Immunotherapy-induced retinopathy mimicking cancer associated retinopathy

Purpose: To report a patient who developed a cancer associated retinopathy (CAR) like syndrome in the setting of pembrolizumab and lenvatinib combination therapy for metastatic endometrial carcinoma. Symptoms resolved with normalization of objective functional tests following cessation of medications. Observations: A 52-year-old female with history of endometrial carcinoma, managed with pembrolizumab infusions and daily oral lenvatinib treatment for 18 months, presented to a tertiary eye center with complaints of nyctalopia, photosensitivity and photopsia. Further investigations revealed a reduction in b-wave amplitude on full field ERG (ffERG), a mild color vision deficit, and positive antiretinal antibodies against carbonic anhydrase II, enolase and arrestin. A preliminary diagnosis of CAR was made. One month following diagnosis, the patient discontinued both lenvatinib and pembrolizumab and subsequently reported significant improvement in her eye symptoms and vision. Repeat ffERG had normalized with a robust b-wave, with an improvement noted on repeat color vision testing. A presumed diagnosis of immunotherapy-induced retinopathy was made, with clinical findings mimicking CAR. Conclusions and importance: Pembrolizumab and lenvatinib treatment may be associated with a reversible retinopathy, with presentation very similar to CAR.