Extra-Axonal Ocular Damage Quantification by Multifocal Electroretinography in Chronic Progressive Multiple Sclerosis

Immune mechanisms in multiple sclerosis (MS) are more complex than previously thought, are mediated by both T and B cells, and produce demyelination and axonal pathology in both grey and white matter.1 Previous studies have focused on optical coherence tomography (OCT) measurements of retinal nerve fiber layer (RNFL) thinning corresponding to visual deterioration in MS.2 More recent findings, however, indicate retinal pathology involving the inner and outer nuclear layers as well (e.g, bipolar and Muller cells, and photoreceptors).3,4 Because multifocal electroretinogram (mfERG) measures inner and outer retinal layer function, this may be indicated as a useful technique to detect and follow inner and outer retinal dysfunction in MS.