Research Article

Corneal Astigmatism Measurements Comparison among Ray-Tracing Aberrometry, Partial Coherence Interferometry, and Scheimpflug Imaging System

Table 4

Difference between the wavefront corneal astigmatism and simulated corneal astigmatism measurements obtained using iTrace.

Wavefront astigmatismSimulated astigmatismDifference (W − S) ± SE

Astigmatism magnitude (D)2.00 ± 0.871.89 ± 0.840.10 ± 0.02<0.001
Astigmatism cardinal0.75 ± 1.880.74 ± 1.780.01 ± 0.020.687
Astigmatism oblique−0.15 ± 0.83−0.11 ± 0.78−0.04 ± 0.010.001

D = diopters; S = simulated astigmatism; SE = standard error; W = wavefront astigmatism. Paired two-tailed t-test. Statistically significant at the 5% level.