Delayed onset anterior uveitis and macular edema after cessation of pembrolizumab

Purpose: To report a case of macular edema and anterior uveitis that developed 5 months after discontinuation of pembrolizumab, an immune checkpoint inhibitor. Observations: A 67-year-old man with a history of metastatic clear cell renal cell carcinoma was referred for evaluation of bilateral macular edema and anterior uveitis, potentially attributed to his recently initiated belzutifan and lenvatinib chemotherapy regimen. Upon further review, he had previously been on pembrolizumab and axitinib for 20 months but had stopped five months prior due to cancer progression. Symptoms resolved on difluprednate 0.05% drops, and he restarted his belzutifan and lenvatinib treatment with no recurrence of uveitis. Conclusion and Importance: Ocular immune-related adverse events secondary to immune checkpoint inhibitor therapy can occur months after stopping the medication. It is important for clinicians to recognize the delayed immune-related effects of immune checkpoint inhibitors.