Author’s Name(s): Kevin Y. Wu, Diana Danielova Gueorguieva (co-first author), Yoel Yakobi (co-first author), Kevin Y. Wu,, Éric Mazerolle

Author’s Disclosure Block: Kevin Y. Wu, none; Diana Danielova Gueorguieva (co-first author), none; Yoel Yakobi (co-first author), Co-first author. none; Kevin Y. Wu, none; Éric Mazerolle, none

Abstract Body
Purpose: This review aims to provide a comprehensive overview of ocular immune-related adverse events (OirAEs) associated with immune checkpoint inhibitors (ICIs), focusing on their clinical manifestations, underlying mechanisms, and current management strategies. As the use of ICIs expands in oncology, understanding these rare but impactful side effects is crucial to optimize patient care without compromising cancer treatment efficacy. Study Design: This is a narrative review that synthesizes current literature on OirAEs associated with ICIs, covering anterior and posterior segment complications, neuro-ophthalmic disorders, and orbital inflammation. The review also addresses the challenges of diagnosing and managing these events, as well as identifying gaps in knowledge that require further investigation. Methods: Relevant studies were identified through a systematic search of peer-reviewed literature, including case reports, case series, and retrospective analyses of patients treated with ICIs. Data on clinical presentations, proposed mechanisms, and treatment approaches were extracted and summarized. Results: OirAEs, though uncommon, can significantly affect visual function and quality of life. Anterior segment complications such as dry eye and uveitis are among the most frequent, while posterior segment disorders like retinopathies and retinal vasculitis are rarer but more severe. Neuro-ophthalmic conditions, including optic neuritis and myasthenia gravis, present additional diagnostic challenges due to overlapping symptoms with central nervous system metastases. Orbital inflammation, particularly thyroid-like orbitopathy and orbital myositis, has been reported in patients receiving anti-CTLA-4 and anti-PD-1/PD-L1 therapies. Corticosteroids remain the mainstay of treatment, with immunomodulatory therapies reserved for more severe cases. In most instances, temporary or permanent discontinuation of ICI therapy is necessary to prevent irreversible ocular damage. Conclusions: OirAEs represent a growing area of concern in cancer immunotherapy. While corticosteroid treatment is effective in many cases, challenges remain in identifying patients at risk, diagnosing conditions early, and balancing the need for continued cancer treatment with the risk of vision loss. Further research is needed to develop predictive biomarkers, refine treatment protocols, and optimize patient outcomes. Increased awareness among oncologists and ophthalmologists is essential to mitigate the impact of these adverse events.