Background: Multiple sclerosis (MS) is a disease of the central nervous system (CNS) that leads to axonal dysfunction and neuronal loss and often presents optic neuritis (ON). Decreased thickness of the retinal nerve fiber layer (RNFL) is a classic finding on ophthalmoscopic examination of patients with MS and especially noted in those patients with a history of ON. The thickness of the RNFL can be measured by a non-invasive technique, optical coherence tomography (OCT).

Methods: This review will cover the history and development of the OCT technology and the advantages of a potential clinical application as a biomarker for axonal loss in MS.

Conclusions: The use of OCT to quantify axonal loss in the RNFL is a promising tool to evaluate disease progression in MS and ON patients. OCT measurements may also correlate with MRI measured brain atrophy and could provide an easily quantified and highly reproducible method in clinical trials to monitor the efficacy of both immune- and neuroprotective therapies. Potential correlations between OCT with other biomarkers that include low contrast vision, visual evoked potentials, color vision and diffusion tensor imaging of the brain and advanced imaging of the optic nerve are promising new frontiers of research.