A study has assessed the sensitivity of optic coherence tomography ( OCT ) and visual evoked potentials ( VEPs ) to visual pathway abnormalities in multiple sclerosis.
A total of 40 subjects with multiple sclerosis, 28 with optic neuritis at least 3 months before ( bilateral in 5 ), underwent assessment of visual acuity, Expanded Disability Status Scale ( EDSS ), optic coherence tomography and visual evoked potentials, the latter quantified with a 0-4 conventional score.
Optic coherence tomography and visual evoked potentials were abnormal in 36% and 56% respectively in all eyes ( p=0.11 ), 68% and 86% in eyes with previous optic neuritis ( p=0.12 ), and in 19% versus 40% in eyes without optic neuritis history ( p=0.007 ).
Combining visual evoked potential and optic coherence tomography increased sensitivity to 89% in optic neuritis and 44% in non-optic neuritis eyes.
Considering all eyes, global retinal nerve fibre layer ( RNFL ) thickness and VEP score were significantly correlated between them ( ρ=−0.63, p less than 0.001 ) and with EDSS ( RNFL: ρ=0.40, p less 0.001; VEP score: ρ=0.47, p less than 0.001 ).
Disease duration correlated with VEP score ( ρ=0.25, p=0.025 ) and RNFL thickness ( ρ=−0.71, p less than 0.001 ).
The study has revealed that, in eyes without optic neuritis, visual evoked potentials were more frequently abnormal than optic coherence tomography, while the two techniques showed similar sensitivity in eyes previously affected by optic neuritis.
The correlation of visual evoked potentials and optic coherence tomography measures with disability prompts further exploration of the two techniques as potential markers of disease burden. ( Xagena )
Di Maggio G et al, Mult Scler 2014; Published online before print