title: Quantitative and conformational characterization of lysozyme deposited on balafilcon and etafilcon contact lens materials.
abstract: OBJECTIVE
  To determine whether differences in lysozyme deposition and/or activity exist on worn etafilcon and balafilcon contact lenses following care with a polyquaternium-based system (PQ) or a polyhexanide-based system (PHMB).
  
  
  METHODS
  Following acid-based deposit extraction, lysozyme concentration was determined via Western blotting and lysozyme activity was determined by a micrococcyl assay.
  
  
  RESULTS
  Lysozyme deposition on etafilcon lenses was greater following disinfection with the PHMB-based system (1551 +/- 371 micro g/lens vs 935 +/- 271 micro g/lens; p < 0.001). Deposition on balafilcon lenses was not influenced by the care regimen (10 +/- 3.5 micro g/lens vs 10 +/- 5 micro g/lens; p = 0.89). For both materials, the percentage of denatured lysozyme was greater when they were exposed to the PHMB-based system (28 vs 21%; p = 0.05 (etafilcon) and 57 vs 40%; p = 0.04 (balafilcon)).
  
  
  CONCLUSIONS
  The quantity and conformation of lysozyme deposited on hydrogel contact lens materials is significantly influenced by both lens material and care regimen.
authors.affiliation: Centre for Contact Lens Research, School of Optometry, University of Waterloo, Waterloo, Ontario, Canada. msenchyn@sciborg.uwaterloo.ca
authors.forename: Michelle
authors.initials: M
authors.lastname: Senchyna
authors.forename: Lyndon
authors.initials: L
authors.lastname: Jones
authors.forename: Derek
authors.initials: D
authors.lastname: Louie
authors.forename: Chris
authors.initials: C
authors.lastname: May
authors.forename: Iain
authors.initials: I
authors.lastname: Forbes
authors.forename: Mary-Ann
authors.initials: MA
authors.lastname: Glasier
mesh_terms: D000328:Adult; D001645:Biguanides / Q000494:pharmacology; D015153:Blotting, Western; D018639:Contact Lens Solutions / Q000494:pharmacology; D003263:Contact Lenses, Hydrophilic; D004311:Double-Blind Method; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D008689:Methacrylates; D009113:Muramidase / Q000378:metabolism*; D011108:Polymers / Q000494:pharmacology; D011310:Preservatives, Pharmaceutical / Q000494:pharmacology; D011446:Prospective Studies; D011485:Protein Binding; D012826:Silicone Elastomers
chemical_list: D001645:Biguanides; D018639:Contact Lens Solutions; D008689:Methacrylates; D011108:Polymers; D011310:Preservatives, Pharmaceutical; D012826:Silicone Elastomers; C114176:etafilcon; C064420:polyaminopropylbiguanide; C058655:polyquaternium 1; D009113:Muramidase