Contrast Sensitivity versus Visual Evoked Potentials in Multiple Sclerosis.
OBJECTIVE
To compare the Cambridge contrast sensitivity (CS) test and visual evoked potentials (VEP) in detecting visual impairment in a population of visually symptomatic and asymptomatic patients affected by clinically definite multiple sclerosis (MS).


METHODS
Fifty patients (100 eyes) presenting with MS and 25 healthy subjects (50 eyes) with normal corrected visual acuity were included in this study. CS was determined using the Cambridge Low Contrast Grating test and VEP was obtained in all eyes. Findings were evaluated in two age strata of 10-29 and 30-49 years.


RESULTS
Of the 42 eyes in the 10-29 year age group, CS was abnormal in 22 (52%), VEP was also abnormal in 22 (52%), but only 12 eyes (28%) had visual symptoms. Of the 58 eyes in the 30-49 year group, CS was abnormal in 7 (12%), VEP was abnormal in 34 (58%), while only 11 eyes were symptomatic. No single test could detect all of the abnormal eyes.


CONCLUSIONS
The Cambridge Low Contrast Grating test is useful for detection of clinical and subclinical visual dysfunction especially in young patients with multiple sclerosis. Nevertheless, only a combination of CS and VEP tests can detect most cases of visual dysfunction associated with MS.
Department of Optometry, Paramedical Faculty, Mashhad University of Medical Sciences, Mashhad, Iran.
Javad Heravian
JH
Shandiz
Abbas
A
Nourian
Mercedeh Bahr
MB
Hossaini
Hadi Ostadi
HO
Moghaddam
Abbas-Ali
AA
Yekta
Laleh
L
Sharifzadeh
Parviz
P
Marouzi