Methods to Assess Ocular Motor Dysfunction in Multiple Sclerosis

Background: Multiple sclerosis (MS) is an inflammatory disease of the central nervous system causing the immune-mediated demyelination of the brain, optic nerve, and spinal cord and resulting in ultimate axonal loss and permanent neurological disability. Ocular motor dysfunction is commonly observed in MS but can be frequently overlooked or under-appreciated by nonspecialists. Therefore, detailed and quantitative assessment of eye movement function has significant potential for optimization of patient care, especially for clinicians interested in treating visual symptoms or tracking disease progression. Methods: A brief history of eye tracking technology followed by a contextualized review of the methods that can be used to assess ocular motor dysfunction in MS-including a discussion of each method's strengths and limitations. We discuss the rationale for interest in this area and describe new tools capable of tracking eye movements as a possible means of monitoring disease. Results/Conclusions: This overview should inform clinicians working with patients with MS of how ocular motor deficits can best be assessed and monitored in this population. It also provides a rationale for interest in this field with insights regarding which techniques should be used for studying which classes of eye movements and related dysfunction in the disease.