Table 1.

Comparison of the corneal power and WTW distance values measured by the 2 devices

Parameters	Orbscan II	iTrace	P valuea
Kf (D)	42.56 ± 1.34	42.06 ± 1.34	<0.0001
Ks (D)	43.76 ± 1.58	43.21 ± 1.57	<0.0001
WTW (mm)	11.57 ± 0.34	11.33 ± 0.36	<0.0001

Data are expressed as mean ± SD; ^apaired t test <0.05 considered significant; Kf = flat axis power; Ks = steep axis power, D = diopter