Table 3.
Comparison of preoperative characteristics of the eyes with and without regression
| Characteristics | Mean | P value | |
|---|---|---|---|
| No regression (n = 237) |
Regression (n = 56) |
||
| Age (y) | 31.4 | 31.8 | 0.72 |
| Thickness(μm) | 535.7 | 529.7 | 0.21 |
| Irregularity 3 (mm) | 0.99 | 1.16 | 0.001 |
| Irregularity 5 (mm) | 1.36 | 1.61 | 0.001 |
| Diff posterior (mm) | 0.02 | 0.02 | 0.34 |
| SimK (D) | 1.06 | 1.69 | 0.001 |
| Eye movement (mm) | 3.80 | 4.56 | 0.07 |
| Sphere value (D) | 3.07 | 5.17 | 0.001 |
| Astigmatism value (D) | 1.09 | 2.05 | 0.001 |
PRK Photorefractive keratectomy, Diff posterior: steepest posterior point difference from Best fit sphere, Sim k astigmatism: simulated keratometry astigmatism, P value: Independent T test