Table 4.

Corneal biomechanical properties measured by Corvis ST.

Parameters	Stage 1 (n = 42)	Stage 2 (n = 26)	Stage 3 (n = 12)	Unadjusted		Adjusted
				Diff.a (p)	Diff.b (p)	Diff.c (p)	Diff.d (p)
A1-Length, mm	1.79 ± 0.05	1.84 ± 0.05	1.92 ± 0.09	0.06 (<0.001)	0.13 (<0.001)	0.04 (0.07)	0.10 (<0.001)
A1-Time, ms	6.89 ± 0.25	6.83 ± 0.23	6.66 ± 0.39	−0.07 (0.31)	−0.24 (<0.01)	−0.08 (0.24)	−0.24 (<0.01)
A1-Velocity, m/s	0.14 ± 0.01	0.14 ± 0.02	0.16 ± 0.03	0.00 (0.79)	0.01 (0.07)	0.00 (0.88)	0.01 (0.10)
HC-Time, ms	17.28 ± 0.47	17.39 ± 0.49	17.29 ± 0.31	0.10 (0.37)	0.00 (0.99)	0.10 (0.38)	0.00 (0.99)
Peak distance, mm	2.37 ± 0.15	2.37 ± 0.15	2.47 ± 0.12	−0.01 (0.88)	0.09 (0.06)	−0.00 (0.99)	0.09 (0.05)
HC Radius, mm	6.45 ± 0.62	6.46 ± 1.32	6.49 ± 0.76	0.01 (0.96)	0.04 (0.90)	−0.01 (0.95)	0.01 (0.98)
DA, mm	1.18 ± 0.12	1.19 ± 0.1	1.2 ± 0.15	0.01 (0.79)	0.02 (0.68)	0.05 (0.23)	0.07 (0.22)
A2-Length, mm	1.64 ± 0.35	1.86 ± 0.31	2.02 ± 0.28	0.21 (0.01)	0.37 (<0.001)	0.06 (0.59)	0.19 (0.19)
A2-Time, ms	21.87 ± 0.37	21.89 ± 0.33	21.89 ± 0.54	0.01 (0.90)	0.01 (0.93)	−0.02 (0.87)	0.05 (0.68)
A2-Velocity, m/s	−0.41 ± 0.07	−0.38 ± 0.07	−0.38 ± 0.06	0.03 (0.13)	0.03 (0.26)	0.01 (0.74)	0.00 (0.93)

Data shows the mean ± SD. General linear analysis was performed to test differences (Diff.) between three groups. Bivariate analysis:

^a stage 1 vs. stage 2;

^b stage 1 vs. stage 3.

^c Multivariate analysis: stage 1 vs. stage 2;

^d stage 1 vs. stage 3.

A1-length, cord length of applanation 1; A1-time, time from starting until applanation 1; A1-velocity, the speed of applanation 1; HC-time, time from starting until highest concavity; Peak distance, distance of the apexes at highest concavity; HC Radius, central concave curvature at highest concavity; DA, maximum deformity amplitude at the corneal apex; A2-length, cord length of applanation 2; A2-time, time from starting until applanation 2; A2-velocity, the speed of applanation 2.