Measurement of central corneal thickness by high-resolution Scheimpflug imaging, Fourier-domain optical coherence tomography and ultrasound pachymetry

Authors

  • Shihao Chen,

    1. School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical College, Wenzhou, Zhejiang, China
    2. Key Laboratory of Vision Science, Ministry of Health P.R. China, Wenzhou, Zhejiang, China
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  • Jinhai Huang,

    1. School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical College, Wenzhou, Zhejiang, China
    2. Key Laboratory of Vision Science, Ministry of Health P.R. China, Wenzhou, Zhejiang, China
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  • Daizong Wen,

    1. School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical College, Wenzhou, Zhejiang, China
    2. Key Laboratory of Vision Science, Ministry of Health P.R. China, Wenzhou, Zhejiang, China
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  • Wuhe Chen,

    1. School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical College, Wenzhou, Zhejiang, China
    2. Key Laboratory of Vision Science, Ministry of Health P.R. China, Wenzhou, Zhejiang, China
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  • David Huang,

    1. Center for Ophthalmic Optics and Lasers, Doheny Eye Institute, Keck School of Medicine at the University of Southern California, Los Angeles, CA, USA
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  • Qinmei Wang

    1. School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical College, Wenzhou, Zhejiang, China
    2. Key Laboratory of Vision Science, Ministry of Health P.R. China, Wenzhou, Zhejiang, China
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Qinmei Wang, MD
Affiliated Eye Hospital of Wenzhou Medical College
270 West Xueyuan Road
Wenzhou
Zhejiang 325027
China
Tel: + 86 577 88068862
Fax: + 86 577 88832083
Email: cscrs@mail.eye.ac.cn or cscrs@sina.com

Abstract.

Purpose:  To compare the repeatability and reproducibility of central corneal thickness (CCT) measurements by high-resolution (HR) rotating Scheimpflug imaging and Fourier-domain optical coherence tomography (FD-OCT). CCT measurements were compared to those determined by ultrasound pachymetry (UP).

Methods:  In 35 healthy eyes, intra-observer repeatability for HR Scheimpflug (Pentacam) and FD-OCT (RTVue) systems was determined in consecutive images taken by an observer in the shortest time possible. Imaging was repeated again by a second observer to evaluate inter-observer reproducibility. The CCT measurements were compared among Scheimpflug, FD-OCT and UP images.

Results:  Mean coefficients of repeatability were 0.48% for Scheimpflug and 0.26% for FD-OCT. For Scheimpflug, the coefficient of inter-operator reproducibility was 0.87%. For FD-OCT, the coefficient of inter-operator reproducibility was 0.45%. The CCT measurements by Scheimpflug, OCT and UP images were (mean ± standard deviation) 521.7 ± 27.6 μm, 510.8 ± 28.6 μm and 516.5 ± 27.6 μm, respectively. The differences between instruments were statistically significant. The 95% limits of agreement in CCT were −0.7 to 22.5 μm for Pentacam-OCT, −13.4 to 24.0 μm for Pentacam-UP and −26.7 to 15.4 μm for OCT-UP. There was a high degree of correlation between CCT measured by all 3 methods.

Conclusion:  Noncontact measurements of CCT with HR Scheimpflug and FD-OCT systems yielded excellent repeatability and reproducibility and can be used interchangeably. Although both devices were comparable with UP; in clinical practice, the measurements acquired by optical modalities are not directly interchangeable with UP measurements.

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