Table 2.

Refractive prediction error, mean absolute error and median absolute error produced by each formula in PEX and control groups without adjusting mean RPE to zero.

	SRK/T	Barrett Universal II	Hill-RBF	P value (Friedman test)
PEX n = 42
RPE ± SD, D (range)	0.321 ± 0.644 (1.440, + 1.710)	0.322 ± 0.641 (− 1.490, + 1.970)	0.283 ± 0.643 (− 1.500, + 1.970)
MAE ± SD, D	0.589 ± 0.406	0.569 ± 0.431,	0.566 ± 0.420
MedAE, D	0.505	0.505	0.410	0.570
Control n = 38
RPE ± SD, D (range)	0.303 ± 0.381 (− 0.480, + 1.355)	0.203 ± 0.371 (− 0.580, + 1.355)	0.188 ± 0.379 (− 0.570, + 1.225)
MAE ± SD, D	0.379 ± 0.303	0.320 ± 0.273	0.312 ± 0.283
MedAE, D	0.333	0.315	0.185	0.001

PEX: pseudoexfoliation syndrome; RPE: refractive prediction error; SD: standard deviation; D: diopter; MAE: mean absolute error; MedAE: median absolute error.