Bilateral Optic Neuritis in Crohn's Disease

Case Presentation: A 37-year-old black female patient presented with subacute loss of vision in both eyes, which began after the discontinuation of immunosuppressive treatment for Crohn's disease. Seven months after her vision loss, the optical exam revealed counting fingers visual acuity in both eyes and optic disc edema. Orbital MRI showed a longitudinally extensive lesion in the left optic nerve throughout the intraorbital segment of the nerve up to the optic canal. Brain MRI showed only small T2/FLAIR hyperintense lesions ("small patches"). A second follow-up exam, one and a half years after the vision loss, showed finger counting visual acuity in both eyes and optic disc atrophy. A new orbital MRI revealed bilateral optic nerve thinning without new brain abnormalities. Discussion: Crohn's disease is a chronic idiopathic inflammatory disease of the gastrointestinal tract that can present with extraintestinal symptoms, including optic neuritis (ON), which is a rare complication of Crohn's disease. The present case demonstrates that ON can occur following the discontinuation of inflammatory bowel disease treatment, suggesting a reactivation of autoimmune response. Although rare, ON can be bilateral and longitudinally extensive, leading to a poor functional prognosis, with significant impact on the patient's quality of life. Therefore, it is important to closely monitor patients with Crohn's disease, even after treatment discontinuation, to promptly identify and manage potential complications. Final Comments: Optic neuritis is rarely associated with Crohn's disease. This case report demonstrates that optic neuritis can (1) occur after the discontinuation of inflammatory bowel disease treatment, suggesting reactivation of autoimmune response; (2) be bilateral and longitudinally extensive; and (3) have a poor functional prognosis.