Current concepts: Contact lens related Pseudomonas keratitis

Despite the development of silicone hydrogel lenses, Pseudomonas aeruginosa (PA) continues to be the leading cause of contact lens related microbial keratitis. Understanding the pathogenesis of PA-mediated corneal infection is critical to the development of new prevention and treatment strategies. Recently intracellular invasion of surface corneal epithelial cells by PA has been revisited as an important element in the infection process. This review identifies the mechanisms involved, and examines the roles of the lens, hypoxia alone, PA stain, cystic fibrosis transmembrane receptor protein (CFTR), and membrane lipid rafts in mediating intracellular invasion in both in vitro and in vivo conditions. Non-toxic blockade of raft formation in vitro or in vivo effectively abrogates PA internalization and may represent a unique, new strategy to prevent or ameliorate lens-related PA microbial keratitis.