Comparison of Keratoconus Cone Location of Different Topo/tomographical Parameters


Purpose: To compare the corneal cone location on different maps and instruments, and their agreements, with elevation maps.Methods: In 90 left eyes with bilateral keratoconus, the apex of cone location was determined based on the maximum simulated keratometry (Kmax) location on the anterior sagittal curvature map by Pentacam HR, the maximum curvature on the mean curvature map by ATLAS 9000, most elevated point of the island of positive elevation relative to the best fit sphere on the front and back corneal elevation maps by Pentacam HR, and thinnest point on the thickness map by Pentacam HR and Orbscan, and the thinnest points on pachymetry and epithelial thickness maps by RTVue OCT.Results: There was a significant difference among the location on different maps along the x- and y-axes (p < .001). The lowest agreement with the cone apex on both front and back elevation maps was for the anterior sagittal curvature map and the highest agreement for the Pentacam thickness map. The majority of keratoconus cone apexes were displaced in the inferotemporal direction on the different maps except for the epithelial thickness maps.Conclusions: Despite the variability between different devices and methods; the thickness map on the Pentacam HR showed the highest correlation with the front and back elevation maps, while the RTVue epithelial thickness map showed the poorest correlation. Based on this study, epithelial thickness maps and anterior curvature maps should be utilized with caution to determine the location of the cone.

Publication DOI:
Divisions: College of Health & Life Sciences > School of Optometry > Optometry
College of Health & Life Sciences > School of Optometry > Optometry & Vision Science Research Group (OVSRG)
College of Health & Life Sciences
Additional Information: This is an Accepted Manuscript version of the following article, accepted for publication in Current Eye Research. Mohammad-Reza Sedaghat, Hamed Momeni-Moghaddam, Abbas Azimi Khorasani, Michael W Belin, Naeemeh Monfared, James S. W. Wolffsohn, Maryam Pakdel, Majid Farrokh Ghate & Zahra Hemmatian (2021) Comparison of Keratoconus Cone Location of Different Topo/tomographical Parameters, Current Eye Research. It is deposited under the terms of the Creative Commons Attribution-NonCommercial License (, which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited.
Uncontrolled Keywords: Keratoconus,cone location,curvature map,elevation map,pachymetry map,Ophthalmology,Sensory Systems,Cellular and Molecular Neuroscience
Publication ISSN: 1460-2202
Last Modified: 23 May 2024 07:15
Date Deposited: 26 May 2021 09:38
Full Text Link:
Related URLs: https://www.tan ... 83.2021.1931343 (Publisher URL)
http://www.scop ... tnerID=8YFLogxK (Scopus URL)
PURE Output Type: Article
Published Date: 2021-11
Published Online Date: 2021-05-17
Accepted Date: 2021-05-05
Authors: Sedaghat, Mohammad-reza
Momeni-moghaddam, Hamed
Azimi Khorasani, Abbas
Belin, Michael W
Monfared, Naeemeh
Wolffsohn, James S. W. (ORCID Profile 0000-0003-4673-8927)
Pakdel, Maryam
Farrokh Ghate, Majid
Hemmatian, Zahra


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