Objective: To determine whether characteristics of optic nerve swelling assist in distinguishing between optic neuritis and anterior ischemic optic neuropathy.
Method: Optic nerve stereophotograph review by masked observers.
Results: Altitudinal swelling, pallor, arterial attenuation, and hemorrhage are found more commonly in anterior ischemic optic neuropathy than in optic neuritis.
Conclusion: Optic disc appearance does help to distinguish anterior ischemic optic neuropathy from optic neuritis, although there are overlapping features.