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Journal of Ophthalmology
Volume 2017 (2017), Article ID 8515742, 4 pages
Research Article

Repeatability and Reproducibility of Intraocular Pressure and Dynamic Corneal Response Parameters Assessed by the Corvis ST

1Rio de Janeiro Corneal Tomography and Biomechanics Study Group, Rio de Janeiro, RJ, Brazil
2Department of Ophthalmology, Federal University of São Paulo, São Paulo, SP, Brazil
3Department of Ophthalmology & Visual Science and Department of Biomedical Engineering, The Ohio State University, Columbus, OH, USA
4School of Engineering, University of Liverpool, Liverpool, UK
5Department of Surgical Sciences, Division of Ophthalmology, University of Insubria, Varese, Italy
6Eye Center, Humanitas Clinical and Research Center, Via Manzoni 56, Rozzano, Italy
7Humanitas University, Via Manzoni 56, Rozzano, Italy
8Vincieye Clinic, Milan, Italy
9OCULUS Optikgeräte GmbH, Wetzlar, Germany
10Department of Biomedical Computer Systems, Faculty of Computer Science and Materials Science, Institute of Computer Science, University of Silesia, Bedzinska 39, 41-200 Sosnowiec, Poland

Correspondence should be addressed to Renato Ambrósio Jr

Received 7 February 2017; Accepted 20 April 2017; Published 6 June 2017

Academic Editor: Antonio Queiros

Copyright © 2017 Bernardo T. Lopes et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Purpose. To assess the repeatability and reproducibility of dynamic corneal response parameters measured by the Corvis ST (Oculus, Wetzlar, Germany). Methods. One eye randomly selected from 32 healthy volunteers was examined by the Corvis ST. Three different devices were used in an alternated random order for taking three measurements at each device in each subject. Standard intraocular pressure (IOP), the biomechanical-compensated IOP (bIOP), and DCR parameters were evaluated. The within-subject standard deviation (ζw) and coefficient of variation (CV) were assessed. Results. Regarding pressure indices, the ζw was below 1 mmHg for repeatability (0.98 for IOP and 0.89 for bIOP) and the CV was 6.6% for IOP and 6.1% for bIOP. For reproducibility, the ζw was around 1 mmHg (1.12 for IOP and 1.05 for bIOP) and the CV was 7.6% for IOP and 7.1% for bIOP. Most of DCR indices presented CV for repeatability below 4%. For reproducibility, the CV of most of the indices were below 6%. The deformation amplitude (DA) ratio in 1 mm and integrated radius were below 4% (1.2% and 3.8%, resp.). Conclusions. The Corvis ST showed good precision (repeatability and reproducibility) for IOP measurements and for DCR in healthy eyes.