Studies on Vascularization of the Cornea

Abstract

Summary and Conclusions Vascularization of the cornea of rabbits has been studied as a response to bacterial hypersensitiveness. The organisms utilized for inducing hypersensitiveness have been Staphylococcus aureus, Pneumococcus and Bact. granulosis. These bacteria have been administered repeatedly by intracutaneous and sub-conjunctival injections: By conjunctival instillations; a, without corneal scarification; b, with corneal scarification; c, with mixtures of broth cultures and sand; and d, by preliminary instillation of homologous broth filtrates a day preceding the administration of bacteria. Staphylococcus aureus has been the most consistent sensitizing antigen, and instillation with corneal scarification, the most effective method of inducing vascularization of the cornea. Direct corneal vascularization occurs only when the cornea is injured slightly but definitely, but similar trauma per se does not cause this reaction. The corneal vascularity observed during early development resembled pannus tenuis of trachoma, and that observed in the latter stages was suggestive of pannus crassus. It was not possible to correlate corneal sensitivity of the inoculated eye with the presence or absence of corneal sensitivity of the uninoculated eye or to heightened skin reactivity to the homologous bacterial nucleoprotein, or to the presence or absence of circulating antibodies. The antibody response following conjunctival instillations in its various forms was slight or entirely lacking. While the indications are that the vascularity described in this study is in response to bacterial hypersensitiveness, no experiments have been undertaken as yet to indicate whether pannus in trachoma is initiated by a similar stimulus.