title: Precision of corneal thickness measurements obtained using the scheimpflug-placido imaging and agreement with ultrasound pachymetry.
abstract: 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.
authors: School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, 270 West Xueyuan Road, Wenzhou, Zhejiang 325027, China ; Key Laboratory of Vision Science, Ministry of Health, Wenzhou, Zhejiang, China.
authors: Jinhai
authors: J
authors: Huang
authors: G.B. Bietti Eye Foundation, IRCCS, Rome, Italy.
authors: Giacomo
authors: 0000-0003-0075-3582
authors: G
authors: Savini
authors: School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, 270 West Xueyuan Road, Wenzhou, Zhejiang 325027, China.
authors: Chengfang
authors: C
authors: Wang
authors: School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, 270 West Xueyuan Road, Wenzhou, Zhejiang 325027, China ; Key Laboratory of Vision Science, Ministry of Health, Wenzhou, Zhejiang, China.
authors: Weicong
authors: W
authors: Lu
authors: School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, 270 West Xueyuan Road, Wenzhou, Zhejiang 325027, China.
authors: Rongrong
authors: R
authors: Gao
authors: School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, 270 West Xueyuan Road, Wenzhou, Zhejiang 325027, China.
authors: Yuanguang
authors: Y
authors: Li
authors: School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, 270 West Xueyuan Road, Wenzhou, Zhejiang 325027, China ; Key Laboratory of Vision Science, Ministry of Health, Wenzhou, Zhejiang, China.
authors: Qinmei
authors: Q
authors: Wang
authors: School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, 270 West Xueyuan Road, Wenzhou, Zhejiang 325027, China ; Key Laboratory of Vision Science, Ministry of Health, Wenzhou, Zhejiang, China.
authors: Yune
authors: Y
authors: Zhao