Table 3.

Descriptive statistics and repeatability of inter-day Pentacam measurements in subjects with keratoconus and healthy controls (mean of replicates).

	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)
Inter-day measurements
Keratoconus patients (n = 25)
A (mm)
All	7.17 (0.48)	(6.34–7.95)	0.046 (0.033–0.059)	0.13 (0.092–0.16)	0.99 (0.98–1.00)		0.64	− 0.377	0.009	− 0.481	0.007
< 7.33	6.81 (0.36)	(6.34–7.33)	0.060 (0.037–0.082)	0.17 (0.10–0.23)	0.97 (0.92–0.99)
≥ 7.33	7.57 (0.20)	(7.34–7.95)	0.024 (0.015–0.034)	0.07 (0.040–0.094)	0.98 (0.95–1.00)
B (mm)	5.52 (0.51)	(4.63–6.44)	0.044 (0.032–0.056)	0.12 (0.088–0.16)	0.99 (0.98–1.00)		0.79	0.113	0.427	0.132	0.265
C (μm)
All	492.7 (35.1)	(442.3–560.8)	2.95 (2.13–3.77)	8.17 (5.91–10.4)	0.99 (0.98–1.00)		0.60	− 0.350	0.016	− 0.480	0.008
< 482.5	463.9 (12.9)	(442.3–482.4)	3.67 (2.20–5.13)	10.2 (6.10–14.2)	0.92 (0.76–0.98)
≥ 482.5	519.3 (26.8)	(482.5–560.8)	2.07 (1.28–2.87)	5.75 (3.54–7.96)	0.99 (0.98–1.00)
Healthy controls (n = 25)
A (mm)	7.77 (0.23)	(7.34–8.21)	0.012 (0.009–0.015)	0.033 (0.024–0.042)	1.00 (0.99–1.00)		0.15	− 0.069	0.638	− 0.104	0.311
B (mm)	6.31 (0.20)	(5.83–6.65)	0.020 (0.015–0.026)	0.056 (0.041–0.072)	0.99 (0.98–1.00)		0.32	0.189	0.190	0.260	0.105
C (μm)	538.8 (23.4)	(497.0–582.6)	2.34 (1.69–2.98)	6.47 (4.68–8.27)	0.99 (0.98–1.00)		0.43	0.171	0.240	0.209	0.158

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.