Cancer associated retinopathy (CAR): An autoimmune-mediated paraneoplastic syndrome

Cancer associated retinopathy (CAR) is an uncommon paraneoplastic retinopathy in which antibodies are directed against retinal antigens. Vision loss is associated with abnormal ERG findings. Few case reports and lack of controlled clinical trials make management of this syndrome especially challenging for the clinician. Herein, we describe the clinical, histopathologic and electrophysiologic features of CAR, along with a summary of previously employed management options. Cancer associated retinopathy syndrome has been recognized as a paraneoplastic disorder, most commonly associated with small cell lung cancer, in which cross-reacting autoantibodies against retinal antigen cause retinal dysfunction. Bilateral vision loss as a result of both rod and cone dysfunction in CAR may occur over a period of months, and visual symptoms may precede diagnosis of the systemic malignancy. The heterogeneity in antigens that have been identified as targets of antibody-mediated retinal damage perhaps help to explain the complexity of symptoms and the treatment challenges posed by patients with CAR.