Optic neuritis after anthrax vaccination

Objective: To report the occurrence of optic neuritis after anthrax vaccination in two patients. Design: Observational case reports, review of literature. Methods: Description of clinical history, examination, neuroimaging, and further studies in two patients experiencing optic neuritis in temporal association with anthrax vaccination. Main Outcome Measures: Visual acuity, visual fields. Results: Two patients, 39 and 23 years of age, were seen with acute optic neuritis 1 month and 2 weeks, respectively, after anthrax booster vaccination and successfully treated with intravenous methylprednisolone. The first patient had a typical presentation and course of unilateral retrobulbar optic neuritis with excellent visual recovery. The second patient had a bilateral anterior optic neuritis and has required chronic immunosuppression to maintain his vision. Retinal and optic nerve autoantibodies were present in the second patient. No cross-reactive epitopes between anthrax vaccine and retina/optic nerve were identified. Conclusion: Optic neuritis is a potential adverse reaction of anthrax vaccination.