TABLE 2.

Intraocular Lens Power Calculation Formulae in Infantile Eyes with Unilateral Congenital Cataract: Mean and Median Absolute Prediction Error^a in Diopters, Calculated Using the Formulae Hoffer Q, Holladay 1, Holladay 2, Sanders-Retzlaff-Kraff Theoretic, and Sanders-Retzleff-Kraff II

Group	Absolute Prediction Error (Diopters)
	Hoffer Q	Holladay 1	Holladay 2	SRK/T	SRK II
All eyes (n = 43)
Mean ± SD	2.6 ± 2.0	1.7 ± 1.3	1.9 ± 1.5	1.4 ± 1.1	2.4 ± 1.8
Median	2.1 (0.7, 4.0)	1.2 (0.7, 2.5)	1.4 (0.6, 2.9)	1.3 (0.3, 2.1)	2.2 (0.9, 3.6)
Baseline axial length (mm)
<18.0 (n = 23)
Mean ± SD	3.7 ± 2.0	2.1 ± 1.4	2.5 ± 1.7	1.7 ± 1.3	3.3 ± 1.9
≥18.0 (n = 20)
Mean ± SD	1.3 ± 1.1	1.1 ± 0.8	1.2 ± 0.8	1.1 ± 0.8	1.5 ± 1.1
P value	<.005b	<.01c	<.005b		<.005b
<18.0 (n = 23)
Median	3.8 (2.1, 5.5)	1.7 (0.8, 3.5)	2.2 (1.2, 4.1)	1.6 (0.3, 3.0)	3.3 (2.2, 4.1)
≥18.0 (n = 20)
Median	1.4 (0.4, 1.8)	1.0 (0.6, 1.6)	1.0 (0.5, 1.7)	1.0 (0.4, 1.7)	1.4 (0.4, 2.2)
P value	<.005b	<.05d	<.01c		<.005b

SD = standard deviation; SRK/T = Sanders-Retzlaff-Kraff theoretic; SRK II = Sanders-Retzleff-Kraff II.

Data are mean ± standard deviation and median (first quartile, third quartile) unless otherwise indicated.

^aPredicted refraction minus actual refraction at 1 month. The performance of each formula was compared based on category of baseline globe axial length (<18.0 mm vs ≥18.0 mm). Less error was found using all the formulae for the group of eyes with longer globe axial length, with a significant difference in performance found for each formula except Sanders-Retzlaff-Kraff theoretic formula.

^bP < .005 for a 2-sample t test comparing group means or a Wilcoxon signed-rank test comparing group medians.

^cP < .01 for a 2-sample t test comparing group means or a Wilcoxon signed-rank test comparing group medians.

^dP < .05 for a 2-sample t test comparing group means or a Wilcoxon signed-rank test comparing group medians.