Immune checkpoint inhibitor-associated bilateral optic neuritis.

Optic neuritis is a rare immune-related adverse event of immune checkpoint inhibitor use and may result in poor visual outcomes. We describe an elderly woman with metastatic malignant melanoma treated with nivolumab, a programmed cell death protein 1 immune checkpoint inhibitor. After 2 months, she developed bilateral painless loss of vision due to optic neuritis. Although there is limited evidence, expert opinion favours early corticosteroid use and/or plasma exchange, as recommended for neuromyelitis optica spectrum disorders. Optic neuritis is increasingly recognised as an immune-related adverse event, likely to occur more frequently with greater use of immune checkpoint inhibitors. Its early recognition is important as prompt treatment can improve outcomes.