title: Pseudomonas aeruginosa infectious keratitis in a high oxygen transmissible rigid contact lens rabbit model.
abstract: OBJECTIVE
  To establish a rabbit model of infectious Pseudomonas aeruginosa keratitis using ultrahigh oxygen transmissible rigid lenses and characterize the frequency and severity of infection when compared to a non-oxygen transmissible lens material.
  
  
  METHODS
  Rabbits were fit with rigid lenses composed of ultrahigh and non-oxygen transmissible materials. Prior to wear, lenses were inoculated with an invasive corneal isolate of P. aeruginosa stably conjugated to green fluorescent protein (GFP). Corneas were examined before and after lens wear using a modified Heidelberg Rostock Tomograph in vivo confocal microscope. Viable bacteria adherent to unworn and worn lenses were assessed by standard plate counts. The presence of P. aeruginosa-GFP and myeloperoxidase-labeled neutrophils in infected corneal tissue was evaluated using laser scanning confocal microscopy.
  
  
  RESULTS
  The frequency and severity of infectious keratitis was significantly greater with inoculated ultrahigh oxygen transmissible lenses. Infection severity was associated with increasing neutrophil infiltration and in severe cases, corneal melting. In vivo confocal microscopic analysis of control corneas following lens wear confirmed that hypoxic lens wear was associated with mechanical surface damage, whereas no ocular surface damage was evident in the high-oxygen lens group.
  
  
  CONCLUSIONS
  These data indicate that in the absence of adequate tear clearance, the presence of P. aeruginosa trapped under the lens overrides the protective effects of oxygen on surface epithelial cells. These findings also suggest that alternative pathophysiological mechanisms exist whereby changes under the lens in the absence of frank hypoxic damage result in P. aeruginosa infection in the otherwise healthy corneal epithelium.
authors.affiliation: Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, Texas, United States.
authors.forename: Cynthia
authors.initials: C
authors.lastname: Wei
authors.affiliation: Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, Texas, United States.
authors.forename: Meifang
authors.initials: M
authors.lastname: Zhu
authors.affiliation: Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, Texas, United States.
authors.forename: W Matthew
authors.initials: WM
authors.lastname: Petroll
authors.affiliation: Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, Texas, United States.
authors.forename: Danielle M
authors.initials: DM
authors.lastname: Robertson
mesh_terms: D000818:Animals; D015169:Colony Count, Microbial; D003261:Contact Lenses / Q000382:microbiology*; D003315:Cornea / Q000382:microbiology*; D004195:Disease Models, Animal; D015818:Eye Infections, Bacterial / Q000382:microbiology*; D005260:Female; D007634:Keratitis / Q000382:microbiology*; D011552:Pseudomonas Infections / Q000382:microbiology*; D011550:Pseudomonas aeruginosa; D011817:Rabbits; D012720:Severity of Illness Index
keywords: Pseudomonas aeruginosa; contact lens; cornea; epithelium; hypoxia