USP all show a high intraoperator repeatability for CCT measurements in normal eyes. However, interdevice agreement was poor and prevented the comparison of CCT measurements taken with different instruments.
本研究旨在评估两种新型非接触式共焦显微镜（NCSM）EM-3000（Tomey，日本）和 SP-02（CSO，意大利）在正常眼中测量中央角膜厚度（CCT）的重复性，并将结果与 SP-3000P NCSM（Topcon，日本）和超声角膜测厚术（USP）的结果进行比较。
70 名受试者参与了前瞻性研究。一名经验丰富的眼科医生使用 4 种仪器中的每一种进行测试。在同一次检查中，对右眼进行测量。NCSM 的测试顺序是随机选择的。完成非接触检查后，进行 USP 以获取 CCT 测量值。使用组内变异系数和组内相关系数分析操作者内重复性。使用 Bland-Altman 图和 95%一致性界限（LoA）评估 NCSM 或 NCSM 与 USP 之间的一致性。
SP-3000P、EM-3000、SP-02 和 USP 测量的平均 CCT 值分别为 513.66±33.14μm、529.12±33.22μm、549.06±40.27μm 和 539.01±35.73μm。所有变异系数均<1.3%，组内相关系数均>0.95。通过 CCT 测量值，任何两种设备之间均存在统计学差异。配对比较的平均差异>9μm。95%LoA 范围较宽，最大的 95%LoA 存在于 SP-3000P 和 SP-02 之间。
新型 NCSM 和 USP 均显示在正常眼中 CCT 测量具有较高的操作者内重复性。然而，设备间的一致性较差，阻止了对不同仪器测量的 CCT 值进行比较。
