A Comparative Study of Visual Evoked Potentials in Optic Neuritis and Optic Neuritis with Multiple Sclerosis(cid:31)
Pathanee Samsen MD*, Wanicha L Chuenkongkaew MD*, Patcharapim Masayaanon MD*, Niphon Chirapapaisan MD*, Ngamkae Ruangvaravate MD*, Siriwan Loket BEd*
Affiliation : (cid:31) This article was presented at the 21st congress of the Asia Pacific Academic of Ophthalmology on 10th -14th June 2006 in Singapore * Department of Ophthalmology, Faculty of Medicine, Siriraj Hospital, Mahidol University
Objective : To compare the visual evoked potentials (VEP) in patients with acute optic neuritis, recurrent
optic neuritis, and optic neuritis with multiple sclerosis.
Materials and Methods : The authors retrospectively reviewed VEP latency records of the patients with optic
neuritis in Siriraj Hospital from 1995 to 2005 and divided them into three groups, acute optic neuritis,
recurrent optic neuritis, and optic neuritis with multiple sclerosis (ON/MS). The patients with non-recordable
VEP in the analysis were excluded. Comparison of the mean latency of the VEP in affected eyes among the
three groups was statistically analyzed by a nonparametric independent sample test.
Results : Twenty-two patients with acute optic neuritis, 8 patients with recurrent optic neuritis, and 22 pa-
tients with ON/MS participated in this study. The mean age among the three groups was not statistically
significant. The median value of the latency of flash VEP (fVEP) and pattern reversal VEP (PRVEP) in the
acute optic neuritis group was shorter than that of the recurrent optic neuritis group, and statistically
significant (fVEP, p = 0.012; PRVEP, p = 0.004). The median value of the latency of PRVEP in the acute optic
neuritis group was shorter than that of the ON/MS group, and statistically significant (PRVEP, p = 0.002). The
median value of the latency of both fVEP and PRVEP in the recurrent optic neuritis group and ON/MS group
were delayed with no statistical significance (fVEP, p = 0.458; PRVEP, p = 0.403).
Conclusion : The VEP can be used to demonstrate the demyelinating mechanism of optic neuritis and optic
neuritis with multiple sclerosis, but cannot determine the susceptibility of the patients with acute ON to
become MS. The significantly delayed latency of VEP in recurrent optic neuritis is possibly caused by severe
damage of the optic nerve conduction from recurrent attacks.
Keywords : Acute optic neuritis, Recurrent optic neuritis, Multiple sclerosis, VEP latency
