Comparison of central corneal thickness measurements of five different devices with ultrasound pachymetry in healthy eyes

Abstract

Objectives: Several methods of measuring central corneal thickness (CCT) have been compared, however, the data are still limited and conflicting. The aim of this study was to determine the agreement of CCT measurements performed in healthy eyes using ultrasound pachymetry (USP), non-contact tono/pachymetry, specular microscopy, biometry, Scheimpflug-based corneal topography, and optical coherence tomography (OCT). Methods: All of the participants underwent a complete ophthalmological examination. The CCT of all of the eyes included was measured using 6 different methods. The agreement between the methods was analyzed using the mean difference and Bland-Altman analysis based on a 95% limits of agreement. Results: A total of 64 patients with a mean age of 40.96±14.52 years (range: 20-78 years) were included in the study. The mean CCT value was 552.10±35.65 µm, 550.40±35.55 µm, 554.67±35.49 µm, 545.39±34.21 µm, 546.25±35.49 µm, and 552.64±33.59 µm using USP, non-contact tono/pachymetry, non-contact specular microscopy, biometry, Scheimpflugbased corneal topography, and OCT, respectively. The bias values determined by Bland-Altman plots were -1.70, -2.56, 6.71, 5.85, and -0.53 for tono/pachymetry, specular microscopy, biometry, topography, and OCT, respectively. OCT demonstrated the lowest bias compared to USP. The overall intraclass correlation coefficient was 0.961 (range: 0.945-0.974) with a 95% confidence interval. Conclusion: All of the CCT measurements obtained using non-contact tono/pachymetry, non-contact specular microscopy, biometry, Scheimpflug-based corneal topography, and OCT were consistent with the USP measurements of healthy controls. Larger prospective studies to determine the interchangeability of different methods for CCT measurements in pathological conditions are warranted.

Agreement of Two Biometers for Central Corneal Thickness Measurement in High Myopia Patients

“…It is important to determine the discrepancies between devices. 10 A previous study showed that CCT measurements in healthy individuals using ultrasonic pachymetry and optical instruments are not directly interchangeable. 7 Another study by Omoto et al revealed moderate agreement in CCT measurement between two optical biometers using SS-OCT. 11 This study aims to compare the agreement between SS-OCT and the Scheimp ug camera in CCT measurement in patients with high myopia.…”