TABLE 3.
Differences of parameters of bilateral corneal biomechanics and the correlation with FKmax of the worse eye.
| Parameters | KC group (n = 173) | Control group (n = 189) | Z a | P a | Correlations with FKmax (worse) | |
|---|---|---|---|---|---|---|
| Mean ± SD (95% CI) | Mean ± SD (95% CI) | r | p | |||
| ΔA1V (m/s) | 0.02 ± 0.02 (0.02, 0.03) | 0.01 ± 0.01 (0.01, 0.01) | −7.218 | <0.001 | 0.413 | <0.001 |
| ΔA2V (m/s) | 0.04 ± 0.03 (0.04, 0.05) | 0.02 ± 0.01 (0.02, 0.02) | −8.112 | <0.001 | 0.436 | <0.001 |
| ΔA1DeflA (mm) | 0.02 ± 0.01 (0.01, 0.02) | 0 ± 0 (0, 0.01) | −9.190 | <0.001 | 0.598 | <0.001 |
| ΔA2DeflA (mm) | 0.02 ± 0.02 (0.02, 0.02) | 0.01 ± 0.01 (0.01, 0.01) | −6.927 | <0.001 | 0.439 | <0.001 |
| ΔDeflA Max (mm) | 0.11 ± 0.09 (0.10, 0.12) | 0.04 ± 0.03 (0.04, 0.05) | −8.882 | <0.001 | 0.474 | <0.001 |
| ΔMax ICR (mm−1) | 0.04 ± 0.04 (0.04, 0.05) | 0.01 ± 0.02 (0.01, 0.02) | −10.045 | <0.001 | 0.438 | <0.001 |
| ΔDAR2 | 1.28 ± 1.1 (1.12, 1.45) | 0.19 ± 0.22 (0.16, 0.22) | −12.784 | <0.001 | 0.606 | <0.001 |
| ΔDAR1 | 0.08 ± 0.07 (0.07, 0.09) | 0.02 ± 0.02 (0.02, 0.03) | −9.700 | <0.001 | 0.316 | <0.001 |
| ΔARTh | 145.93 ± 115.14 (128.65, 163.21) | 51.93 ± 49.21 (44.87, 58.99) | −9.214 | <0.001 | 0.007 | 0.924 |
| ΔMax ICR (mm−1) | 2.69 ± 2.12 (2.37, 3.00) | 0.49 ± 0.35 (0.44, 0.54) | −12.609 | <0.001 | 0.481 | <0.001 |
| ΔSP-A1 (mmHg/mm) | 21.49 ± 14.75 (19.28, 23.71) | 7.36 ± 6.38 (6.44, 8.28) | −10.715 | <0.001 | 0.368 | <0.001 |
| ΔCBI | 0.3 ± 0.4 (0.24, 0.36) | 0.11 ± 0.17 (0.08, 0.13) | −1.037 | 0.300 | −0.230 | 0.002 |
| ΔTBI | 0.16 ± 0.31 (0.11, 0.21) | 0.12 ± 0.11 (0.10, 0.13) | −8.359 | <0.001 | −0.209 | 0.006 |
| ΔSSI | 0.18 ± 0.15 (0.16, 0.20) | 0.07 ± 0.06 (0.06, 0.08) | −8.764 | <0.001 | 0.224 | 0.003 |
| ΔBAD-D | 7.53 ± 5.31 (6.73, 8.32) | 1.21 ± 0.5 (1.14, 1.28) | −15.055 | <0.001 | 0.574 | <0.001 |
Notes: KC, keratoconus; SD, standard deviation; 95% CI, 95% confidence interval for mean; ΔA1V, asymmetry of velocity at the first applanation; ΔA2V, asymmetry of velocity at the second applanation; ΔA1DeflA, asymmetry of the deflection amplitude at the first applanation; ΔA2DeflA, asymmetry of the deflection amplitude at the second applanation; ΔDeflA Max, asymmetry of the maximum deflection amplitude; ΔMax ICR, asymmetry of the maximum inverse concave radius; ΔDAR2, asymmetry of the deformation amplitude ratio at 2mm; ΔDAR1, asymmetry of the deformation amplitude ratio at 1mm; ΔARTh, asymmetry of the Ambrosio Relational Thickness horizontal; ΔIR, asymmetry of the integrated radius; ΔSP-A1, asymmetry of the stiffness parameter at the first applanation; ΔCBI, asymmetry of the Corvis Biomechanical Index; ΔTBI, asymmetry of the Tomographic and Biomechanical Index; ΔSSI, asymmetry of the stress-strain index; ΔBAD-D, asymmetry of the Belin/Ambrosio Enhanced Ectasia Deviation value; mmHg/mm, millimeter of mercury per millimeter; mm, millimeter; ms, millisecond; and m/s, meter per second.
Mann-Whitney U test.