Understanding the Different Outcomes of Optic Neuritis

Optic neuritis (inflammation of the optic nerve) is a common side-effect of multiple sclerosis (MS) and leads to many sight-related difficulties, including blurriness, impaired colour recognition and problems with contrast sensitivity. In the majority of these cases, vision spontaneously improves within the first few months. However, in some cases, chronic visual disability is observed following the initial optic neuritis. The reasons behind this are poorly understood.

In this study by Kolbe et al, visual disability and the correlation with white matter injury was studied amongst 23 people, who had both MS and optic neuritis affecting one eye. Results were compared between both the affected and unaffected eye, as well as against 14 neurologically healthy, age and sex matched controls. White matter injury was assessed specifically in the area of the brain associated with the visual pathway, as well as the whole brain.

The results indicated that long-term visual disability after optic neuritis was correlated with white matter injury outside of the visual pathway, most commonly in the frontal lobe. On the other hand, visual problems observed in eyes not affected by optic neuritis were most commonly associated with white matter injury in the visual pathway. It is hoped that a better understanding of the underlying causes of visual disability in people with MS could lead to more accurate prognoses and in the long-term, the development of better treatment options.

This is a summary of “Diffusion Tensor Imaging Correlates of Visual Impairment in Multiple Sclerosis and Chronic Optic Neuritis” by Kolbe et al, published in Investigative Ophthalmology & Visual Science, Feb 2012.