title: Fitting characteristics of Dailies daily disposable hydrogel contact lenses.
abstract: OBJECTIVE
  We evaluated the fitting characteristics of nelfilcon A contact lenses to determine the optimal time for judging lens performance during trial fitting.
  
  
  METHODS
  Twenty subjects wore a pair of DAILIES (daily disposable soft lenses) for 8 hours. A slit lamp camera was used to videotape lens fit every 5 minutes during the first 30 minutes and at 8 hours. Lens movement and centration were measured in 0.1 mm increments by a single observer.
  
  
  RESULTS
  Lens movement decreased significantly during the first 30 minutes of wearing time (P < 0.001). Mean lens movement measured 0.31 mm initially, decreased to 0.17 mm at 25 minutes of wear, and then increased to 0.33 mm at 8 hours (P < 0.001). At 5 minutes, 93% of eyes showed lens movement within 0.2 mm of the value at 8 hours. Lens centration did not change during the first 30 minutes of wear and was comparable to centration measured at 8 hours.
  
  
  CONCLUSIONS
  During trial fitting, the optimal time for evaluating movement of nelfilcon A contact lenses is during the first 5 minutes of wear. Lens movement measured at 8 hours will likely be greater than lens movement measured 10 to 30 minutes after insertion.
authors.affiliation: CIBA Vision Corporation, Duluth, GA 30097, USA.
authors.forename: J D
authors.initials: JD
authors.lastname: Schwallie
authors.forename: R E
authors.initials: RE
authors.lastname: Bauman
mesh_terms: D000328:Adult; D003263:Contact Lenses, Hydrophilic; D004209:Disposable Equipment; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D008297:Male; D008875:Middle Aged; D009038:Motion; D011092:Polyethylene Glycols; D013997:Time Factors
chemical_list: D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D011092:Polyethylene Glycols