Do visual evoked potentials give relevant information to the neuro-ophthalmological examination in optic nerve lesions?

Abstract

The visual evoked potentials (VEP) and neuro-ophthalmological examinations of 134 patients were compared. The VEP were abnormal in 95% of the eyes with optic neuritis. Defective color vision was found in 99%, visual field defects in 88%, decreased vision in 66% and an afferent pupillary defect in 55%. Patients (29) with optic neuritis were followed up with repeated tests. VEP and color vision recovered more slowly than visual acuity and visual field. Abnormal VEP were observed in 68% of 50 MS [multiple sclerosis] patients. An analysis of symptomatic and asymptomatic eyes showed that testing of color vision, visual field and red-free ophthalmoscopy were equally as useful diagnostic tools as VEP. Of the MS patients 4 (8%) had abnormal VEP despite a normal neuro-ophthalmological examination; 94% of MS patients with symptoms and 47% of MS patients without visual symptoms had abnormal VEP. VEP were pathological in 59% of 24 patients with traumatic or compressive optic nerve diseases or optic atrophies of unknown etiology. The neuro-ophthalmological examination was more sensitive than VEP in the diagnosis of these disorders. A neuro-ophthalmological examination is in most cases sufficient to diagnose optic nerve lesions. VEP are of diagnostic aid especially in mild optic nerve lesions.