What is the role of visual evoked potential (VEP) testing in the workup of optic neuritis and neuropathy?

Updated: Oct 25, 2019
  • Author: Andrew B Evans, MD; Chief Editor: Selim R Benbadis, MD  more...
  • Print


The VEP characteristically shows an increase in P100 latency of the involved side. The use of steroids in this condition has been controversial.

Trauzettel-Klosinski et al observed that oral prednisone initially had a positive effect on VEP latencies in acute optic neuritis. [15] In this study, 48 patients with acute optic neuritis were treated with either oral methylprednisolone (100 mg/day initially with dosage reduction every 3 days; n=15 [treatment group]) or oral thiamine (100 mg/day; n=33 [control group]), 36 of them in a double-blind procedure. Oral methylprednisolone yielded a faster improvement in VEP latency in the initial phase but had no benefit after 12 weeks or 12 months.

Elvin et al used Doppler ultrasonography, MRI, and VEP measurements to study abnormal optic nerve function. [16] VEP assessments were performed in 16 patients. Patients with impairment of visual acuity and a prolonged VEP initially had a more swollen nerve and increased flow resistance in the affected optic nerve. Statistically significant side-to-side differences were found in the optic nerve diameter and in the resistance to flow in the central retinal artery between the affected and unaffected eyes.

Atilla et al found that VEP amplitude decrease was more significant in patients with ischemic optic neuropathy, whereas latency prolongation was more significant in those with optic neuritis. [17]

Yukagawa et al found delayed P100 latencies in 7 of 46 eyes in patients with uveitis due to human T-lymphotropic virus type 1 (HTLV-1). [18]

Did this answer your question?
Additional feedback? (Optional)
Thank you for your feedback!