Table 2.
Comparison of corneal densitometry (CD) between the SMILE and LASEK groups.
| CD (GSU) | Anterior layer | Central layer | Posterior layer | Total thickness | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 0-2 mm | 2-6 mm | 6-10 mm | 0-2 mm | 2-6 mm | 6-10 mm | 0-2 mm | 2-6 mm | 6-10 mm | 0-2 mm | 2-6 mm | 6-10 mm | ||
| Preoperative | SMILE | 22.95 ± 1.44 | 20.61 ± 1.34 | 20.03 ± 3.43 | 13.7 ± 0.85 | 12.25 ± 0.64 | 12.73 ± 1.88 | 10.83 ± 0.84 | 9.94 ± 0.57 | 11.03 ± 1.39 | 15.89 ± 0.99 | 14.26 ± 0.74 | 14.6 ± 2.17 |
| LASEK | 23.48 ± 1.15 | 20.92 ± 0.98 | 20.61 ± 3.84 | 13.89 ± 0.58 | 12.42 ± 0.49 | 12.86 ± 2 | 10.78 ± 0.87 | 9.89 ± 0.71 | 11.13 ± 1.58 | 16.05 ± 0.7 | 14.4 ± 0.57 | 14.86 ± 2.37 | |
| P-value | 0.053 | 0.201 | 0.451 | 0.209 | 0.157 | 0.764 | 0.807 | 0.687 | 0.743 | 0.375 | 0.316 | 0.583 | |
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| Postoperative month 3 | SMILE | 22.51 ± 1.33 | 20.6 ± 1.1 | 19.77 ± 3.43 | 13.73 ± 0.77 | 12.5 ± 0.63 | 13 ± 2.02 | 10.5 ± 0.78 | 10.07 ± 0.65 | 11.51 ± 1.58 | 15.57 ± 0.82 | 14.39 ± 0.67 | 14.76 ± 2.26 |
| Change | -0.44 ± 1.32 | 0 ± 1.23 | -0.26 ± 1.75 | 0.04 ± 0.88 | 0.25 ± 0.71 | 0.26 ± 0.9 | -0.33 ± 0.99 | 0.13 ± 0.83 | 0.48 ± 0.81 | -0.32 ± 0.98 | 0.13 ± 0.8 | 0.16 ± 1.1 | |
| LASEK | 20.13 ± 1.28 | 18.22 ± 1.25 | 18.4 ± 3.69 | 14.28 ± 0.9 | 12.64 ± 0.62 | 12.83 ± 1.88 | 10.74 ± 0.71 | 10.05 ± 0.57 | 11.4 ± 1.47 | 15.05 ± 0.81 | 13.63 ± 0.66 | 14.21 ± 2.27 | |
| Change | -3.36 ± 1.27# | -2.7 ± 1.16# | -2.2 ± 1.36# | 0.39 ± 0.66# | 0.22 ± 0.45 | -0.02 ± 0.7 | -0.05 ± 1.05 | 0.16 ± 0.83 | 0.27 ± 0.73 | -1.01 ± 0.78# | -0.77 ± 0.63# | -0.65 ± 0.82 | |
| Δchange | -2.92 ± 1.79† | -2.7 ± 1.72† | -1.94 ± 2.37† | 0.35 ± 1.03† | -0.03 ± 0.77 | -0.28 ± 1.08 | 0.28 ± 1.34 | 0.03 ± 1.17 | -0.21 ± 1.04 | -0.68 ± 1.21† | -0.9 ± 0.97† | -0.81 ± 1.35† | |
| 95% CI | (-3.45, -2.38) | (-3.19, -2.20) | (-2.59, -1.29) | (0.03, 0.67) | (-0.27, 0.22) | (-0.62, 0.05) | (-0.14, 0.71) | (-0.32, 0.37) | (-0.53, 0.11) | (-1.05, -0.32) | (-1.19, -0.60) | (-1.21, -0.41) | |
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| Postoperative year 1 | SMILE | 20.01 ± 1.3 | 18.64 ± 1.07 | 18.38 ± 3.05 | 12.47 ± 0.68 | 11.65 ± 0.53 | 12.29 ± 1.76 | 9.55 ± 0.74 | 9.39 ± 0.59 | 10.85 ± 1.39 | 14 ± 0.81 | 13.23 ± 0.64 | 13.84 ± 1.99 |
| Change | -2.94 ± 1.19∗ | -1.97 ± 0.99∗ | -1.66 ± 2.61∗ | -1.23 ± 0.62∗ | -0.6 ± 0.52∗ | -0.44 ± 1.21 | -1.28 ± 0.99∗ | -0.55 ± 0.82∗ | -0.18 ± 0.91 | -1.89 ± 0.8∗ | -1.04 ± 0.67∗ | -0.76 ± 1.5 | |
| LASEK | 17.87 ± 0.98 | 16.51 ± 0.92 | 17.13 ± 3.82 | 12.35 ± 0.48 | 11.37 ± 0.36 | 11.91 ± 1.98 | 9.45 ± 0.63 | 9.1 ± 0.5 | 10.6 ± 1.53 | 13.23 ± 0.57 | 12.32 ± 0.44 | 13.22 ± 2.36 | |
| Change | -5.61 ± 1.31# | -4.41 ± 1.04# | -3.48 ± 1.71# | -1.54 ± 0.65# | -1.05 ± 0.47# | -0.95 ± 0.9# | -1.34 ± 1.02# | -0.79 ± 0.79# | -0.53 ± 0.81 | -2.82 ± 0.83# | -2.08 ± 0.61# | -1.64 ± 1.06# | |
| Δchange | -2.67 ± 1.87† | -2.45 ± 1.3† | -1.82 ± 3.07† | -0.31 ± 0.79† | -0.45 ± 0.59† | -0.5 ± 1.51† | -0.06 ± 1.41 | -0.24 ± 1.14 | -0.35 ± 1.21 | -0.93 ± 1.09† | -1.04 ± 0.77† | -0.88 ± 1.8† | |
| 95% CI | (-3.19, -2.15) | (-2.87, -2.03) | (-2.74, -0.91) | (-0.57, -0.05) | (-0.65, -0.24) | (-0.95, -0.06) | (-0.48, 0.36) | (-0.57, 0.10) | (-0.71, 0.01) | (-1.27, -0.59) | (-1.31, -0.78) | (-1.42, -0.34) | |
|| p < 0.05, significant difference in preoperative values between the SMILE and LASEK groups. ∗p < 0.05, significantly different from the preoperative values in the SMILE group. #p < 0.05, significantly different from the preoperative values in the LASEK group. †p < 0.05, greater change in the LASEK group than in the SMILE group. ΔChange = difference in the changes between the two groups; CI = confidence interval; GSU = grayscale units.