Paraneoplastic retinopathy: a novel autoantibody reaction associated with small-cell lung carcinoma

We present the case of a 74-year-old man with rapidly progressive bilateral visual loss, optic disc pallor, retinal arteriolar attenuation, and an abnormal electroretinogram with a 90% reduction in cone function and a 50% reduction in rod function. He was examined for a suspected cancer-associated retinopathy (CAR). Although he was found not to have expressed the previously reported 23-kd CAR antibody, high titers were found of an antibody to a 60-kd retinal protein, which as yet remains unidentified. An initial clinical search for an underlying cancer was unsuccessful, but 2 months later a mediastinal mass was found on chest x-rays, and biopsy confirmed a diagnosis of small-cell lung carcinoma. Combined therapy with oral corticosteroids and plasmapheresis resulted in a recovery of vision from counting fingers to 20/200 in the right eye and 20/40 to 20/25 in the left eye. Conventional chemotherapeutic management of the small-cell lung carcinoma was instituted, and the modest visual recovery was maintained. The visual improvement as well as lung tumor regression were accompanied by a decline in antibody titers from 1:2,000 pretreatment to 1:200 during the course of therapy. The absence of reactivity with the previously described 23-kd retinal antigen of the CAR syndrome does not exclude the diagnosis of paraneoplastic retinopathy in patients fitting the clinical profile of this disease.