Primary melanocytic lesions of the rabbit choroid following topical application of 7, 12-dimethmbenz[a] anthracene: Preliminary observations

There are no available animal models of primary human uveal melanoma, a potentially blinding and lethal condition. In an attempt to develop such a model, 7,12-dimethylbenz[a]anthracene in acetone was applied topically to the sclera of Dutch (pigmented) rabbits. Melanocytic hyperplasia was identified histologically in the choroid of 9 of 18 rabbits within 19 weeks following 5-14 weekly topical applications of a 1% solution of 7,12-dimethylbenz[a]anthracene in acetone (10 μ1 per application). The clinical emergence of fundus pigmentation was documented photographically in six of these nine rabbit eyes. This study is, to the best of our knowledge, the first demonstration of a uveal melanocytic response to a chemical carcinogen in an animal eye large enough to be examined clinically.