Short-term variation of central corneal thickness and axial anterior chamber depth of healthy eyes using Scheimpflug photography via the Oculus Pentacam

The purpose of this study was to investigate short-term variation and intra-subject repeatability of human central corneal thickness (CCT) and axial anterior chamber depth (AACD) measurements obtained using the Oculus Pentacam. Forty consecutive images of the right eye of the anterior segment of 10 young and healthy individuals were measured with the Pentacam. Measurements of CCT and AACD were obtained from these images and means, standard deviations, variances and repeatability of the measurements were investigated. Both parameters (CCT and AACD) showed small variation with good or excellent repeatability for all eyes. The inter-subject or overall means and standard deviations for CCT and AACD of the 10 right eyes were 0.555 +/- 0.05 millimeters (or 555 +/- 50 microns) and 3.206 +/- 0.04 millimeters, respectively. The individual or intra-subject averages for samples of CCT and AACD measurements are also provided in this paper. Univariate normality of the data was explored with Kolmogorov-Smirnov, Lilliefors and ShapiroWilks tests and we found that generally the data was normally distributed although there were some exceptions. Based on the results of this study, the Oculus Pentacam appears to provide repeatable and reliable measures for both CCT and AACD in young, normal eyes. Further research is, however, needed to determine short-term variation and repeatability of CCT and AACD with the Pentacam in more complicated eyes with, say, corneal scarring or ectasia or where refractive surgery may be an issue.