Simultaneous versus Sequential Accelerated Corneal Collagen Cross-Linking and Wave Front Guided PRK for Treatment of Keratoconus: Objective and Subjective Evaluation
Table 4
Preoperative and postoperative topographical (Pentacam) parameters (mean ± SD) in the 2 studied groups 6 months and 12 months following the full procedure.
Measure
Group
Preoperative measure
6 months
12 months
; repeated measure ANOVA
; preoperative versus 6 m
; preoperative versus 12 m
; 6 m versus 12 m
(D)
G1
43.3 ± 1.77
41.1 ± 1.33
41.0 ± 1.31
<0.001
<0.001
<0.001
0.91
G2
42.9 ± 1.91
40.8 ± 1.39
40.9 ± 1.40
<0.001
<0.001
<0.001
0.88
0.23
0.55
0.31
—
—
—
—
(D)
G1
45.9 ± 2.45
42.5 ± 1.45
42.1 ± 1.44
<0.001
<0.001
<0.001
0.92
G2
45.4 ± 1.83
41.7 ± 1.62
41.8 ± 1.63
<0.001
<0.001
<0.001
0.79
0.11
0.37
0.42
—
—
—
—
max (D)
G1
49.1 ± 4.1
46.2 ± 4.2
45.8 ± 4.4
<0.001
<0.001
<0.001
0.54
G2
48.3 ± 5.4
44.9 ± 5.5
45.2 ± 5.3
<0.001
<0.001
<0.001
0.78
0.88
0.71
0.64
—
—
—
—
G1
−0.47 ± 0.39
−0.29 ± 0.31
−0.28 ± 0.33
<0.001
<0.001
<0.001
0.77
G2
−0.45 ± 0.41
−0.27 ± 0.33
−0.27 ± 0.34
<0.001
<0.001
<0.001
0.64
0.76
0.44
0.54
—
—
—
—
MCT
G1
466 ± 42
418 ± 37
421 ± 32
<0.001
<0.001
<0.001
0.43
G2
475 ± 49
431 ± 39
433 ± 40
<0.001
<0.001
<0.001
0.71
0.22
0.09
0.12
—
—
—
—
ISV
G1
44.8 ± 26.8
39.2 ± 23.9
39.3 ± 23.8
0.001
0.003
0.003
0.91
G2
43.9 ± 25.8
38.9 ± 22.1
38.8 ± 22.3
0.001
0.004
0.004
0.65
0.48
0.94
0.76
—
—
—
—
IVA
G1
0.47 ± 0.33
0.44 ± 0.28
0.45 ± 0.29
0.33
0.41
0.45
0.39
G2
0.43 ± 0.30
0.41 ± 0.29
0.42 ± 0.29
0.27
0.38
0.41
0.32
0.55
0.68
0.73
—
—
—
—
IHA
G1
19.8 ± 11.2
18.3 ± 11.8
18.2 ± 12.1
0.77
0.69
0.71
0.59
G2
18.3 ± 10.5
17.6 ± 10.6
17.5 ± 10.3
0.67
0.61
0.64
0.93
0.71
0.61
0.29
—
—
—
—
min
G1
6.9 ± 0.45
7.4 ± 0.49
7.4 ± 0.49
0.021
0.032
0.033
0.83
G2
7.1 ± 0.47
7.5 ± 0.51
7.6 ± 0.52
0.041
0.049
0.050
0.57
0.38
0.77
0.22
—
—
—
—
KI
G1
1.1 ± 0.09
1.07 ± 0.1
1.07 ± 0.1
0.009
0.008
0.008
0.89
G2
1.2 ± 0.1
1.09 ± 0.1
1.09 ± 0.1
0.008
0.006
0.006
0.92
0.99
0.86
0.81
—
—
—
—
: unpaired -test for comparison between the 2 groups. Significant values are bolded. max: maximum keratometry. : corneal asphericity. MCT: minimum corneal thickness. ISV: index of surface variance. IVA: index of vertical asymmetry. IHA: index of height asymmetry. min: minimum radius of curvature. KI: keratoconus index.
