Abstract
Purpose: :
To evaluate the reproducibility of Pentacam HR and Orbscan II system in healthy and keratoconic corneas.
Methods: :
One hundred healthy subjects and ninety three keratoconus patients were enrolled in this study. Keratoconus patients were divided into 4 groups according to Amsler-Krumeich classification. An experienced observer acquired two consecutive measurements using Pentacam HR and Orbscan II from each eye. The repeatability data were analyzed using repeated measures Two-way ANOVA test. The correlation between first and second readings were evaluated using Pearson correlation test. p<0.05 was considered statistically significant.
Results: :
The mean age of the control subjects were 31.5±8patients were 27.1±9 years. Mean keratometry, minimum pachymetry, central corneal thickness, anterior best fit sphere, maximum anterior elevation was significantly different between two consecutive Pentacam HR measurements. Mean keratometry, 5 mm astigmatic power, posterior keratometry, minimum pachymetry, central corneal thickness, anterior/posterior best fit sphere, maximum anterior/posterior elevation was significantly different between two consecutive Orbscan II measurements. Pentacam HR produced a better reproducibility in keratoconic corneas. The correlation coefficients were higher amongst Pentacam HR readings.
Conclusions: :
Both devices showed a good intraobserver correlation. However, Pentacam HR showed better reproducibility especially in elevation and pachymetric values when compared to that of Orbscan II.
Keywords: keratoconus • imaging/image analysis: clinical • topography