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

Objectives: To investigate the clinical and image characteristics of primary systemic vasculitis-associated optic neuritis patients. Methods: This is a retrospective study. The patients clinically diagnosed with primary system vasculitis-induced optic neuritis were recruited from March 2013 to December 2023. All cases received orbital magnetic resonance imaging scans were analyzed. The ocular findings, systemic manifestations, laboratory data and prognosis were reviewed retrospectively. In addition, the related literature was reviewed. Results: Fourteen patients (21 eyes), including 10 men and 4 women, were enrolled in this study. The ages ranged from 30 to 86 years in this cohort. Orbits MRI detects the enlargement and/or enhancement of the optic nerve. Cases 1–5 reported a confirmed diagnosis of Takayasu’s arteritis, and cases 6–8 had giant cell arteritis. Cases 9–13 were antineutrophil cytoplasmic antibody-associated vasculitis. Case 14 was Cogan’s syndrome. Mult organs and tissues, such as the kidneys, heart, paranasal sinuses, meninges, and respiratory system, were involved. In all of the 14 involved patients, the disease onset was either during the fall or winter season. There were no or only slight improvements in visual activity after conventional therapies. Conclusions: The autoantibodies’ attack on the optic nerve, ischemic damage, or destruction of the blood–brain barrier may be the potential pathogenesis of vasculitis-associated optic neuritis. Even with prompt and aggressive clinical interventions, the prognosis remains unsatisfactory.