Camrelizumab-Induced Isolate Abducens Neuritis: A Rare Ophthalmic Immune-Related Adverse Events

Anti-tumor immunotherapy with immune checkpoint inhibitors induces several immune-related adverse events. Camrelizumab-related isolate abducens neuritis is rare.

We report on a 67-year-old man with esophageal cancer who presented with acute-onset isolated right abducens cranial nerve palsy after ten cycles of Camrelizumab treatment. Magnetic resonance imaging examination revealed thickening and post-contrast enhancement at the cisternal segment of the right abducens nerve. The diagnosis was immune-related abducens neuritis caused by Camrelizumab. We put him on oral taper corticoids (methylprednisone) for neuritis treatment without Camrelizumab suspension. One month after treatment, he recovered completely. At the last follow-up, one year after the onset of diplopia, the patient was in good condition without neurological symptom recurrence.

Abducens neuritis is a rare immune-related adverse outcome of Camrelizumab. The present case proves the efficacy and safety of using corticoids in the treatment of abducens neuritis.