Axonal Loss in Non-Optic Neuritis Eyes of Patients With Multiple Sclerosis Linked to Delayed Visual Evoked Potential

Neurology. 2013 Jan 15;80(3):242-5. doi: 10.1212/WNL.0b013e31827deb39. Epub 2012 Dec 26.

Abstract

Objective: Recent studies demonstrate significant thinning of the retinal nerve fiber layer (RNFL) in multiple sclerosis (MS) non-optic neuritis (MS-NON) eyes. However, the pathologic basis of this reduction is not clear. The aim of the current study was to investigate the relationship of the RNFL thickness in MS-NON eyes with latency delay of the multifocal visual evoked potential (mfVEP), a surrogate marker of the visual pathway demyelination.

Methods: Total and temporal RNFL thickness and latency of the mfVEP in 45 MS-NON eyes of 45 patients with relapsing-remitting MS and 25 eyes of age- and gender-matched controls were measured and analyzed.

Results: There was significant reduction of total and temporal RNFL thickness (p = 0.015 and p = 0.006, respectively) and significant latency delay (p < 0.0001) in MS-NON eyes. Both total and temporal RNFL thickness were associated with latency of the mfVEP (r2 = 0.43, p < 0.0001 and r2 = 0.36, p = 0.001, respectively). MS-NON eyes with normal latency (n = 26) showed no significant reduction of RNFL thickness compared with controls (p = 0.44 and p = 0.1 for total and temporal RNFL, respectively), whereas eyes with delayed latency (n = 19) demonstrated significantly thinner RNFL (p = 0.001 and p = 0.0005). MS-NON eyes with delayed latency also had significantly thinner RNFL compared with those with normal latencies (p = 0.013 and p = 0.02). In patients with no previous optic neuritis in either eye, delayed latency and reduced RNFL were bilateral whenever present.

Conclusions: The study demonstrated significant association between RNFL loss and a latency delay of the mfVEP in MS-NON eyes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Axons / pathology*
  • Demyelinating Diseases / pathology
  • Evoked Potentials, Visual*
  • Eye / pathology*
  • Eye / physiopathology
  • Female
  • Humans
  • Male
  • Middle Aged
  • Multiple Sclerosis, Chronic Progressive / pathology*
  • Multiple Sclerosis, Chronic Progressive / physiopathology*
  • Neuritis / pathology*
  • Neuritis / physiopathology
  • Retinal Ganglion Cells / pathology
  • Retinal Neurons / pathology
  • Tomography, Optical Coherence
  • Visual Pathways / pathology