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

Table 3

Comparison of corneal astigmatism values between devices.

Device

Correlation between devices ()

Mean difference (D) ± SD

95% CI

95% of LoA spread (D)

Magnitude

Cardinal component

Oblique component

Magnitude

Cardinal component

Oblique component

Magnitude

Cardinal component

Oblique component

Magnitude

Cardinal component

Oblique component

IOLMaster vs. iTrace

0.853 (<0.0001)

0.965 (<0.0001)

0.920 (<0.0001)

0.03 ± 0.47

−0.09 ± 0.48

0.08 ± 0.34

−0.07, 0.13

−0.19, 0.01

0.01, 0.15

1.84

1.89

1.32

IOLMaster vs. Pentacam

0.870 (<0.0001)

0.957 (<0.0001)

0.839 (<0.0001)

0.05 ± 0.45

0.07 ± 0.53

0.00 ± 0.50

−0.04, 0.15

−0.04, 0.18

−0.10, 0.11

1.77

2.08

1.97

iTrace vs. Pentacam

0.881 (<0.0001)

0.967 (<0.0001)

0.868 (<0.0001)

0.02 ± 0.42

0.16 ± 0.46

−0.08 ± 0.45

−0.07, 0.11

0.07, 0.26

−0.17, 0.01

1.66

1.78

1.76

CI = confidence interval; D = diopters; LoA = limit of agreement; SD = standard deviation.