title: An evaluation of silicone-hydrogel lenses worn on a daily wear basis.
abstract: OBJECTIVE
  To examine the clinical performance of two brands of silicone-hydrogel lenses when worn on a daily wear basis.
  
  
  METHODS
  Fifty-six subjects with no ocular disease were enrolled at multiple sites in Australasia. Contact lenses made from galyfilcon A or lotrafilcon A were randomly assigned to each eye of the subject and the lenses were worn on a daily wear basis for a period of two weeks. Subjects did not know the identity of the lenses they wore. Clinical data and patient responses to a questionnaire were gathered at an initial visit and after two weeks of wear.
  
  
  RESULTS
  For both lenses, the degree of limbal hyperaemia and bulbar conjunctival hyperaemia decreased significantly over the two-week wearing period. The eyes wearing galyfilcon A lenses showed an increase in conjunctival staining compared to the baseline measures. On average, galyfilcon A lenses decentred more and moved less than the lotrafilcon A lenses. The lotrafilcon A lenses showed a greater loss of wettability, as judged by practitioner grading, than the galyfilcon A lenses over the two-week period. The subjective responses showed strong preference for the galyfilcon A lens across 26 of 27 questions relating to comfort, vision, handling, preference and other subjective outcomes.
  
  
  CONCLUSIONS
  The results show that different silicone-hydrogel lenses have different performance characteristics on the eye, when worn on a daily wear basis. Striving for high oxygen transmissibility at the expense of other properties may lead to a range of undesirable performance characteristics.
authors.affiliation: Brennan Consultants Pty Ltd, Melbourne, Australia. nbrennan@brennanconsultants.com.au
authors.forename: Noel A
authors.initials: NA
authors.lastname: Brennan
authors.forename: M-L Chantal
authors.initials: ML
authors.lastname: Coles
authors.forename: John H-B
authors.initials: JH
authors.lastname: Ang
mesh_terms: D000293:Adolescent; D000328:Adult; D003262:Contact Lenses, Extended-Wear; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D020100:Hydrogels; D008297:Male; D008875:Middle Aged; D017060:Patient Satisfaction; D011446:Prospective Studies; D011474:Prosthesis Design; D017755:Prosthesis Fitting; D012030:Refractive Errors / Q000628:therapy*; D012828:Silicones; D016896:Treatment Outcome; D014785:Vision, Ocular / Q000502:physiology; D005466:Fluorocarbons
chemical_list: D020100:Hydrogels; D012828:Silicones; C481129:lotrafilcon A; D005466:Fluorocarbons