Enzyme histochemistry of corneal wound healing.

The usefulness of enzyme histochemical methods for the localization of enzymes as catalysts of molecular interactions in the cells and tissues of healing corneal wounds is shown in rabbits. The current data on corneal wound healing in humans as well as in rabbits with particular reference to serine proteases are reviewed. Some inflammatory mediators are also discussed. Plasmin is a serine protease which is absent (or present only in very low concentration) in the tear fluid, and its activity appears under various pathological conditions in humans or following experimental injuries in rabbits. The role of increasing plasmin activity in the tear fluid in the depending upon the severity of corneal injury is evaluated. Great attention is devoted to conditions leading to long-lasting elevated levels of plasmin activity in the tear fluid correlated with corneal ulceration. The differences between the histochemical pattern of untreated corneas or corneas treated with some serine protease inhibitors are shown, and the efficacy of these drugs is discussed in light of present knowledge.