Retinal Neuro-vascular Coupling in Patients With Multiple Sclerosis

Multiple sclerosis (MS) affects approximately 2.3 million patients worldwide, with a global median prevalence of 33 per 100,000. MS is diagnosed at an average of 30 years and affects twice as many women as men. MS is traditionally diagnosed by the presentation of lesions of the central nervous system, disseminated in time and in space, proven by clinical examination and magnetic resonance imaging. Several anatomical parameters in the eye, both vascular and neural, have been found to be altered in MS patients. Because of its unique optical properties, the eye offers the possibility of the non-invasive assessment of both structural and functional alterations in neuronal tissue. As the neuro-retina is part of the brain, it does not come as a surprise that neuro-degenerative changes in the brain are accompanied by structural and possibly also functional changes in the neuro-retina and the ocular vasculature. The current study seeks to test the hypothesis that beside the known anatomical changes, also functional changes can be detected in the retina of patients with MS. For this purpose, flicker light induced hyperemia will be measured in the retina as a functional test to assess the coupling between neural activity and blood flow. Further, structural parameters such as retinal nerve fiber layer thickness and function parameters such as ocular blood flow and retinal oxygenation will be assessed and compared to age and sex matched controls.