title: Reliability of manual measurements of corneal thickness obtained from healthy canine eyes using spectral-domain optical coherence tomography (SD-OCT).
abstract: The purpose of this study was to manually measure corneal thickness in canine eyes using a spectral-domain optical coherence tomography (SD-OCT) device and to assess intra- and inter-observer reliability of this technique. Twenty healthy dogs with a mean age of 4.7 y were examined. A 6-mm corneal pachymetry protocol was carried out by 1 operator using 1 SD-OCT device in both eyes of each animal. Measurements were obtained manually and in duplicate by 2 independent investigators (> 24 h apart), using the built-in caliper function. Measurements included epithelial thickness (ET), non-epithelial thickness (NET), and central corneal thickness (CCT). The overall mean ET, NET, and CCT for all eyes examined were 72.3 ± 4.6 μm, 538.9 ± 42.5 μm, and 611.2 ± 40.3 μm, respectively. There was no significant difference in ET, NET, or CCT based on the eye examined [oculus dexter (OD) versus oculus sinister (OS)], age, or gender of the animal. There was no significant difference in replicate measurements of ET, NET, or CCT done by the same operator, although a small but significant difference was noted between operators for ET measurements only. The mean difference in ET between operators was 0.6 μm (P = 0.03). The coefficient of variation ranged from 0.5% to 9.27% and intraclass correlation coefficient ranged from 0.35 to 0.97. Based on these results, manual measurements of corneal thickness in canine eyes using a portable SD-OCT device provided ET, NET, and CCT measurements with clinically acceptable intra- and inter-observer reliability.
authors: Department of Clinical Sciences, Tufts Cummings School of Veterinary Medicine, North Grafton, Massachusetts 01536, USA.
authors: Anthony F
authors: AF
authors: Alario
authors: Department of Clinical Sciences, Tufts Cummings School of Veterinary Medicine, North Grafton, Massachusetts 01536, USA.
authors: Christopher G
authors: CG
authors: Pirie
mesh_terms: D000818:Animals; D003315:Cornea / Q000033:anatomy & histology*; D004285:Dogs / Q000033:anatomy & histology*; D005260:Female; D008297:Male; D015588:Observer Variation; D015203:Reproducibility of Results; D041623:Tomography, Optical Coherence / Q000379:methods / Q000706:statistics & numerical data / Q000662:veterinary*