Table 3.

Mean error and mean absolute error form the modified Haigis-L formula in 22 eyes after refractive surgery and refraction prediction within ± 0.50 D, ± 1.00 D, and ± 1.50 D. The predictive accuracy of the modified Haigis-L formula.

	Haigis-L formula	Modified Haigis-L formula	Barret True-K	Shammas-PL
Eyes	22	22	22	22
ME (D) ± SD	−0.18 ± 0.72 (range: −1.34 to 1.93)	0.06 ± 0.59 (range: −0.93 to 1.27)	0.20 ± 0.68 (range: −0.59 to 2.16)	0.15 ± 0.68 (range: −0.66 to 2.30)
Median error (D)	−0.27	0.04	0.13	0.09
MAE (D) ± SD	0.56 ± 0.48 (range: 0 to 1.93)	0.41 ± 0.41 (range: 0 to 1.27)	0.53 ± 0.46 (range: 0 to 2.16)	0.47 ± 0.50 (range: 0 to 2.30)
Median absolute error (D)	0.41	0.19	0.40	0.31
Interquartile range (D)	0.86	0.46	0.92	0.60
Within 0.5 D (%)	54.5	63.6	59.1	63.6
Within 1.0 D (%)	90.9	90.9	90.9	90.9
Within 1.5 D (%)	95.5	100.0	95.5	95.5

D: diopters

ME: mean error

MAE: mean absolute error

SD: standard deviation.