Vector analysis of astigmatic correction at 1 and 3 months after small-incision lenticule extraction (SMILE) and femtosecond-assisted laser in situ keratomileusis (LASIK) using Alpins method
| SMILE | LASIK | p Value* | |||
|---|---|---|---|---|---|
| TIA | Arithmetic mean±SD (D) | 0.95±0.61 | 1.19±0.84 | 0.091 | |
| Range (D) | 0.93 to 0.97 | 1.16 to 1.22 | |||
| SIA | 1 month | Arithmetic mean±SD (D) | 0.88±0.56 | 1.20±0.87 | 0.023 |
| Range (D) | 0.86 to 0.90 | 1.17 to 1.23 | |||
| 3 months | Arithmetic mean±SD (D) | 0.89±0.56 | 1.22±0.86 | 0.018 | |
| Range (D) | 0.87 to 0.91 | 1.19 to 1.25 | |||
| p Value† | 0.678 | 0.122 | |||
| DV | 1 month | Arithmetic mean±SD (D) | 0.27±0.31 | 0.07±0.15 | <0.001 |
| Range (D) | 0.26 to 0.28 | 0.07 to 0.08 | |||
| 3 months | Arithmetic mean±SD (D) | 0.24±0.31 | 0.06±0.14 | <0.001 | |
| Range (D) | 0.23 to 0.25 | 0.06 to 0.07 | |||
| p Value† | 0.225 | 0.583 | |||
| ME | 1 month | Arithmetic mean±SD (D) | −0.07±0.32 | 0.01±0.12 | 0.070 |
| Range (D) | −0.08 to −0.06 | 0.01 to 0.02 | |||
| 3 months | Arithmetic mean±SD (D) | −0.06±0.29 | 0.03±0.12 | 0.025 | |
| Range (D) | −0.07 to −0.05 | 0.03 to 0.04 | |||
| p Value† | 0.678 | 0.122 | |||
| AE | 1 month | Arithmetic mean±SD (°) | −0.85±35.65 | 2.09±21.11 | 0.596 |
| Range (°) | −2.14 to 0.45 | 1.37 to 2.82 | |||
| 3 months | Arithmetic mean±SD (D) | −0.93±32.45 | 2.40±21.29 | 0.777 | |
| Range (D) | −0.25 to 2.11 | 1.67 to 3.13 | |||
| p Value† | 0.289 | 0.643 | |||
| Absolute AE | 1 month | Arithmetic mean±SD (°) | 24.07±26.10 | 12.21±17.28 | 0.005 |
| Range (°) | 23.12 to 25.01 | 11.62 to 12.80 | |||
| 3 months | Arithmetic mean±SD (D) | 21.92±23.76 | 12.25±17.51 | 0.016 | |
| Range (D) | 21.05 to 22.78 | 11.65 to 12.85 | |||
| p Value† | 0.195 | 0.953 | |||
| CI | 1 month | Geometric mean±SD | 0.93±0.48 | 1.00±0.11 | – |
| Range | 0.91 to 0.95 | 1.00 to 1.01 | |||
| 3 months | Geometric mean±SD | 0.94±0.44 | 1.04±0.17 | – | |
| Range | 0.92 to 0.95 | 1.03 to 1.05 | |||
| CA | 1 month | Geometric mean±SD | 1.07±0.65 | 1.00±0.11 | – |
| Range | 1.05 to 1.10 | 0.99 to 1.00 | |||
| 3 months | Geometric mean±SD | 1.07±0.76 | 0.96±0.10 | – | |
| Range | 1.04 to 1.09 | 0.96 to 0.97 | |||
| FI | 1 month | Geometric mean±SD | 0.69±0.86 | 0.67±0.70 | – |
| Range | 0.66 to 0.72 | 0.65 to 0.70 | |||
| 3 months | Geometric mean±SD | 0.69±0.86 | 0.71±0.77 | – | |
| Range | 0.66 to 0.72 | 0.68 to 0.73 | |||
| IS | 1 month | Geometric mean±SD | 0.18±0.70 | 0.01±0.18 | – |
| Range | 0.16 to 0.21 | 0.01 to 0.02 | |||
| 3 months | Geometric mean±SD | 0.14±0.64 | 0.01±0.19 | – | |
| Range | 0.11 to 0.16 | 0.01 to 0.02 |
*Comparison between SMILE and LASIK. p<0.05=statistically significant.
†Comparison between 1-month and 3-month results. p<0.05=statistically significant.
AE, angle of error; CA, coefficient of adjustment; CI, correction index; DV, difference vector; FI, flattening index; IS, index of success; ME, magnitude of error; SIA, surgically induced astigmatism; TIA, target-induced astigmatism.