Table 3.
Area under curve (AUC) of Corneal Visualization Scheimpflug Technology (Corvis ST) parameters with their standard error (SE), 95% confidence interval (CI), and their best cut-offs for optimizing sensitivity and specificity to separate normal and keratoconic corneas.
| Variable | Cut-off point | Sensitivity (%) | Specificity (%) | AUC | SEa | 95% CIb |
|---|---|---|---|---|---|---|
| A1T (ms) | ≤7.03 | 93.75 | 92.00 | 0.955 | 0.0218 | 0.893–0.986 |
| A1L (mm) | ≤1.67 | 50.00 | 94.00 | 0.675 | 0.0594 | 0.573–0.766 |
| A1V (m/s) | >0.12 | 68.75 | 64.00 | 0.692 | 0.0533 | 0.591–0.782 |
| A2T (ms) | >21.4 | 68.75 | 98.00 | 0.898 | 0.0309 | 0.805–0.941 |
| A2V (m/s) | ≤−0.37 | 83.33 | 82.00 | 0.862 | 0.0385 | 0.777–0.923 |
| HCDA (mm) | >1 | 72.9 | 94.00 | 0.893 | 0.0328 | 0.814–0.946 |
| HCR (mm) | ≤6.35 | 77.08 | 100.00 | 0.936 | 0.0242 | 0.868–0.976 |
AUC: Area under curve; SE: Standard error; CI: Confidence interval; A1T: First applanation time; A1L: First applanation length; A1V: First applanation velocity; A2T: Second applanation time; A2V: Second applanation velocity; HCDA: Highest concavity deformation amplitude; HCR: Highest concavity radius.
a
DeLong et al., 1988.
b
Binomial exact.