Allison E Wolfel1, Samantha L Pederson1, Allison M Cleymaet1, Ann M Hess2, Kate S Freeman1. 1. Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, 80523, USA. 2. Department of Statistics, College of Natural Sciences, Colorado State University, Fort Collins, CO, 80523, USA.
Abstract
OBJECTIVE: To compare central corneal thickness (CCT) values in canine eyes using Pentacam-HR® Scheimpflug imaging (Pentacam), Optovue® iVue spectral-domain optical coherence tomography (SD-OCT), and high-resolution ultrasound biomicroscopy (UBM) and generate normative canine Pentacam CCT values. ANIMALS STUDIED: Twenty-four client-owned dogs (37 eyes) with nondiseased cornea(s) presenting to the Colorado State University Veterinary Teaching Hospital. PROCEDURES: Corneal images were acquired via Pentacam, SD-OCT, and UBM in the listed order. Machine-calculated values of CCT from Pentacam and SD-OCT were compared to operator-measured values from UBM. Bland-Altman analysis was performed to evaluate agreement between instruments. RESULTS: Mean CCT ± SD measured by Pentacam was 629.73 ± 64.57 μm, by SD-OCT was 610.56 ± 57.48 μm, and by UBM was 689.77 ± 55.93 μm. On average, Pentacam CCT was 19.17 ± 32.90 μm (3%) thicker than SD-OCT and 65.12 ± 44.52 μm (10.3%) thinner than UBM. SD-OCT was on average 82.47 μm (13.5% ) thinner than UBM. The 95% limits of agreement were (-45.31, 83.65), (-152.38, 22.13), and (-126.674, -38.270) for Pentacam vs. SD-OCT, Pentacam vs. UBM, and SD-OCT vs. UBM respectively. All differences were statistically significant (P < 0.01). CONCLUSIONS: Considering there is an average of 7.5% normal diurnal variation in canine CCT, a 3.0% difference between Pentacam and SD-OCT values is likely not clinically relevant. However, Pentacam measurements were both statistically and clinically significantly different from UBM and SD-OCT measurements.
OBJECTIVE: To compare central corneal thickness (CCT) values in canine eyes using Pentacam-HR® Scheimpflug imaging (Pentacam), Optovue® iVue spectral-domain optical coherence tomography (SD-OCT), and high-resolution ultrasound biomicroscopy (UBM) and generate normative caninePentacam CCT values. ANIMALS STUDIED: Twenty-four client-owned dogs (37 eyes) with nondiseased cornea(s) presenting to the Colorado State University Veterinary Teaching Hospital. PROCEDURES: Corneal images were acquired via Pentacam, SD-OCT, and UBM in the listed order. Machine-calculated values of CCT from Pentacam and SD-OCT were compared to operator-measured values from UBM. Bland-Altman analysis was performed to evaluate agreement between instruments. RESULTS: Mean CCT ± SD measured by Pentacam was 629.73 ± 64.57 μm, by SD-OCT was 610.56 ± 57.48 μm, and by UBM was 689.77 ± 55.93 μm. On average, Pentacam CCT was 19.17 ± 32.90 μm (3%) thicker than SD-OCT and 65.12 ± 44.52 μm (10.3%) thinner than UBM. SD-OCT was on average 82.47 μm (13.5% ) thinner than UBM. The 95% limits of agreement were (-45.31, 83.65), (-152.38, 22.13), and (-126.674, -38.270) for Pentacam vs. SD-OCT, Pentacam vs. UBM, and SD-OCT vs. UBM respectively. All differences were statistically significant (P < 0.01). CONCLUSIONS: Considering there is an average of 7.5% normal diurnal variation in canine CCT, a 3.0% difference between Pentacam and SD-OCT values is likely not clinically relevant. However, Pentacam measurements were both statistically and clinically significantly different from UBM and SD-OCT measurements.
Authors: Kelly E Knickelbein; Mary E Lassaline; Soohyun Kim; Machal S Scharbrough; Sara M Thomasy Journal: Vet Ophthalmol Date: 2022-01-27 Impact factor: 1.444