Chronic Relapsing Inflammatory Optic Neuropathy; An Elusive Case

Chronic Relapsing Inflammatory Optic Neuropathy (CRION) is a rare inflammatory demyelinating disease. It is characterized by a steroid suppression dependency and may only be diagnosed after a clinical course of persistent relapses occurring shortly after the discontinuation of corticosteroids with aquaporin-4 antibody negative testing. It occurs less frequently than neuromyelitis optica or multiple sclerosis and is felt to represent a distinct pathologic entity. Usually the visual prognosis with successful recognition and treatment is mostly favorable despite often dramatic vision loss with initial and recurrent presentations; however, it can become permanently sight threatening if unrecognized early.