Cancer-Associated Retinopathy (Car) Is Effectively Treated By Ca2+ Antagonist Administration

Cancer-associated retinopathy (CAR) is a paraneoplastic ocular manifestation in which recoverin acts as an autoantigen recognized by sera from patients. Recently, we have found that CAR-like retinal dysfunction was produced by intravitreous administration of antirecoverin antibody in Lewis rat eyes. In the present study, nilvadipine, a Ca2+ antagonist recently found effective as a drug for inherited retinal degeneration, was evaluated for its effectiveness on the retinal degenerations in CAR using these models. Under medication with nilvadipine, the functional and morphological properties of the retinas were evaluated functionally and morphologically following antirecoverin antibody intravitreous injection into Lewis rats' eyes (six rats, 12 eyes in each experimental condition were used). Administration of nilvadipine to the antirecoverin antibody-treated rats caused significant improvement of the deterioration of ERG and normalization of rhodopsin phosphorylation. The present data indicated that antirecoverin antibody-induced retinal dysfunction can be effectively treated by systemic administration of nilvadipine.