Ocular Paraneoplastic Diseases

Paraneoplastic disorders are defined as syndromes in which the effects in the end organ are not a direct consequence of the mass or of distant metastasis. Instead, autoimmune response to the primary tumor causes end organ disorder and dysfunction. Paraneoplastic illnesses can occur at any time, before, during, or after identification of the primary malignancy, and in rare cases, the primary malignancy may never be discovered. Ocular paraneoplastic diseases have a wide range of clinical manifestations, ranging from color vision deficiencies to complete blindness. Their diagnosis is complicated by toxicity from antineoplastic agents, nutritional deficiencies, and opportunistic infections. Moreover, the characterization of ocular paraneoplastic disorders is made more difficult by their rarity; there is often insufficient epidemiologic data to estimate their incidence or prevalence. Ancillary testing with ERG and commercially or academically available assays for suspected antibodies elicited by the primary tumor have proven useful. Correct and early identification of the occult malignancy through the ocular exam leads to earlier therapeutic interventions and a better prognosis for the patient. Future therapies will focus on the potential benefits of new immunomodulatory medications in treating the paraneoplastic condition and on tumor surveillance through serial antibody evaluations. This chapter summarizes the salient features of most of the frequently encountered ocular paraneoplastic diseases: cancer-associated retinopathy (CAR), melanoma-associated retinopathy (MAR), paraneoplastic vitelliform retinopathy, bilateral diffuse uveal melanocytic proliferation (BDUMP), paraneoplastic optic neuropathy, and opsoclonus manifesting as paraneoplastic ocular disease.