Lung cancer-induced blindness.

Early investigations into the pathogenesis of vision loss in cancer patients noted the higher incidence with small cell carcinoma of the lung (SCCL), a neoplasia with suspected neuroendocrine origins [2-5,12,20,25,56,63,64]. The cause and effect relationship between the cancer and retinal deterioration was recognized, but the processes involved were not understood. Research eventually identified a sub-group of paraneoplastic retinopathy patients who exhibited indications of retinal hypersensitivity through their production of autoantibodies reactive with a single photoreceptor protein. The discovery of a small cell lung cancer culture actively expressing this same retinal autoantigen, provided tangible evidence to define a molecular basis for at least one type of paraneoplastic retinopathy. The identification of this immunologic anomaly illustrates how blindness can occur in some cancer patients, through the serendipitous initiation of ocular hypersensitivity, with vision loss developing as a cancer-induced autoimmune retinopathy.