Optic perineuritis as the presenting feature of Crohn disease.

Crohn disease (CD) is primarily considered an inflammatory condition of the small and large intestine although associated extraintestinal inflammation is relatively common. Ocular manifestations are generally localized to the anterior chamber and ocular surface but rarely can involve the posterior pole, orbit, and optic nerve. We report a case of an otherwise healthy 42-year-old man who was diagnosed with CD after presenting with acute vision loss from optic perineuritis.