Reproducibility, and repeatability of corneal topography measured by Revo NX, Galilei G6 and Casia 2 in normal eyes

• Published in: PloS one 2020-04, Vol.15 (4), p.e0230589
• Main Authors: Wylęgała, Adam, Mazur, Robert, Bolek, Bartłomiej, Wylęgała, Edward
• Format: Article
• Language: English
• Subjects: Adult; Biology and Life Sciences; Cameras; Cataracts; Cornea; Cornea - anatomy & histology; Cornea - physiology; Corneal Pachymetry - methods; Corneal Topography - methods; Correlation coefficient; Correlation coefficients; Dentistry; Engineering and Technology; Eye (anatomy); Female; Hospitals; Humans; Innovations; Male; Measurement; Measurement techniques; Medical research; Medicine; Medicine and Health Sciences; Optical Coherence Tomography; Physical Sciences; Power (Philosophy); Prospective Studies; Publishing industry; Reproducibility; Reproducibility of Results; Research and Analysis Methods; Statistical analysis; Tomography; Tomography, Optical Coherence - methods; Topography
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0230589

To test the repeatability and reproducibility of the topography module in posterior segment spectral domain optical coherence tomography with Revo NX (new device) and to compare keratometry values obtained by a Scheimpflug tomography (Galilei G6) and a swept source OCT (Casia 2). In this prospective study, healthy subjects with nonoperated eyes had their central corneal thickness (CCT), anterior and posterior K1/K2 corneal power measured with the new device. Two operators made 6 measurements on the new device to check intraobserver repeatability and reproducibility, and measurement on Casia 2 and Galilei G6. Bland-Altman plots were used to assess the agreement between the devices for each analyzed variable. 94 eyes (94 patients) were studied. All devices produced significantly different mean CCT, the highest for Galilei 569.13±37.58 μm followed by Casia 545.00 ±36.15 μm and Revo 537.39±35.92 μm. The mean anterior K1 was 43.21 ± 1.37 for Casia 2 43.21 ± 1.55 for Revo NX and 43.19 ± 1.39 for Galilei G6, and the differences were insignificant p = 0.617. The posterior K1 for Revo NX was -5.77 ± 0.25 whereas for Casia 2 it was -5.98±0.22 and for Galilei G6-6.09±0.28 D p< 0.0001. The Revo NX showed intraclass correlation coefficient ranging from 0.975 for the posterior K2 surface, and 0.994 for anterior K1 and 0.998 for CCT. Revo NX is independent of the user and offers a high level of repeatability for the anterior and posterior cornea. The wide range of differences between the devices suggests they should not be used interchangeably.