Evaluation of tumor angiogenesis factor with the rabbit cornea model.

Sequential histopathological observations were made of the rabbit corneas after an implantation of viable and nonviable tumor cells in the corneal stroma. They showed a nonspecific localized interstitial keratitis accompanied by inflammatory cells and new capillaries. We could not observe any significant clinical or histopathological differences between the corneas containing live or dead tumor implants, or between those with different tumor types (i.e., retinoblastoma and melanoma). Some variation in the severity of the inflammatory response was observed in different animals with the same tumor. In all cases, the extent of the corneal neovascularization correlated with the degree of inflammation. However, in rabbits made immune-deficient by radiation, there was negligible inflammation and vascularization when tumor was implanted.