Comparison of Corneal Densitometry and Visual Quality after Small Incision Lenticule Extraction (SMILE) and Laser Epithelial Keratomileusis (LASEK): One-Year Comparative Study
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
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)
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)
||, significant difference in preoperative values between the SMILE and LASEK groups. , significantly different from the preoperative values in the SMILE group. #, significantly different from the preoperative values in the LASEK group. †, 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.
