title: Optical coherence tomography and visual evoked potentials: which is more sensitive in multiple sclerosis?
abstract: OBJECTIVE
  To assess the sensitivity of optic coherence tomography (OCT) and visual evoked potentials (VEPs) to visual pathway abnormalities in multiple sclerosis (MS).
  
  
  METHODS
  A total of 40 MS subjects, 28 with optic neuritis (ON) at least 3 months before (bilateral in 5), underwent assessment of visual acuity, Expanded Disability Status Scale (EDSS), OCT and VEPs, the latter quantified with a 0-4 conventional score.
  
  
  RESULTS
  OCT and VEPs were abnormal in 36% and 56% respectively in all eyes (p=0.11), 68% and 86% in eyes with previous ON (p=0.12), and in 19% versus 40% in eyes without ON history (p=0.007). Combining VEP and OCT increased sensitivity to 89% in ON and 44% in non-ON eyes. Considering all eyes, global retinal nerve fibre layer (RNFL) thickness and VEP score were significantly correlated between them (ρ=-0.63, p<0.001) and with EDSS (RNFL: ρ=0.40, p<0.001; VEP score: ρ=0.47, p<0.001). Disease duration correlated with VEP score (ρ=0.25, p=0.025) and RNFL thickness (ρ=-0.71, p<0.001).
  
  
  CONCLUSIONS
  In eyes without ON, VEPs were more frequently abnormal than OCT, while the two techniques showed similar sensitivity in eyes previously affected by ON. The correlation of VEPs and OCT measures with disability prompts further exploration of the two techniques as potential markers of disease burden.
authors.affiliation: San Raffaele Scientific Institute, Department of Neurology and Institute of Experimental Neurology-INSPE, Milan, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Di Maggio
authors.affiliation: San Raffaele Scientific Institute, Department of Neurology and Institute of Experimental Neurology-INSPE, Milan, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Santangelo
authors.affiliation: San Raffaele Scientific Institute, Department of Neurology and Institute of Experimental Neurology-INSPE, Milan, Italy.
authors.forename: Simone
authors.initials: S
authors.lastname: Guerrieri
authors.affiliation: San Raffaele Scientific Institute, Department of Neurology and Institute of Experimental Neurology-INSPE, Milan, Italy.
authors.forename: Mariangela
authors.initials: M
authors.lastname: Bianco
authors.affiliation: San Raffaele Scientific Institute, Department of Neurology and Institute of Experimental Neurology-INSPE, Milan, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Ferrari
authors.affiliation: San Raffaele Scientific Institute, Department of Neurology and Institute of Experimental Neurology-INSPE, Milan, Italy.
authors.forename: Stefania
authors.initials: S
authors.lastname: Medaglini
authors.affiliation: San Raffaele Scientific Institute, Department of Neurology and Institute of Experimental Neurology-INSPE, Milan, Italy.
authors.forename: Mariaemma
authors.initials: M
authors.lastname: Rodegher
authors.affiliation: San Raffaele Scientific Institute, Department of Neurology and Institute of Experimental Neurology-INSPE, Milan, Italy.
authors.forename: Bruno
authors.initials: B
authors.lastname: Colombo
authors.affiliation: San Raffaele Scientific Institute, Department of Neurology and Institute of Experimental Neurology-INSPE, Milan, Italy.
authors.forename: Lucia
authors.initials: L
authors.lastname: Moiola
authors.affiliation: San Raffaele Scientific Institute, Department of Neurology and Institute of Experimental Neurology-INSPE, Milan, Italy.
authors.forename: Raffaella
authors.initials: R
authors.lastname: Chieffo
authors.affiliation: San Raffaele Scientific Institute, Department of Neurology and Institute of Experimental Neurology-INSPE, Milan, Italy.
authors.forename: Ubaldo
authors.initials: U
authors.lastname: Del Carro
authors.affiliation: San Raffaele Scientific Institute, Department of Neurology and Institute of Experimental Neurology-INSPE, Milan, Italy.
authors.forename: Vittorio
authors.initials: V
authors.lastname: Martinelli
authors.affiliation: San Raffaele Scientific Institute, Department of Neurology and Institute of Experimental Neurology-INSPE, Milan, Italy.
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Comi
authors.affiliation: San Raffaele Scientific Institute, Department of Neurology and Institute of Experimental Neurology-INSPE, Milan, Italy letizia.leocani@hsr.it.
authors.forename: Letizia
authors.initials: L
authors.lastname: Leocani
mesh_terms: D000328:Adult; D004185:Disability Evaluation; D004569:Electroencephalography; D005074:Evoked Potentials, Visual; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000175:diagnosis* / Q000473:pathology / Q000503:physiopathology; D009900:Optic Nerve / Q000473:pathology* / Q000503:physiopathology*; D009902:Optic Neuritis / Q000175:diagnosis* / Q000473:pathology / Q000503:physiopathology; D010775:Photic Stimulation; D011237:Predictive Value of Tests; D011379:Prognosis; D011930:Reaction Time; D055351:Retinal Neurons / Q000473:pathology*; D012720:Severity of Illness Index; D013997:Time Factors; D041623:Tomography, Optical Coherence; D014792:Visual Acuity
keywords: Multiple sclerosis; disability; optic coherence tomography; optic neuritis; spectral domain; visual evoked potentials