Case Report: Presumed Iatrogenic Optic Neuropathy Secondary to Nivolumab Therapy for Advanced Melanoma

Introduction Optic neuropathies can have numerous etiologies, including toxic side effects of medications. Several drugs, including anticancer medications, have been reported to cause iatrogenic optic neuropathy, but optic neuropathy secondary to nivolumab therapy is not commonly reported. Recognizing optic neuropathy as a rare side effect of nivolumab is crucial when presented with acute bilateral optic disc edema. This case report highlights optic neuropathy as a rare side effect of nivolumab therapy for treating advanced melanoma. Case Report A 58-year-old woman presented with acute bilateral optic disc edema and was diagnosed with iatrogenic optic neuropathy as a rare side effect of nivolumab. A unique feature in this case was the rapid development of an optic disc hemorrhage within 20 minutes during the initial ocular examination. The diagnosis was ultimately one of exclusion after an extensive workup. Conclusion When determining the underlying cause of acute optic neuropathies, clinicians should consider iatrogenic sources such as rare medication side effects. An efficient diagnosis allows physicians to alter treatment and potentially discontinue the offending medication to prevent permanent ocular damage. With the increasing use of immune checkpoint inhibitors in oncology, heightened awareness of their potential neuro-ophthalmic adverse effects is essential for early detection and intervention. Implementation of baseline and periodic ophthalmic assessments for patients receiving these medications may help identify subtle changes before progression to symptomatic disease.