Corneal Biomechanical Changes after Crosslinking for Progressive Keratoconus with the Corneal Visualization Scheimpflug Technology
Table 2
CST parameter before and 3months after CXL.
Parameter (unit)
Before CXL
3 months after CXL
Min/Max
Median (Q25/Q75)
Mean (±SD)
Min/Max
Median (Q25/Q75)
Mean (±SD)
IOP (mmHg)
17
7.50/17.00
11.00 (9.00/12.50)
11.26 (2.76)
17
8.00/45.50
14.00 (12.00/16.00)
15.12 (8.31)
0.004†
pachy (µm)
17
415/562
487 (473/539)
498 (42.99)
17
365 /548
452 (438 /502)
463 (45.33)
<0.001
defampmax (mm)
17
0.94/1.41
1.18 (1.08/1.26)
1.16 (0.13)
17
0.44/1.51
1.09 (1.04/1.21)
1.10 (0.22)
0.155†
A1time (ms)
17
6.49/7.50
6.93 (6.78/7.13)
6.96 (0.28)
17
6.61/10.68
7.12 (6.87/7.35)
7.29 (0.92)
0.024†
A1length (mm)
17
1.33/1.89
1.70 (1.53/1.79)
1.65 (0.18)
17
1.22/1.86
1.69 (1.60/1.76)
1.64 (0.18)
0.891
A1velocity (ms)
17
0.09/0.22
0.14 (0.13/0.17)
0.15 (0.04)
17
0.03/0.22
0.15 (0.13/0.17)
0.15 (0.05)
0.902
A2time (ms)
17
21.41/22.86
22.25 (21.84/22.46)
22.16 (0.46)
16
19.07/22.93
21.65 (21.54/21.95)
21.66 (0.83)
0.039†
A2length (mm)
17
0.80/2.41
1.27 (1.09/1.87)
1.43 (0.47)
17
0.78/2.12
1.55 (1.08/1.82)
1.49 (0.44)
0.702
A2velocity (ms)
17
−0.67/−0.26
−0.46 (−0.52/−0.39)
−0.45 (0.11)
16
−0.57/−0.24
−0.44 (−0.49/−0.34)
−0.42 (0.10)
0.348
hctime (ms)
17
16.17/18.25
17.09 (17.09/17.56)
17.27 (0.50)
17
15.25/18.71
17.09 (16.63/17.56)
17.04 (0.77)
0.292
peakdist (mm)
17
2.14/5.62
4.81 (4.68/5.10)
4.46 (1.07)
17
2.01/5.92
4.58 (2.49/5.08)
3.97 (1.36)
0.165
radius (mm)
17
4.27/9.48
5.80 (5.25/6.29)
6.04 (1.27)
17
4.52/9.96
6.04 (5.25/6.56)
6.21 (1.41)
0.488
radius3p (mm)
17
4.27/9.48
5.96 (5.30/6.35)
6.12 (1.28)
17
4.52/9.96
6.04 (5.25/6.56)
6.23 (1.43)
0.683
A1deformationamp (mm)
11
0.09/0.32
0.12 (0.10/0.15)
0.14 (0.06)
8
0.07/0.22
0.13 (0.11/0.18)
0.14 (0.05)
0.544
hcdeformationamp (mm)
11
0.99/1.55
1.14 (1.05/1.33)
1.19 (0.18)
8
0.95/1.41
1.14 (1.07/1.25)
1.16 (0.15)
0.838
A2deformationamp (mm)
11
0.18/0.53
0.38 (0.33/0.42)
0.37 (0.09)
7
0.21/0.44
0.38 (0.28/0.43)
0.36 (0.08)
0.270†
A1deflectionlength (mm)
11
1.85/3.15
2.30 (2.02/2.46)
2.32 (0.36)
7
1.55/2.89
2.33 (2.06/2.79)
2.38 (0.48)
0.612†
hcdeflectionlength (mm)
11
5.50/6.12
5.80 (5.75/6.03)
5.85 (0.19)
8
5.70/6.16
5.90 (5.78/5.96)
5.89 (0.15)
0.699
A2deflectionlength (mm)
10
1.90/3.63
3.00 (2.51/3.09)
2.85 (0.48)
5
2.05/3.50
3.12 (3.04/3.31)
3.00 (0.56)
0.095†
hcdeflectionamp (mm)
11
0.81/1.36
0.97 (0.89/1.09)
1.01 (0.17)
11
0.75/1.36
0.97 (0.91/1.09)
1.00 (0.17)
0.592†
A1deflectionamp (mm)
11
0.07/0.31
0.10 (0.07/0.11)
0.11 (0.07)
11
0.04/0.47
0.10 (0.07/0.18)
0.14 (0.12)
0.188
A2deflectionamp (mm)
11
0.03/0.33
0.13 (0.06/0.19)
0.14 (0.09)
11
0.00/0.69
0.15 (0.09/0.19)
0.20 (0.20)
0.247
deflectionampmax (mm)
11
0.81/1.40
0.98 (0.92/1.09)
1.02 (0.17)
8
0.76/1.26
1.00 (0.93/1.13)
1.02 (0.16)
0.885†
deflectionampmax (ms)
11
15.99/16.83
16.40 (16.17/16.74)
16.44 (0.31)
8
14.35/17.20
15.99 (15.89/16.38)
16.01 (0.81)
0.254
values reaching statistical significance are in bold font. IOP: intraocular pressure; pachy: central corneal pachymetry; defampmax: maximum corneal deformation amplitude; A1time: time of the first applanation; A1length: Length of the first applanation; A1velocity: velocity of the corneal apex at the first applanation; A2time: time of the second applanation; A2length: length of the second applanation; A2velocity: velocity of the corneal apex at the second applanation; hctime: highest concavity, time of the maximum deformation; peakdist: distance between both non-deformed peaks; radius: radius of curvature at maximum deformation, calculated with “parabolic fit”; radius3p: radius of curvature at maximum deformation, 3-point-fit; A1deformationamp: deformation amplitude at the time of the first applanation; hcdeformationamp: deformation amplitude at the time of the highest concavity; A2deformationamp: deformation amplitude at the time of the second applanation; A1deflectionlength: deflection length at the time of the first applanation; hcdeflectionlength: deflection length at the time of the highest concavity; A2deflectionlength: deflection length at the time of the second applanation; hcdeflectionamp: deflection amplitude of the highest concavity; A1deflectionamp: deflection amplitude of the first applanation; A2deflectionamp: deflection amplitude of the second applanation; deflectionampmax (mm): maximum deflection amplitude; deflectionampmax (ms): time of the maximum deflection amplitude.
*Paired -test. †Differences are not normally distributed. Therefore, Wilcoxon matched-pairs test was used.
