Demyelinating diseases, such as multiple sclerosis (MS), are frequently associated with the progressive loss of vision. The retinal nerve damage is thought to be caused by immune system-mediated inflammation; however, other demyelinating disorders, such as Pelizaeus-Merzbacher disease, do not involve the immune system, suggesting that there are other causes of retinal nerve damage. Deimination is a protein modification that is altered in patients with MS and PMD.