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

Abstract

OBJECTIVES: To measure the central corneal thickness (CCT) in healthy feline eyes with Scheimpflug imaging (Pentacam, Pentacam(&#xae;) -HR) and to compare these values with those obtained with spectral-domain optical coherence tomography (OCT, Optovue(&#xae;) iVue). 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 (CCTpupil and CCTapex ) and using SD-OCT (CCTOCT ). 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&#xa0;&#xb1;&#xa0;SD CCT was CCTOCT &#xa0;=&#xa0;584.93&#xa0;&#xb1;&#xa0;39.05&#xa0;&#x3bc;m, CCTpupil &#xa0;=&#xa0;608.25&#xa0;&#xb1;&#xa0;47.26&#xa0;&#x3bc;m, and CCTapex &#xa0;=&#xa0;606.41&#xa0;&#xb1;&#xa0;44.18&#xa0;&#x3bc;m. There was a statistically significant difference between CCTOCT vs. CCTpupil (P&#xa0;<&#xa0;0.0007) and CCTOCT vs. CCTapex (P&#xa0;<&#xa0;0.0003) (n&#xa0;=&#xa0;59 eyes). The 95% limits of agreement (LoA) for CCTOCT vs. CCTpupil was (-89.57&#xa0;&#x3bc;m, 40.04&#xa0;&#x3bc;m) and for CCTOCT vs. CCTapex was (-79.62&#xa0;&#x3bc;m, 33.79&#xa0;&#x3bc;m) (n&#xa0;=&#xa0;59 eyes). 95% LoA between repeated CCT measurements by SD-OCT was (-10.23&#xa0;&#x3bc;m, 9.32&#xa0;&#x3bc;m) and by Pentacam was (-22.66&#xa0;&#x3bc;m, 18.30&#xa0;&#x3bc;m) at pupil and (-15.81&#xa0;&#x3bc;m, 16.17&#xa0;&#x3bc;m) at corneal apex (n&#xa0;=&#xa0;11 eyes). CONCLUSIONS: SD-OCT and Pentacam provide excellent CCT measurement repeatability. Pentacamapex is our recommended clinical setting for use of the Pentacam. The level of agreement between SD-OCT and Pentacam for CCT is good.