This is a 3-year, prospective, multi-center, open-label study to describe the long term changes of optical coherence tomography (OCT) parameters in RRMS patients under treatment with Fingolimod. It is designed to longitudinally study the degeneration of retinal axons by measuring change in RNFL thickness by latest OCT-technology. Correlations of OCT findings with available MRI data and clinical findings may enhance our understanding of the relationship between CNS inflammation, tissue injury, regeneration and neurological deficit in the context of fingolimod therapy.