Studying optic nerve head component abnormalities may help treat MS

The results of this pilot study suggest that studying the relationship between optic nerve head component (ONHC) abnormalities and alterations in validated structural and functional measures of the visual system may facilitate the ability to dissect and characterize the pathobiological mechanisms that contribute to tissue damage in multiple sclerosis (MS). This also may be useful for detecting and monitoring neuroprotective or restorative effects of novel therapies.

The authors used multifocal electroretinography (mfERG)-induced ONHC responses to characterize abnormalities in ONHC responses in eyes of patients with MS. These responses are believed to be contingent upon the transformation in electrical transmission properties of retinal ganglion cell axons from membrane to saltatory conduction mechanisms as they traverse the lamina cribrosa and obtain oligodendrocyte myelin. Subjects in the study were seven patients with MS and 10 normal subjects.

The authors found that the number of abnormal or absent ONHC responses was significantly higher in the eyes of MS patients than the eyes of normal subjects (P < 0.001).

They say these findings are in keeping with a cardinal pathophysiologic principle in MS-associated optic neuropathy: translaminar demyelination (either secondary to acute optic neuritis or as a derivative of occult optic neuropathy) and the loss of the normal transformation of membrane to salutatory electrical transmission properties of retinal ganglion cell axons as they traverse the lamina cribrosa.