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The following is a summary of “Pathogenic mechanisms of immune checkpoint inhibitor (ICI)-associated retinal and choroidal adverse reactions,” published in the January 2025 issue of Ophthalmology by Haliyur et al. 

Researchers conducted a retrospective study to summarize and categorize mechanisms of immune checkpoint inhibitor (ICI)-mediated retinal and choroidal inflammation and discussed the implications for evaluating and managing the adverse reactions.  

They reviewed literature on immune-mediated retinal and choroidal adverse reactions linked to ICI therapy, synthesizing and categorizing the likely pathogenic mechanisms. Based on these mechanisms a rational approach for evaluating patients with ICI-associated inflammatory disorders of the retina and choroid were proposed,  

The results showed that ICI-induced posterior segment adverse reactions were categorized into 3 main mechanisms of unintended inflammation. Type 1 reactions involved T cell activation causing cross-reactivity (Type 1a) or expansion of eye-specific T cells (Type 1b), leading to inflammation similar to uveitic conditions. Type 2 reactions involved non-specific inflammation exacerbated by ICI use, resulting in retinal vasculitis and potential vision-threatening occlusions. Type 3 reactions were characterized by autoantibody-mediated inflammation or paraneoplastic processes, likely driven by T cell-induced B cell expansion.  

Investigators concluded that, although rare, posterior segment inflammatory disorders from ICI therapy can threaten vision if not promptly addressed, with treatment generally offering a favorable prognosis, though some reactions might lead to permanent visual defects. 

Source: ajo.com/article/S0002-9394(25)00006-6/abstract