Immune checkpoint inhibitors (ICIs) play a significant role in therapy for relapsed or refractory cancers due to their excellent efficacy. ICIs, however, frequently induce immune-related adverse events (irAEs) in various tissues and organs, sometimes leading to severe conditions. Thus, early identification and treatment of irAEs are important. Herein, the authors report two cases of a rare type of irAE, severe keratoconjunctivitis with deterioration of eyesight, induced by ICIs. Characteristically, both cases were accompanied by concurrent severe oral mucositis. The patients were treated successfully with both systemic and topical ophthalmic corticosteroids, resulting in complete remission of severe pseudomembranous conjunctivitis and full recovery of eyesight. ICI-induced keratoconjunctivitis progresses rapidly and can lead to blindness. Thus, prompt diagnosis and treatment are necessary.
Keywords: deterioration of eyesight; immune checkpoint inhibitor; immune-related adverse event; keratoconjunctivitis; pseudomembrane formation.
Lay abstract Currently, ‘immunotherapy’ has changed cancer treatments drastically. In this article, the authors use immune checkpoint inhibitors (ICIs) for cancer treatments as ‘immunotherapy’. Generally, cancer puts on the brakes to stop attacking itself via immune checkpoint molecules to survive. ICIs inhibit the mechanism, and patients battle their cancer by using their own activated lymphocytes. However, the activated lymphocytes can attack patients' own normal tissues and organs. ‘Immune-related adverse events’ can occur everywhere in the body. In this article, the authors present an ICI-related severe eye trouble, which is very rare but can put patients at risk of vision loss.