The Farnsworth-Munsell 100-Hue color vision score and visual evoked potentials in multiple sclerosis

Abstract

In a study of two groups of multiple sclerosis (MS) patients (57 in Vancouver and 78 in Saskatoon) visual evoked potentials (VEP), FM 100-Hue color vision (CV), and automated perimetry were performed. The two groups were similar in age and disease duration but the Saskatoon group were more disabled by their disease. In patients with definite or probable MS with or without a history of optic neuritis (ON) the VEP was more often abnormal than the CV; an abnormality in VEP or CV was found in 95% of Vancouver, and 100% of Saskatoon definite or probable MS patients with a history of ON and in 75% of those with no history of ON. An abnormal red-green color axis was found in only 4% of all definite or probable MS eyes, and an abnormal blue-yellow axis in 6%. Half of the eyes with an abnormal color axis also had an abnormal CV score. In both control eyes and MS eyes the most consistent error scores were located in the 'blue' quadrant of the FM 100-Hue color circle. Of all eyes with an abnormal VEP 42% had an abnormal CV score and of those with an abnormal CV score 58% had an abnormal VEP. Abnormal color vision in MS probably reflects a different pathology than the demyelination responsible for the VEP latency abnormality and the presence of a specific red-green deficiency suggests that the maculo-papillary fibers are not selectively vulnerable.

Key Words:

• Farnsworth-Munsell 100-Hue test
• VEP
• multiple sclerosis
• blue quadrant
• optic neuropathy