Effects of Topically Applied 0.1%Dexamethasone on Endothelial Healing and Aqueous Composition Following Experimental Corneal Alkali Wounds

ABSTRACT

The effects of topical dexamethasone on the endothelial healing and the change of aqueous composition were examined in the repair process of experimental corneal alkali wounds. Corneal alkali wounds were induced, then the eyes were treated topically with either 0.1%dexamethasone or abalanced salt solution[BSS]4 times per day for 8 weeks. Endothelial wound morphometry was performed after alizarin red and trypan blue staining. The concentrations of ascorbic acid, glucose, and the ions, Na, K , Ca2 and Mg2 , were measured in the aqueous humor. Endothelial healing in control corneas showed a biphasic pattern of healingan initial short-term healing for the first week and then a late long-term healing following a secondary endothelial breakdown. Topical administration of 0.1%dexamethasone deterred endothelial healing during the early period and prevented secondary endothelial breakdown. Total repair process of endothelium was accelerated by the dexamethasone treatment. Among the various components of the aqueous humor examined, ascorbic acid seemed most sensitive to change caused by the alkali injury and dexametha-sone treatment. The present data indicate that dexamethasone may have a therapeutic potential in the management of endothelial healing after corneal alkali injury.