TABLE 4.

Association of Binocular Summation Score, Disease Status, Age, and Interocular Difference in Multiple Sclerosis Patients for High-Contrast Visual Acuity and Low-Contrast Letter Acuity

Measure, Variable	Coefficient From Linear Regression Modela	P Value
All patients (N = 1331)
Visual acuity (high-contrast)
MS vs control	−0.09	.6
Age, years	−0.01	.66
Low-contrast, 2.5%
MS vs control	0.02	.9
Age, years	−0.07	<.0001a
Low-contrast, 1.25%
MS vs control	0.04	.9
Age, years	−0.09	<.0001a
MS patients only (N = 1007)
Visual acuity (high-contrast)
ON vs no ON	−0.08	.7
Age, years	−0.01	.2
Low-contrast, 2.5%
ON vs no ON	−0.05	.2
Age, years	−0.07	<.0001a
Low-contrast, 1.25%
ON vs no ON	−1.72	<.0001a
Age, years	−0.11	<.0001a
MS patients only (N = 1007)
Visual acuity (high-contrast)
ON vs no ON	0.01	.78
Age, years	−0.01	.29
Interocular difference, letters	−0.20	.32
Low-contrast, 2.5%
ON vs no ON	0.70	.8
Age, years	−0.07	<.0001a
Interocular difference, letters	−0.14	<.0001a
Low-contrast, 1.25%
ON vs no ON	−1.0	.015a
Age, years	−0.12	<.0001a
Interocular difference, letters	−0.25	<.0001a

MS = multiple sclerosis; ON = history of optic neuritis.

^aLinear regression models were used to examine the relation between binocular summation and various patient characteristics.