Toxicity of Benzalkonium Chloride on Corneal Endothelium of Rabbits

Park, Seh Kwang; Hahn, Young Ho; Hur, Bang

Abstract

An experimental study was performed on 16 rabbits to evaluate the toxicity of benzalkonium chloride(BAK) on the corneal endothelium. Each rabbit received two drops of 0.01% BAK in the right eye and BSS in the left eye as control. The rabbits were divided into 4 groups: instillation of BAK 20 times at 6-minute intervals in normal cornea(group 1), instillation of BAK 40 times at 3-minute intervals in normal cornea (group 2), instillation of BAK 20 times at 6-minute intervals in de-epithelized condition with the size of 6mm diameter(group 3) and instillation of BAK 40 times at 3-minute intervals in deepithelized cornea(group 4). After the last instillation of BAK, histopathologic examination was performed with electron microscope. Group 1 showed nearly normal corneal endothelial findings, but group 2, 3 and 4 showed enlarged rough endoplasmic reticulum, partially distrupted Goigi apparatus and mitochodria, the presence of vacuoles and phagosomes. Group 4 showed severe destruction of subcellular structures. The results of this study indicate that an exaggerated use of topical drug containing 0.01% BAK may induce corneal endothelial damage, especially when the epithelium was already damaged.