Table 1.

Mean absolute error in predicted residual astigmatism for each calculator

Calculator	Mean ± SD (range) Diopters	95% CI for mean	p-value
Standard toric calculator based on anterior keratometry values	0.77±0.40 (0.01, 1.91)	0.65–0.86	-
PhysIOL toric calculator with Abulafia-Koch formula	0.35±0.29 (0.00, 1.36)	0.27–0.44	<0.001
Barrett calculator	0.40±0.29 (0.00, 1.07)	0.34–0.51	<0.001
Holladay calculator + Pentacam TCRP	0.72±0.41 (0.02, 1.87)	0.64–0.85	0.656
Holladay calculator + Cassini TCA	0.49±0.30 (0.00, 1.07)	0.37–0.60	0.002

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