Optic neuritis and acute anterior uveitis associated with influenza A infection: a case report

BACKGROUND A few reports have described ocular complications of influenza A infection, such as impaired ocular movement, parasympathetic ocular nerve, keratitis, macular lesion, and frosted branch angiitis. We encountered a rare case of acute anterior uveitis and optic neuritis associated with influenza A infection. CASE PRESENTATION A 70-year-old man presented with symptoms of upper respiratory tract infection. A rapid diagnostic test showed a positive result for influenza A. At the same time, he developed ocular symptoms including blurred vision with optic disk edema and hemorrhage in the left eye, and bilateral red eyes. Multiplex polymerase chain reaction performed on aqueous humor sample detected no viral infection. Visual field testing with a Goldmann perimeter showed central and paracentral scotomas in the left eye. In addition to antiviral agent (oseltamivir phosphate 75 mg), the patient was prescribed topical prednisolone acetate ophthalmic suspension eye drops every 5 hours and high-dose intravenous methylprednisolone 1,000 mg daily for 3 days. Two months later, his best-corrected visual acuity improved to 20/50 with regression of visual field defects in his left eye. CONCLUSION We report a case of bilateral acute anterior uveitis and unilateral optic neuritis concomitant with influenza A infection. Topical and systemic corticosteroids were effective to resolve acute anterior uveitis and neuritis. Analysis of aqueous humor sample suggested that acute anterior uveitis and optic neuritis in this case were not caused by influenza A virus infection per se but by autoimmune mechanism.