Visual pathway involvement in multiple sclerosis: Look straight in the eyes.

Visual symptoms are a common clinical manifestation of multiple sclerosis (MS) and are frequently due to acute optic neuritis (ON). However, the entire visual pathway can be involved throughout the disease course. We describe the case of a young MS patient who experienced visual symptoms that were eventually found to be caused by retinal periphlebitis, an inflammatory process of the anterior visual pathway, which is common during MS, but rarely symptomatic. This case reinforces the concept that in all MS patients complaining visual symptoms, a complete work-up should be performed in order to rule out possible ON mimicries.