Repeatability of topographic corneal thickness in keratoconus comparing Visante™ OCT and Oculus Pentacam HR® topographer

TitleRepeatability of topographic corneal thickness in keratoconus comparing Visante™ OCT and Oculus Pentacam HR® topographer
Publication TypeJournal Article
Year of Publication2017
AuthorsOtchere, H., and L. Sorbara
JournalContact Lens and Anterior Eye
Keywordsadult, Article, central corneal thickness, clinical article, controlled study, Cornea, cornea thickness, corneal pachymetry, Corneal Topography, devices, diagnostic imaging, equipment design, female, human, Humans, keratoconus, keratometry, male, measurement repeatability, middle aged, ophthalmic camera, Optical Coherence, Optical coherence tomography, optical coherence tomography device, pathology, post hoc analysis, priority journal, procedures, Prospective Studies, prospective study, Repeatability, reproducibility, Reproducibility of Results, Tomography, Topographic corneal thickness, young adult

Purpose To assess the repeatability and reproducibility of Visante™ OCT and Oculus Pentacam HR® in measuring central (CCT) and topographic corneal thickness (TCT) along the principle meridians in keratoconus (KC) corneae. Method Twenty participants diagnosed with KC were recruited. There were two study visits. On the first study visit, two repeated corneal thickness measurements were obtained with each instrument. Measurements were repeated at least 48hrs later in the same order. TCT were recorded in the 90, 180, 45 and 135 meridians at 1mm intervals across 8mm chord. Results Mean CCT for Visante™ OCT was 484.97 ± 43.14 μm (range: 484.84–486.09) and Oculus Pentacam HR® was 478.86 ± 45.31 μm (range: 477.20–480.53). No significant difference in TCT between the two visits (p = 0.54) and measurements (p = 0.63) for Visante™ OCT. For Oculus Pentacam HR®, no significant difference was found for each visit (p = 0.18) but differences existed in the measurements outside of the central region (p = 0.001). Tukey post-hoc analysis shows the differences (p ˂ 0.05) were found in the +1 and +4 (supero-temporal) locations in the 135 meridian. Significant differences were found comparing the two instruments, (p < 0.05). Bland Altman plots were used to demonstrate the differences between the two instruments and indicate their limits of agreement. Conclusion Both instruments gave repeatable measurements as no significant differences were found in most locations in all meridians. Comparing the two instruments, they were not reproducible in all locations. © 2017 British Contact Lens Association