Pain in anterior ischemic optic neuropathy

Purpose: The diagnoses of both anterior ischemic optic neuropathy (AION) and optic neuritis are clinical ones with significant overlap of symptoms and signs. This study investigates the presence and character of pain at the onset of AION, in order to evaluate this symptom as a differentiating diagnostic feature between optic neuritis and AION. Methods: Forty-one consecutive patients over 45 years of age with a clinical syndrome consistent with AION were questioned about the presence and character of associated pain. Results: Pain was reported by 12% (5 of 41) of the patients with AION. This is contrasted with data compiled on 448 patients enrolled in the optic neuritis treatment trial, of whom 92.2% complained of pain. Conclusion: While there is overlap in the incidence and character of pain in AION and optic neuritis, its presence/absence remains a useful differentiating feature.