Precision of Corneal Thickness Measurements Obtained Using the Scheimpflug-Placido Imaging and Agreement with Ultrasound Pachymetry

• Published in: Journal of Ophthalmology Vol. 2015; no. 2015; pp. 1 - 6
• Main Authors: Zhao, Yune, Li, Yuanguang, Gao, Rongrong, Lu, Weicong, Wang, Chengfang, Savini, G., Huang, Jinhai, Wang, Qinmei
• Format: Journal Article
• Language: English
• Published: Cairo, Egypt Hindawi Limiteds 01.01.2015; Hindawi Publishing Corporation; Hindawi Limited; Wiley
• Subjects: Care and treatment; Confidence intervals; Contact lenses; Cornea; Corneal diseases; Diagnosis; Diagnostic imaging; Methods; Studies; Surgery; Topography; Ultrasonic imaging; China; Italy; Japan
• ISSN: 2090-004X; 2090-0058
• DOI: 10.1155/2015/328798

Purpose. To assess the reliability and comparability of measuring central corneal thickness (CCT) and thinnest corneal thickness (TCT) using a new Scheimpflug-Placido analyzer (TMS-5, Japan) and ultrasound (US) pachymetry. Methods. Seventy-six healthy subjects were prospectively measured 3 times by 1 operator using the TMS-5, 3 additional consecutive scans were performed by a second operator, and ultrasound (US) pachymetry measurements were taken. The test-retest repeatability (TRT), coefficient of variation (CoV), and intraclass correlation coefficient (ICC) were calculated to evaluate intraoperator repeatability and interoperator reproducibility. Agreement among the devices was assessed using Bland-Altman plots and 95% limits of agreement (LoA). Results. The intraoperators TRT and CoV were <19 μm and 2.0%, respectively. The interoperators TRT and CoV were <12 μm and 1.0%, respectively, and ICC was >0.90. The mean CCT and TCT measurements using the TMS-5 were 15.97 μm (95% LoA from −26.42 to −5.52 μm) and 20.32 μm (95% LoA from −30.67 to −9.97 μm) smaller, respectively, than those using US pachymetry. Conclusions. The TMS-5 shows good repeatability and reproducibility for measuring CCT and TCT in normal subjects but only moderate agreement with US pachymetry results. Caution is warranted before using these techniques interchangeably.