Table 2.
Descriptive statistics and repeatability of intra-day Pentacam measurements in subjects with keratoconus and healthy controls.
| Mean (SD)a | (Min–Max)a | Sw (95% CI) | RC (95% CI) | ICC (95% CI) | CoV (%) | Kendall’s Tau-bb | pb (2-tailed) | Spearman’s rhob | pb (1-tailed) | ||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Intra-day measurements | |||||||||||
| Keratoconus patients (n = 25) | |||||||||||
| A (mm) | |||||||||||
| Day 0 | 7.18 (0.48) | (6.34–7.99) | 0.054 (0.045–0.063) | 0.15 (0.13–0.17) | 0.99 (0.98–0.99) | 0.78 | − 0.284 | 0.047 | − 0.396 | 0.025 | |
| Day 3 | 7.17 (0.49) | (6.34–7.90) | 0.045 (0.037–0.052) | 0.12 (0.10–0.14) | 0.99 (0.98–1.00) | 0.62 | − 0.264 | 0.065 | − 0.387 | 0.028 | |
| B (mm) | |||||||||||
| Day 0 | 5.53 (0.51) | (4.68–6.45) | 0.049 (0.041–0.056) | 0.13 (0.11–0.16) | 0.99 (0.98–1.00) | 0.88 | − 0.030 | 0.833 | − 0.070 | 0.370 | |
| Day 3 | 5.52 (0.52) | (4.58–6.43) | 0.054 (0.046–0.063) | 0.15 (0.13–0.18) | 0.99 (0.98–0.99) | 0.99 | − 0.193 | 0.176 | − 0.312 | 0.065 | |
| C (μm) | |||||||||||
| Day 0 | 492.6 (35.0) | (442.8–560.3) | 3.85 (3.23–4.46) | 10.7 (8.96–12.4) | 0.99 (0.98–0.99) | 0.78 | − 0.087 | 0.543 | − 0.116 | 0.290 | |
| Day 3 | 492.8 (35.3) | (437.5–561.3) | 3.84 (3.23–4.46) | 10.6 (8.94–12.4) | 0.99 (0.98–0.99) | 0.78 | − 0.044 | 0.761 | − 0.029 | 0.446 | |
| Healthy controls (n = 25) | |||||||||||
| A (mm) | |||||||||||
| Day 0 | 7.77 (0.23) | (7.34–8.20) | 0.012 (0.010–0.013) | 0.032 (0.027–0.037) | 1.00 (1.00–1.00) | 0.15 | 0.024 | 0.864 | 0.18 | 0.466 | |
| Day 3 | 7.77 (0.23) | (7.34–8.23) | 0.013 (0.011–0.015) | 0.035 (0.030–0.041) | 1.00 (0.99–1.00) | 0.16 | − 0.78 | 0.590 | − 0.076 | 0.358 | |
| B (mm) | |||||||||||
| Day 0 | 6.31 (0.19) | (5.83–6.64) | 0.044 (0.037–0.051) | 0.12 (0.10–0.14) | 0.95 (0.91–0.98) | 0.69 | 0.230 | 0.107 | 0.34 | 0.048 | |
| Day 3 | 6.31 (0.20) | (5.83–6.66) | 0.026 (0.022–0.030) | 0.073 (0.061–0.084) | 0.98 (0.97–0.99) | 0.42 | − 0.114 | 0.427 | − 0.141 | 0.251 | |
| C (μm) | |||||||||||
| Day 0 | 538.2 (23.0) | (493.0–580.3) | 3.94 (3.31–4.57) | 10.9 (9.17–12.7) | 0.97 (0.95–0.99) | 0.73 | − 0.179 | 0.215 | − 0.243 | 0.120 | |
| Day 3 | 539.4 (23.8) | (501.0–585.0) | 4.13 (3.46–4.79) | 11.4 (9.60–13.3) | 0.97 (0.95–0.99) | 0.76 | − 0.120 | 0.400 | − 0.212 | 0.154 | |
A = Anterior curvature of the 3 mm zone over the thinnest point (mm). B = Posterior curvature of the 3 mm zone under the thinnest point (mm). C = Thickness of the thinnest point on the cornea (μm).
aSubject mean.
bSubject SD versus subject mean.