Comparison of multifocal visual evoked potential, standard automated perimetry and optical coherence tomography in assessing visual pathway in multiple sclerosis patients.

BACKGROUND

Multifocal visual evoked potentials (mfVEP) measure local response amplitude and latency in the field of vision.

OBJECTIVE

To compare the sensitivity of mfVEP, Humphrey visual field (HVF) and optical coherence tomography (OCT) in detecting visual abnormality in multiple sclerosis (MS) patients.

METHODS

mfVEP, HVF, and OCT (retinal nerve fiber layer [RNFL]) were performed in 47 MS-ON eyes (last optic neuritis [ON] attack >or=6 months prior) and 65 MS-no-ON eyes without ON history. Criteria to define an eye as abnormal were: (1) mfVEP amplitude/latency - either amplitude or latency probability plots meeting cluster criteria with 95% specificity; (2) mfVEP amplitude or latency alone (specificity: 97% and 98%, respectively); and (3) HVF and OCT, mean deviation and RNFL thickness meeting p < 0.05, respectively.

RESULTS

MfVEP (amplitude/latency) identified more abnormality in MS-ON eyes (89%) than HVF (72%), OCT (62%), mfVEP amplitude (66%) or latency (67%) alone. Eighteen percent of MS-no-ON eyes were abnormal for both mfVEP (amplitude/latency) and HVF compared with 8% with OCT. Agreement between tests ranged from 60% to 79%. mfVEP (amplitude/latency) categorized an additional 15% of MS-ON eyes as abnormal compared with HVF and OCT combined.

CONCLUSIONS

mfVEP, which detects both demyelination (increased latency) and neural degeneration (reduced amplitude), revealed more abnormality than HVF or OCT in MS patients.