Human Tear Film Components Bind Pseudomonas Aeruginosa

Abstract

Contact lens-induced Pseudomonas aeruginosa keratitis is one of the leading causes of vision-threatening corneal disease. To cause corneal infection in vivo, P aeruginosa must bind to and colonize the epithelial cell surface. Before interaction can occur with the epithelial cell surface, however, the pathogen must interact with several nonspecific ocular immune components that may help to prevent infection under normal conditions. The tear film contains enzymes such as lysozyme and lactoferrin that provide some amount of antibacterial action. The shearing forces of the blink wipe the ocular surface, enhance the flow of tears across the cornea, and may facilitate removal of pathogens from the eye. Finally, the innermost layer of the human tear film contains mucus, a glycoprotein gel, that improves the spread and stability of aqueous tears, as well as lubricates and protects the underlying corneal epithelium.¹