title: Melimine-Coated Antimicrobial Contact Lenses Reduce Microbial Keratitis in an Animal Model.
abstract: OBJECTIVE
  To determine the ability of antimicrobial peptide melimine-coated contact lenses to reduce the incidence of microbial keratitis (MK) in a rabbit model of contact lens wear.
  
  
  METHODS
  In vitro antimicrobial activity of melimine-coated contact lenses was determined against Pseudomonas aeruginosa by viable count and a radiolabeled assay. The amount of lipopolysaccharide (LPS) associated with bacteria bound to melimine-coated and control lenses was determined. Ocular swabs from rabbit eyes were collected for assessment of ocular microflora. A rabbit model for MK was developed that used overnight wear of contact lenses colonized by P. aeruginosa in the absence of a corneal scratch. During lens wear, detailed ocular examinations were performed, and the incidence of MK was investigated. Bacteria associated with worn lenses and infected corneas were determined by viable plate count.
  
  
  RESULTS
  Inhibition in viable and total P. aeruginosa adhesion by melimine-coated contact lenses was 3.1 log10 and 0.4 log10, respectively. After colonization, the amount of LPS on lenses was approximately the same with or without melimine. Gram-positive bacteria were found in all the ocular swabs followed by fungus (42%). Melimine-coated lens wear was protective and significantly (odds ratio 10.12; P = 0.012) reduced the incidence of P. aeruginosa-driven MK in the rabbit model. The antimicrobial lenses were associated with significantly (P < 0.001) lower ocular scores, indicating improved ocular signs compared with controls.
  
  
  CONCLUSIONS
  This study showed that contaminated contact lenses can produce MK without corneal epithelial defect in an animal model. Melimine-coated contact lenses reduced the incidence of MK associated with P. aeruginosa in vivo. Development of MK requires viable bacteria adherent to contact lenses, and bacterial debris adherent at the lens surface did not cause keratitis.
authors: School of Optometry and Vision Science, University of New South Wales, Sydney, Australia.
authors: Debarun
authors: D
authors: Dutta
authors: School of Optometry and Vision Science, University of New South Wales, Sydney, Australia.
authors: Ajay K
authors: AK
authors: Vijay
authors: School of Chemistry, University of New South Wales, Sydney, Australia.
authors: Naresh
authors: N
authors: Kumar
authors: School of Optometry and Vision Science, University of New South Wales, Sydney, Australia.
authors: Mark D P
authors: MD
authors: Willcox
mesh_terms: D000818:Animals; D000890:Anti-Infective Agents / Q000494:pharmacology; D023181:Antimicrobial Cationic Peptides / Q000494:pharmacology*; D001422:Bacterial Adhesion / Q000187:drug effects; D020099:Coated Materials, Biocompatible; D015169:Colony Count, Microbial; D003261:Contact Lenses; D003315:Cornea / Q000382:microbiology* / Q000473:pathology; D004195:Disease Models, Animal; D015818:Eye Infections, Bacterial / Q000175:diagnosis / Q000382:microbiology / Q000628:therapy*; D005500:Follow-Up Studies; D007634:Keratitis / Q000175:diagnosis / Q000382:microbiology / Q000628:therapy*; D011446:Prospective Studies; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000302:isolation & purification*; D011817:Rabbits
chemical_list: D000890:Anti-Infective Agents; D023181:Antimicrobial Cationic Peptides; D020099:Coated Materials, Biocompatible; C541912:melimine