Rare immune adverse event in treatment of non-small-cell lung carcinoma: durvalumab-associated optic neuritis

A 69-year-old man was admitted to a clinical oncology clinic in December 2022 due to a persistent cough unresponsive to antibiotics.Imaging revealed a right hilar mass, and a subsequent biopsy confirmed the diagnosis of non-small cell lung cancer (squamous cell carcinoma), stage cT4N2M0.The patient received definitive chemoradiotherapy consisting of 66 Gy in 33 fractions (Figure 1A), concurrent with two cycles of cisplatin-vinorelbine.After confirming no apparent progression in imaging, the patient was eligible for consolidation immunotherapy with durvalumab, a programmed-death ligand 1 (PD-L1) blocking antibody, starting in April 2023 [1].After five courses of immunotherapy, in June 2023, the patient reported decreased visual acuity (VA) in his left eye that lasted for approximately a month.Comprehensive examination at a regional ophthalmology department included head and orbital computed tomography and magnetic resonance imaging (MRI), cervical Doppler ultrasonography, visual field test and