title: Prevention and removal of lipid deposits by lens care solutions and rubbing.
abstract: OBJECTIVE
  Despite the prevalence of silicone hydrogel (SiHy) contact lenses, there are relatively few studies that evaluate the efficacy of multipurpose lens care solutions (MPSs) in reducing lipid deposition on these lenses and the effect of rubbing on the removal. Therefore, we used an in vitro soaking and rubbing model to compare the effectiveness of borate buffered saline (BBS) and two commercial MPSs, PureMoist and Biotrue, in preventing sorption of representative polar and nonpolar lipids.
  
  
  METHODS
  Radiolabeled cholesterol (CH) and dipalmitoylphosphatidylcholine (DPPC) were sorbed on two SiHy lenses (senofilcon A and balafilcon A) from an artificial tear fluid. Deposition and removal were evaluated by quantitative solvent extraction and scintillation counting.
  
  
  RESULTS
  The efficiencies of the MPSs in reducing lipid deposition are somewhat dependent on lens material. Both DPPC and CH sorption on senofilcon A are greater when lenses are preconditioned in BBS compared with preconditioning in either MPS (p < 0.05). However, neither MPS affects lipid sorption on balafilcon A lenses (p > 0.05). As for removal of presorbed lipids, neither PureMoist, Biotrue, nor BBS removed CH in the absence of rubbing. When a simulated rubbing protocol was used, minimal but detectible CH was removed (p < 0.05) from senofilcon A and balafilcon A lenses (likely only from the lens surface). These commercial solutions were not substantially better than BBS in removing DPPC, with or without rubbing (p > 0.05).
  
  
  CONCLUSIONS
  These data suggest that MPSs do not appreciably alter lipid sorption. Rubbing lenses removes a small amount of sorbed lipids. Yet, we recommend that MPSs be used as they may disinfect SiHy lenses and may clean their surfaces of large particles.
authors.affiliation: *MS †PhD ‡BS Brigham Young University, Provo, Utah (NKT, WGP, KXP, JWH, AAG); and Bausch + Lomb, Rochester, New York (JC, XML, EPM).
authors.forename: Ngai Keung
authors.initials: NK
authors.lastname: Tam
authors.forename: William G
authors.initials: WG
authors.lastname: Pitt
authors.forename: Krystian X
authors.initials: KX
authors.lastname: Perez
authors.forename: John W
authors.initials: JW
authors.lastname: Hickey
authors.forename: Andrew A
authors.initials: AA
authors.lastname: Glenn
authors.forename: Joseph
authors.initials: J
authors.lastname: Chinn
authors.forename: X Michael
authors.initials: XM
authors.lastname: Liu
authors.forename: E Peter
authors.initials: EP
authors.lastname: Maziarz
mesh_terms: D015060:1,2-Dipalmitoylphosphatidylcholine / Q000032:analysis*; D002784:Cholesterol / Q000032:analysis*; D018639:Contact Lens Solutions / Q000494:pharmacology*; D003263:Contact Lenses, Hydrophilic; D020100:Hydrogels; D050356:Lipid Metabolism / Q000187:drug effects*; D012828:Silicones
chemical_list: D018639:Contact Lens Solutions; D020100:Hydrogels; D012828:Silicones; C523195:balafilcon A; C523196:senofilcon A; D015060:1,2-Dipalmitoylphosphatidylcholine; D002784:Cholesterol