Table 2.

Centroid error in predicted residual astigmatism for each calculator

Calculator	Centroid (diopters ± SD @ angle) 95% CI	p-value x component (comparison with standard toric calculator)	p-value y component (comparison with standard toric calculator)
Standard toric calculator based on anterior keratometry values	0.39±0.41 @ 166 0.33–0.45	-	-
PhysIOL toric calculator with Abulafia-Koch formula	0.05±0.34 @ 167 0.00–0.10	<0.001	<0.001
Barrett calculator	0.07±0.28 @ 160 0.03–0.11	<0.001	<0.001
Holladay calculator + Pentacam TCRP	0.23±0.56 @ 158 0.16–0.31	0.134	0.078
Holladay calculator + Cassini TCA	0.10±0.44 @ 156 0.04–0.16	0.009	0.042

Abbreviations: SD, Standard deviation; TCRP, Total Corneal Refractive power; TCA, Total corneal astigmatism.