title: Interactions of lens care with silicone hydrogel lenses and effect on comfort.
abstract: OBJECTIVE
  The purpose of this study was to investigate the effect of lens care products on short-term subjective and physiological performance silicone hydrogel lenses.
  
  
  METHODS
  Ten subjects wore either lotrafilcon B or galyfilcon A silicone hydrogel contact lenses soaked in a lens care product containing either Polyquad/Aldox or PHMB or control lenses inserted directly from the pack. Subjects wore the lenses for 6 h. Ocular comfort (graded on a 1 to 10 scale) and ocular physiology were assessed. Unworn but soaked lenses were analyzed for metrological changes, release of excipients into phosphate buffered saline, and changes to their surface chemical composition.
  
  
  RESULTS
  None of the lens metrology measures or clinically observed conjunctival or limbal redness changed. Corneal staining was significantly (p < 0.008) raised, albeit to low levels, after 6 h wear for either lens type when soaked in the PHMB solution compared with the control lens (lotrafilcon B 0.4 to 0.9 ± 0.7 to 0.4 vs. 0.1 to 0.4 ± 0.3 to 0.5; galyfilcon A 0.2 to 0.3 ± 0.2 to 0.4 vs. 0.0 ± 0.0). For lotrafilcon B lenses, there were decreases in comfort (p = 0.002), increases in burning/stinging (p = 0.002) after 1 h of wear, and increases in lens awareness on lens insertion (p = 0.0001) when soaked in PHMB. However, lotrafilcon B lenses soaked in Polyquad/Aldox showed increases in burning/stinging after 1 and 6 h (p < 0.008) of lens wear. For galyfilcon A lenses, most significant (p ≤ 0.002) changes to symptomatology occurred after soaking in Polyquad/Aldox solution. More PHMB was released from lotrafilcon B lenses, and more MPDS material was released from galyfilcon A lenses. The surface of galyfilcon A lenses changed but irrespective of lens solution type, whereas the changes to the lens surface was dependent on solution type for lotrafilcon B lenses.
  
  
  CONCLUSIONS
  Lens care products can change corneal staining and comfort responses during wear. These changes may be associated with release of material soaked into lenses or changes to the lens surface composition.
authors.affiliation: Brien Holden Vision Institute, The University of New South Wales, Sydney, New South Wales, Australia. m.willcox@ier.org.au
authors.forename: Mark D P
authors.initials: MD
authors.lastname: Willcox
authors.forename: Bronwen
authors.initials: B
authors.lastname: Phillips
authors.forename: Jerome
authors.initials: J
authors.lastname: Ozkan
authors.forename: Isabelle
authors.initials: I
authors.lastname: Jalbert
authors.forename: Laurence
authors.initials: L
authors.lastname: Meagher
authors.forename: Thomas
authors.initials: T
authors.lastname: Gengenbach
authors.forename: Brien
authors.initials: B
authors.lastname: Holden
authors.forename: Eric
authors.initials: E
authors.lastname: Papas
mesh_terms: D000328:Adult; D018639:Contact Lens Solutions / Q000493:pharmacokinetics / Q000494:pharmacology*; D003263:Contact Lenses, Hydrophilic / Q000009:adverse effects; D003315:Cornea / Q000187:drug effects / Q000378:metabolism; D005123:Eye / Q000378:metabolism / Q000473:pathology; D005260:Female; D006801:Humans; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D020100:Hydrogels; D006902:Hydroxymercuribenzoates / Q000494:pharmacology; D008297:Male; D056951:Photoelectron Spectroscopy; D011108:Polymers / Q000493:pharmacokinetics / Q000494:pharmacology; D011437:Propylamines / Q000493:pharmacokinetics / Q000494:pharmacology; D011446:Prospective Studies; D012828:Silicones; D013194:Staining and Labeling; D013499:Surface Properties / Q000187:drug effects; D013997:Time Factors; D014792:Visual Acuity
chemical_list: D018639:Contact Lens Solutions; D020100:Hydrogels; D006902:Hydroxymercuribenzoates; D011108:Polymers; D011437:Propylamines; D012828:Silicones; C540499:galyfilcon A; C524582:lotrafilcon B; C030601:4-hydroxymercuribenzoate; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; C058655:polyquaternium 1; C401661:myristamidopropyl dimethylamine