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Updated: May 29, 2026
Full-Field Optical Coherence Microscopy for Histology-Like Analysis of Stromal Features in Corneal Grafts
Published on: October 21, 2022
Central corneal thickness measurements: using an ultrasonic instrument and 4 optical instruments
Ravaughn Williams1, Barbara A Fink, P Ewen King-Smith
1College of Optometry, The Ohio State University, Columbus, OH 43210-1280, USA.
Purpose:
Both between-session and within-session repeatability were determined for measurement of corneal thickness with the following techniques: ultrasound pachymetry (UP), confocal microscopy (CS), Orbscan pachymetry (ORB), spectral oscillation interferometry (SOI), and optical coherence tomography (OCT).
Methods:
The right eyes of 20 normal subjects were tested on 2 different days. For each session, 2 central corneal thickness measurements were determined using the ConfoScan 3 microscope, the Orbscan system, and the Stratus OCT system; 5 measurements were found with the Sonogage ultrasound pachymeter; and between 2 and 10 measurements were found with the SOI system.
Results:
This study showed that SOI had the best repeatability, whereas CS had the worst repeatability for both within-session and between-session repeatability. Based on 95% limits of agreement (LoA), the within-session repeatability can be ranked as: (1) SOI; (2) UP; (3) OCT; (4) Orbscan pachymetry; and (5) CS. SOI had a bias of 0.13 and 95% LoA of -1.07 to 1.33, whereas UP had a bias of -0.98 and 95% LoA of -7.35 to 5.40. The between-session repeatability of the instruments can be ranked as: (1) SOI; (2) OCT; (3) UP; (4) Orbscan pachymetry; and (5) CS. Of the optical methods, SOI had the best repeatability with a bias of 1.26 and 95% LoA of -6.14 to 8.66, followed by OCT with a bias of 0.75 and 95% LoA of -16.22 to 17.27.
Conclusions:
Of the 4 instruments that are commercially available, the UP was the most repeatable for within sessions, and the OCT was the most repeatable for between sessions.
