Table 3.

Agreement between paired readings of the central corneal thickness (CCT), and thinnest point in microns with Pentacam and Orbscan

	Grade	Pentacam	Orbscan	r	p-value*	p-value**	95% limit of agreement	CV
		Mean ± SD	Mean ± SD
CCT (micron)	1	496.83 ± 30.39	485.7 ± 41.91	0.915	<0.001	0.005	−25.5 to 47.7	3.09
	2	462.64 ± 39.37	442.25 ± 47.39	0.954	<0.002	0.000	−9.8 to 50.6	3.97
	3	440.58 ± 35.02	418.25 ± 50.97	0.941	<0.003	0.022	−20.0 to 64.6	4.96
Thinnest point (micron)	1	481.14 ± 32.5	481.40 ± 44.11	0.948	<0.001	0.934	−33.3 to 32.8	2.43
	2	440.96 ± 36.94	432.23 ± 48.99	0.952	<0.002	0.019	−26.2 to 43.7	3.17
	3	400.06 ± 36.17	385.50 ± 49.09	0.892	<0.003	0.017	−31.4 to 60.5	4.87

r: correlation coefficient.

*p-value of correlation coefficient.

**p-value of paired t test.

CV: coefficient of variation.

CCT: Central corneal thickness.