From the School of Optometry and Ophthalmology and Eye Hospital (Mao, Zhuo, Feng, Wang, Chen, Huang), Wenzhou Medical University, the Key Laboratory of Vision Science (Mao, Zhuo, Wang, Chen, Huang), Ministry of Health P.R. China, and the Department of Ophthalmology (Zhang), First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China; the G.B. Bietti Foundation IRCCS (Savini), Rome, Italy.
J Cataract Refract Surg. 2013 Oct;39(10):1561-9. doi: 10.1016/j.jcrs.2013.04.029. Epub 2013 Jul 13.
To study the repeatability and reproducibility of corneal power measurements obtained with a new corneal topographer (Keratograph 4) and assess their agreement with those obtained by a rotating Scheimpflug camera (Pentacam HR) and an automated keratometer (IOLMaster).
Eye Hospital, Wenzhou Medical University, Wenzhou, China.
Observational cross-sectional study.
One eye of normal subjects was measured 3 times using all devices. Another operator performed an additional 3 consecutive scans using the corneal topographer. One week later, the first operator repeated the corneal power measurements using the corneal topographer. Parameters were flat meridian power, steep meridian power, average power, J0, and J45. The repeatability and reproducibility of measurements were assessed by the within-subject standard deviation (Sw), repeatability (2.77 Sw), coefficient of variation (CoV), and intraclass correlation coefficient (ICC). Agreement between devices was assessed using 95% limits of agreement (LoA).
Intraoperator repeatability and interoperator and intersession reproducibility of all measured parameters showed a CoV of less than 0.3%, a 2.77 Sw of 0.32 diopter or less, and an ICC of more than 0.97. No significant differences in the parameters were noted between the corneal topographer and Scheimpflug camera. Statistically significant differences existed between the parameters analyzed by the corneal topographer and the automated keratometer, except J45. The mean differences between the corneal topographer and the other 2 devices were small, and the 95% LoA were narrow for all measurements.
The new corneal topographer had excellent reliability and high agreement with the other 2 devices in corneal power measurements in normal subjects.
No author has a financial or proprietary interest in any material or method mentioned.
研究一种新型角膜地形图仪（Keratograph 4）测量角膜曲率的重复性和再现性，并评估其与旋转式Scheimpflug 相机（Pentacam HR）和自动角膜曲率计（IOLMaster）测量结果的一致性。
温州医科大学附属眼视光医院，中国温州。
观察性横断面研究。
使用所有设备对正常受试者的一只眼进行 3 次测量。另一位操作人员使用角膜地形图仪进行额外的 3 次连续扫描。一周后，第一位操作人员使用角膜地形图仪重复角膜曲率测量。参数包括平子午线屈光度、陡子午线屈光度、平均屈光度、J0 和 J45。通过个体内标准差（Sw）、重复性（2.77 Sw）、变异系数（CoV）和组内相关系数（ICC）评估测量的重复性和再现性。使用 95%一致性界限（LoA）评估设备之间的一致性。
所有测量参数的内操作者重复性、外操作者重复性和不同时间的再现性的 CoV 均小于 0.3%，2.77 Sw 小于或等于 0.32 屈光度，ICC 大于 0.97。角膜地形图仪和 Scheimpflug 相机测量的参数之间无显著差异。角膜地形图仪分析的参数与自动角膜曲率计存在统计学差异，除 J45 外。角膜地形图仪与其他 2 种设备之间的平均差异较小，所有测量的 95%LoA 较窄。
新型角膜地形图仪在正常受试者的角膜曲率测量中具有良好的可靠性和与其他 2 种设备的高度一致性。
