Intravenous immunoglobulin was effective for recurrent anti-aquaporin 4 antibody-positive optic neuritis

Purpose: To report a case of anti-aquaporin 4 antibody-positive optic neuritis that subsided after intravenous injection of immunoglobulin. Case: A 42-year-old woman presented with blurring of vision in the left eye since 6 days before. Findings: Corrected visual acuity was 1.2 in either eye. Concentric narrowing of visual field was present. The findings were suggestive of retrobulbar optic neuritis in the left eye. Left visual acuity decreased to 0.03 41 days later. Pulsed corticosteroid therapy was ineffective. She proved positive for anti-aquaporin 4 antibody and was diagnosed as optic neuritis related to opticomyelitis. Visual acuity improved to 0.8 after plasma exchange therapy. Recurrence 5 months after initial visit was effectively treated by the same therapy. Recurrence 8 months after initial visit was suppressed after intravenous injection of massive immunoglobulin. She has been doing well for 7 months until present. Conclusion: Intravenous immunoglobulin was effective for recurrent anti-aquaporin 4 antibody-positive optic neuritis.