Limbal vascular response prior to corneal vascularization

In spite of claims of a significant latent period of up to 2 days between corneal injury and the beginning of corneal vascularization, there is evidence of a limbal reaction occurring only hours after injury. In this study, the central area of rat corneas was cauterized to give an injury which was remote from the limbal vessels. The resulting changes in vascular permeability were investigated. Significant emigration of neutrophil polymorphonuclear leucocytes began at 36 min and leakage of Trypan blue was discernible at about 1 hr after injury. Eosinophilic leucocytes do not appear to be involved in the response and mast cells, while not showing signs of increased degranulation, may be decreased in number over several days. The significance of these results in relation to the stimulus factors involved in these changes, and the importance of separating inflammatory and proliferative changes, are diseussed.