. Author manuscript; available in PMC: 2013 Apr 28.

Published in final edited form as: Am J Ophthalmol. 2011 May 12;152(1):133–140. doi: 10.1016/j.ajo.2011.01.023

TABLE 2.

Mean Scores (Numbers of Letters Correct) for High-Contrast Visual Acuity and Low-Contrast Letter Acuity in Patients With Multiple Sclerosis, With or Without a History of Acute Optic Neuritis, and Disease-Free Controls

Visual Function Test	MS (n = 1007)	Disease-Free Controls (n = 324)	MS With No History of ON (n = 544)	MS With History of ON (n = 463)
Visual acuity (high-contrast)
Worse eye score	55 ± 14	61 ±7	57 ± 11	52 ± 17
Better eye score	61 ±9	64 ±6	61 ±8	60 ± 10
Binocular score	62 ±8	66 ±5	63 ±7	61 ± 10
Magnitude of binocular summation^a	1 ±3	1±2	1±3	1± 3
P value^b	<.001	<.001	<.001	<.001
Low-contrast acuity 2.5%
Worse eye score	24 ± 13	34 ±8	27 ± 11	20 ± 14
Better eye score	32 ± 10	37 ±7	33 ±9	30 ± 12
Binocular score	36 ± 10	43 ±6	38 ±9	35 ± 11
Magnitude of binocular summation^a	5 ±4	5±4	5±4	4± 4
P value^b	<.001	<.001	<.001	<.001
Low-contrast acuity 1.25%
Worse eye score	11 ± 11	23 ± 10	14 ± 11	9 ± 10
Better eye score	18 ± 11	27 ±9	19 ± 11	17 ± 11
Binocular score	24 ± 11	34 ±8	26 ± 11	22 ± 12
Magnitude of binocular summation^a	6 ±6	7±5	7±6	5± 6
P value^b	<.001	<.001	<.001	<.001

MS = multiple sclerosis; ON = optic neuritis.

Magnitude of binocular summation calculated as binocular letter score minus monocular letter score for better eye.

P values calculated using a 1-sample t test comparing the mean value to 0 for magnitude of binocular summation.