TABLE 3.

Paired Comparisons of Absolute Prediction Errors^a for the Theoretic Prediction Formulae Hoffer Q, Holladay 1, Holladay 2, and Sanders-Retzlaff-Kraff Theoretic for 43 Studied Infant Eyes from the Infant Aphakia Treatment Study

Row Formula and A-Constant Type	Column Formula
	Holladay 1	Holladay 2	SRK/T
Hoffer Q
Manufacturer’s A-constant	1.1 (−0.1, 1.8)b	0.7 (0.1, 1.3)b	1.4 (−0.4, 2.5)b
Adjusted A-constant	1.1 (−0.1, 1.8)b	0.6 (0.1, 1.3)b	1.2 (−0.4, 2.3)b
Holladay 1
Manufacturer’s A-constant		−0.4 (−0.7, 0.3)c	0.3 (−0.3, 0.8)c
Adjusted A-constant		−0.4 (−0.7, 0.3)	0.3 (−0.4, 0.8)
Holladay 2
Manufacturer’s A-constant			1.0 (−0.6, 1.3)d
Adjusted A-constant			0.9 (−0.7, 1.3)c

SRK/T = Sanders-Retzlaff-Kraff theoretic formula.

Data are median (first, third quartiles) of paired differences (in diopters) from: (row formula minus column formula) in absolute prediction error.

^aPredicted refraction minus actual refraction at 1 month. The comparisons of formula absolute prediction errors were performed using paired Wilcoxon signed-rank tests with Bonferroni adjustment. Negative values in the table indicate smaller absolute prediction errors for the row formula; positive values indicate smaller absolute prediction errors for the column formula.

^bP < .005.

^cP < .05.

^dP < .01.