Comparison between Pentacam‐HR and optical coherence tomographycentral corneal thickness measurements in healthy feline eyes

Objectives To measure the central corneal thickness ( CCT ) in healthy feline eyes with Scheimpflug imaging (Pentacam, Pentacam ® ‐ HR ) and to compare these values with those obtained with spectral‐domain optical coherence tomography (OCT, Optovue ® iV ue). Animals studied Thirty one sedated Domestic Short‐haired cats. Procedures Two repeated CCT measurements were obtained from both eyes using Pentacam measured at the pupil center and corneal apex ( CCT pupil and CCT apex ) and using SD ‐ OCT ( CCT OCT ). Agreement between the imaging modalities for CCT and intradevice repeatability was evaluated with Bland–Altman analysis. Mixed modeling was used to test for a difference between methods. Results The calculated mean ±  SD CCT was CCT OCT  = 584.93 ± 39.05 μm, CCT pupil  = 608.25 ± 47.26 μm, and CCT apex  = 606.41 ± 44.18 μm. There was a statistically significant difference between CCT OCT vs. CCT pupil ( P  < 0.0007) and CCT OCT vs. CCT apex ( P  < 0.0003) ( n  = 59 eyes). The 95% limits of agreement (LoA) for CCT OCT vs. CCT pupil was (–89.57 μm, 40.04 μm) and for CCT OCT vs. CCT apex was (−79.62 μm, 33.79 μm) ( n  = 59 eyes). 95% LoA between repeated CCT measurements by SD ‐ OCT was (−10.23 μm, 9.32 μm) and by Pentacam was (−22.66 μm, 18.30 μm) at pupil and (−15.81 μm, 16.17 μm) at corneal apex ( n  = 11 eyes). Conclusions SD ‐ OCT and Pentacam provide excellent CCT measurement repeatability. Pentacam apex is our recommended clinical setting for use of the Pentacam. The level of agreement between SD ‐ OCT and Pentacam for CCT is good.