The Pathogenesis of Contact Lens-Associated Pseudomonas aeruginosa Corneal Ulceration

A rabbit model of contact-lens associated Pseudomonas aeruginosa corneal ulcer (CLACU) was developed to determine (a) whether lens-associated ulcers could develop in the absence of physical trauma to the corneal epithelium, and (b) whether contact lenses coated with mucin prior to contamination with P. aeruginosa could cause corneal ulcers more readily than uncoated contact lenses. Infections did not occur in nontraumatized corneas, whereas they developed regularly (84%) in corneas with epithelial trauma. In addition, contact lenses that were coated with mucin prior to contamination with P. aeruginosa caused corneal ulcers in a higher proportion of eyes than did noncoated lenses, and the ulcers were more severe in eyes wearing coated lenses. These findings suggest that CLACUs do not occur in the absence of epithelial trauma and that mucin or mucoproteinaceous coatings on contact lenses, by allowing greater adherence of bacteria, predispose to corneal infection. Cleaning of contact lenses with mucolytic and proteolytic enzymes may therefore help reduce the incidence of CLACU.