Abstract
Purpose: :
To compare a combined Scheimpflug and Placido (Galilei, Ziemer) to a Scheimpflug device (Pentacam, Oculus) in eyes with keratoconus.
Methods: :
In a prospective clinical trial, keratometry values (Ks, steep meridian; Kf, flat meridian), thinnest corneal thickness (TCT) and anterior chamber depth (ACD) obtained with the Galilei were compared to the Pentacam in keratoconus eyes. Three measurements were performed with both devices for each eye. The results were compared using Wilcoxon test, Bland Altman and correlation analysis. To assess reproducibility and accuracy of measurements, means of standard deviations (SD) of measurement values for each eye and their SD’s were evaluated.
Results: :
45 eyes with keratoconus of 39 patients were included in this trial. The Galilei revealed a mean Ks of 45.90 ± 2.85 D compared to 44.55 ± 3.17 D found with the Pentacam, a mean Kf of 43.62 ± 2.51 D vs. 46.04 ± 3.75 D, a mean TCT of 486 ± 39 µm vs. 481 ± 39 µm and a mean ACD of 3.22 ± 0.38 mm vs. 3.17 ± 0.41 mm. Correlation of all parameters was significant between both devices. A significant higher reproducibility was found for the Pentacam compared to the Galilei regarding Ks, TCT and ACD (p<0.01, each), whereas no significant difference in repeat accuracy was found for Kf (p>0.05).
Conclusions: :
Galilei revealed a significant correlation to Pentacam for keratometry, pachymetry and anterior chamber depth measurements in eyes with keratoconus, however measurement reproducibility was lower with the Galilei.
Keywords: cornea: clinical science • topography • keratoconus