Comparisons of refractive outcomes between the SMILE and FS-LASIK groups
| Parameters | SMILE group | FS-LASIK group | P values | ||
| Mean | SD | Mean | SD | ||
| LogMAR UDVA | −0.05 | 0.08 | −0.02 | 0.09 | 0.069 |
| Sphere (D) | −0.03 | 0.50 | −0.16 | 0.69 | 0.306 |
| Cylinder (D) | −0.21 | 0.25 | −0.24 | 0.32 | 0.899 |
| Spherical equivalent | −0.14 | 0.49 | −0.28 | 0.65 | 0.317 |
| LogMAR CDVA | −0.11 | 0.07 | −0.08 | 0.08 | 0.058 |
| Axis length (mm) | 26.05 | 1.08 | 26.30 | 1.08 | 0.107 |
| The efficacy index | 1.05 | 0.19 | 1.01 | 0.21 | 0.352 |
| The safety index | 1.19 | 0.17 | 1.15 | 0.21 | 0.307 |
| TIA | 0.94 | 0.63 | 1.01 | 0.87 | 0.992 |
| SIA | 0.90 | 0.58 | 1.01 | 0.91 | 0.802 |
| DV | 0.21 | 0.24 | 0.24 | 0.32 | 0.637 |
| CI | 0.98 | 0.26 | 1.00 | 0.45 | 0.276 |
| MofE | 0.04 | 0.23 | 0.01 | 0.24 | 0.711 |
| AofE | −0.29 | 1.37 | 0.16 | 1.48 | 0.148 |
| IOS | 0.27 | 0.32 | 0.38 | 0.55 | 0.671 |
| FI | 0.60 | 0.76 | 0.73 | 0.75 | 0.345 |
AofE, angle of error; CDVA, corrected distance visualacuity; CI, correction index; DV, difference vector; FI, flattening index; FS-LASIK,femtosecond laser-assisted laser in situ keratomileusis; IOS, index of success; MofE, magnitude of error; SIA，surgically induced astigmatism; SMILE, smallincision lenticule extraction; TIA, target-induced astigmatism; UDVA, uncorrected distance visual acuity.