Table 1

Characteristics of groups A, A1, and B: A1 and B compared by means of an unpaired Student's t test, Mann–Whitney U test, and the χ² test

Characteristic	Category	Group A (n=119)	Group A1 (n=69)	Group B (n=17)	t /Z /χ²	p Value
Age (months)		mean (SD)	61 (13)	61 (12)	74 (30)	Z −0.92	0.36
Age (months)		median	58	58	57
SER (dioptres)						df 74
		Strabismic	4.0 (2.1)	4.2 (1.9)	3.8 (2.4)	t 0.95	0.35
		Dominant	2.9 (1.8)	2.8 (1.7)	3.1 (2.1)	t 0.73	0.47
		Interoc dif	0.9 (1.5)	1.1 (1.7)	0.5 (0.8)	t −0.57	0.57
Amblyopia category		Strabismic	n=65	n=34	n=12	df 1
Amblyopia category		Mixed	n=54	n=35	n=5	χ² 1.65	0.20
Strabismus category		Esotropia	n=100	n=59	n=15	df 1
Strabismus category		Exotropia	n=19	n=10	n=2	χ²0.001	0.97
BSV		BSV	49 abnormal	37 abnormal	6 abnormal	df 1
		suppression	64 suppression	32 suppression	11 suppression	χ² 0.14	0.52
			6 inconclusive
Fixation		Eccentric	90 eccentric	52 eccentric	11 eccentric	df 1
Fixation		Foveal	29 foveal	17 foveal	6 foveal	χ² 3.62	0.16
First corrected GAC score (log units) mean (SD)						df 74
		Strabismic	0.448 (0.272)	0.431 (0.253)	0.504 (0.249)	t −0.68	0.50
		Dominant	0.903 (0.141)	0.898 (0.118)	0.922 (0.162)	t 0.69	0.49
		Interoc dif	0.456 (0.263)	0.467 (0.241)	0.418 (0.351)	t −1.45	0.15

t = two tail unpaired Student's ttest, applied for interval data which follows a normal distribution.
Z = Mann–Whitney U test, non-parametric version oft test applied to interval data with a non-normal distribution.
χ² = data categorised by dichotomous scale.
df = degrees of freedom.
Interoc dif = interocular difference.
BSV = binocular single vision; SER = spherical equivalent refraction.