Table 1.
Comparisons of the preoperative corneal cylindrical errors between simulated keratometry (simKa), true net power (TNPa), and total corneal refractive power (TCRPa) from 1 mm to 8 mm. All values were adjusted for the corneal plane using a vertex distance of 12 mm.
| Vector means | Difference | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| simKa | TNPa | TCRPa | TCRPa versus simKa | TCRPa versus TNPa | simKa versus TNPa | ||||
| Magnitude∗ | |Angle|∗∗ | Magnitude∗ | |Angle|∗∗ | Magnitude∗ | |Angle|∗∗ | ||||
| 1 mm | (0.94 ± 0.56) × 91.2 | (0.71 ± 0.57) × 89.7 | (0.74 ± 0.57) × 89.9 | 0.20 ± 0.20 | 6.9 ± 12.2 | 0.03 ± 0.13 | 1.1 ± 4.7 | 0.23 ± 0.15 | 6.9 ± 12.2 |
| 2 mm | (1.11 ± 0.57) × 91.3 | (0.88 ± 0.57) × 90.3 | (0.93 ± 0.58) × 90.6 | 0.18 ± 0.16 | 4.6 ± 9.4 | 0.05 ± 0.18 | 1.5 ± 8.2 | 0.24 ± 0.15 | 5.0 ± 11.0 |
| 3 mm | (1.17 ± 0.55) × 91.6 | (0.97 ± 0.54) × 91.7 | (1.02 ± 0.55) × 91.9 | 0.14 ± 0.14 | 3.1 ± 6.0 | 0.05 ± 0.13 | 0.8 ± 5.1 | 0.20 ± 0.09 | 2.8 ± 4.4 |
| 4 mm | (1.19 ± 0.56) × 92.4 | (1.02 ± 0.53) × 93.1 | (1.11 ± 0.57) × 93.1 | 0.09 ± 0.13 | 2.9 ± 5.5 | 0.08 ± 0.10 | 0.8 ± 5.0 | 0.17 ± 0.09 | 2.6 ± 4.0 |
| 5 mm | (1.15 ± 0.57) × 94 | (1.01 ± 0.57) × 94.6 | (1.13 ± 0.60) × 94.9 | 0.04 ± 0.14 | 3.1 ± 5.8 | 0.13 ± 0.19 | 0.8 ± 4.1 | 0.14 ± 0.15 | 2.6 ± 4.7 |
| 6 mm | (1.05 ± 0.59) × 96.3 | (0.98 ± 0.57) × 96.6 | (1.12 ± 0.65) × 97.1 | 0.07 ± 0.16 | 3.3 ± 7.3 | 0.14 ± 0.14 | 1.2 ± 3.3 | 0.07 ± 0.11 | 2.7 ± 6.4 |
| 7 mm | (0.95 ± 0.60) × 98.2 | (0.95 ± 0.58) × 97.2 | (1.12 ± 0.69) × 97.9 | 0.16 ± 0.36 | 3.7 ± 8.2 | 0.17 ± 0.17 | 1.6 ± 4.1 | 0.03 ± 0.10 | 3.5 ± 7.2 |
| 8 mm | (0.91 ± 0.61) × 98.2 | (1.01 ± 0.61) × 95.7 | (1.25 ± 0.77) × 96.5 | 0.53 ± 0.98 | 5.3 ± 10.9 | 0.25 ± 0.26 | 2.5 ± 9.1 | 0.13 ± 0.11 | 4.4 ± 8.0 |
∗Magnitude represented the magnitude of the vector difference.
∗∗|Angle| was defined as the mean absolute values of the arithmetic difference between the axis of two corneal astigmatisms. It was defined always to be an acute angle.