Investigation Into the Role of Neuroretinal Biomarkers in the Phenotyping of Neurodegenerative Diseases, and Potential for Tracking Progression and Monitoring Impact of Interventions, Events and Therapies.

The identification of reliable biomarkers in multiple sclerosis (MS), and other neurodegenerative diseases, has become increasingly important with the development of disease-modifying treatments.

A range of genetic, metabolic and imaging biomarkers exist, in correlations with diagnosis, phenotypic expression, inflammation, degeneration and prognosis; although there is wide variation in specificity, sensitivity, reproducibility and cost.

In MS specifically, we know that whilst the primary pathological process is demyelination of neurones (which can be accompanied by inflammation, and resolving symptoms), it is the subsequent axonal loss - neurodegeneration - that gives rise to the permanent functional disability.

Magnetic resonance imaging (MRI) brain scans are currently our primary source of objective information in assessing MS disease status, in terms of neurodegeneration and possibly prognosis. Measurements of brain atrophy have shown worsening rates are higher in untreated MS patients compared with healthy controls and also correlate with subsequent disability status eight years later.

However, brain atrophy measures sometimes reveal paradoxical outcomes, particularly of white matter atrophy, where normal or increased volume as a result of pathological processes, such as tissue damage and repair, can impact upon the measures.