Corneal Pachymetry measured with Pentacam and CorvisST in Normal and Keratoconic Eyes

Purpose: To evaluate the agreement of pachymetry data provided by a new instrument to measure intraocular pressure (IOP) and the corneal biomechanical response with the values provided by Pentacam in healthy and keratoconic eyes. Methods: Fifty-four right eyes from 54 healthy patients (32 females, 22 males) and 82 eyes from 43 keratoconus patients (20 females, 23 males) were included in the study. All patients were evaluated with Pentacam and CorvisST (Oculus, Wetzlar, Germany) in random order in the same session. CorvisCCT was compared to Pentacam pachymetry in at the corneal center (PentacamCCT) and at the thinnest point (PentacamMinCT). Results: Average pachymetry provided by CorvisST was 534 ± 34 microns in the healthy population and 476 ± 56 microns in the population with keratoconus. Pachymetric values obtained with Pentacam were highly correlated between them as well as with the Corvis value in both groups, but the correlation coefficients were higher in the healthy group. Conclusion: Corvis pachymetry can be used interchangeably with Pentacam thinnest point pachymetry in healthy corneas. However, in keratoconic corneas, the difference between both parameters will be higher as the disease progresses and increases the difference between Pentacam pachymetry at cornea center and at the thinnest point.