title: The efficiency of contact lens care regimens on protein removal from hydrogel and silicone hydrogel lenses.
abstract: OBJECTIVE
  To investigate the efficiency of lysozyme and albumin removal from silicone hydrogel and conventional contact lenses, using a polyhexamethylene biguanide multipurpose solution (MPS) in a soaking or rubbing/soaking application and a hydrogen peroxide system (H(2)O(2)).
  
  
  METHODS
  Etafilcon A, lotrafilcon B and balafilcon A materials were incubated in protein solutions for up to 14 days. Lenses were either placed in radiolabeled protein to quantify the amount deposited or in fluorescent-conjugated protein to identify its location, using confocal laser scanning microscopy (CLSM). Lenses were either rinsed with PBS or soaked overnight in H(2)O(2) or MPS with and without lens rubbing.
  
  
  RESULTS
  After 14 days lysozyme was highest on etafilcon A (2,200 mug) >balafilcon A (50 microg) >lotrafilcon B (9.7 microg) and albumin was highest on balafilcon A (1.9 microg) =lotrafilcon B (1.8 microg) >etafilcon A (0.2 microg). Lysozyme removal was greatest for balafilcon A >etafilcon A >lotrafilcon B, with etafilcon A showing the most change in protein distribution. Albumin removal was highest from etafilcon A >balafilcon A >lotrafilcon B. H(2)O(2) exhibited greater lysozyme removal from etafilcon A compared to both MPS procedures (p<0.001) but performed similarly for lotrafilcon B and balafilcon A lenses (p>0.62). Albumin removal was solely material specific, while all care regimens performed to a similar degree (p>0.69).
  
  
  CONCLUSIONS
  Protein removal efficiency for the regimens evaluated depended on the lens material and protein type. Overall, lens rubbing with MPS before soaking did not reduce the protein content on the lenses compared to nonrubbed lenses (p=0.89).
authors.affiliation: Centre for Contact Lens Research, School of Optometry, University of Waterloo, Waterloo, ON, Canada. dluensma@uwaterloo.ca
authors.forename: Doerte
authors.initials: D
authors.lastname: Luensmann
authors.forename: Miriam
authors.initials: M
authors.lastname: Heynen
authors.forename: Lina
authors.initials: L
authors.lastname: Liu
authors.forename: Heather
authors.initials: H
authors.lastname: Sheardown
authors.forename: Lyndon
authors.initials: L
authors.lastname: Jones
mesh_terms: D000327:Adsorption / Q000187:drug effects; D000818:Animals; D002417:Cattle; D018639:Contact Lens Solutions / Q000494:pharmacology*; D003261:Contact Lenses; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry*; D020100:Hydrogels / Q000737:chemistry; D008689:Methacrylates / Q000737:chemistry; D009113:Muramidase / Q000302:isolation & purification; D011506:Proteins / Q000302:isolation & purification*; D012710:Serum Albumin, Bovine / Q000302:isolation & purification; D012828:Silicones / Q000737:chemistry*
chemical_list: D018639:Contact Lens Solutions; D020100:Hydrogels; D008689:Methacrylates; D011506:Proteins; D012828:Silicones; C523195:balafilcon A; C114176:etafilcon; C524582:lotrafilcon B; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D012710:Serum Albumin, Bovine; C421864:hen egg lysozyme; D009113:Muramidase