title: Lens adherence and postlens tear film changes in closed-eye wear of hydrogel lenses.
abstract: BACKGROUND
  Lens adherence and a reduced postlens tear film circulation have been suggested as factors contributing to some adverse reactions in extended wear of hydrogel contact lenses. In this study, we determined lens fitting and postlens tear film characteristics during closed-eye wear.
  
  
  METHODS
  Twenty subjects wore hydrogel lenses for 3 h of eye closure, followed by 30 min of open-eye wear. Lens movement was measured with a video biomicroscope. Postlens tear film appearances in specular reflection were classified as either amorphous, or as one of four color intensity grades, where a colored appearance was taken as indicative of a depleted postlens tear film.
  
  
  RESULTS
  All subjects showed lens adherence (movement < 0.1 mm) and postlens tear film depletion within 45 min of eye closure. These changes were sustained for the remainder of the closed-eye period, but were reversed within 15 min of eye opening. Lens adherence was associated with colored postlens tear film patterns of any intensity.
  
  
  CONCLUSIONS
  Closed-eye wear was invariably associated with the onset of lens adherence and postlens tear film depletion. This finding emphasizes the need for adequate lens movement during the open-eye phase of extended wear.
authors.affiliation: Victorian College of Optometry, Carlton, Victoria, Australia.
authors.forename: A S
authors.initials: AS
authors.lastname: Bruce
authors.forename: J C
authors.initials: JC
authors.lastname: Mainstone
mesh_terms: D000268:Adhesiveness; D000328:Adult; D003262:Contact Lenses, Extended-Wear; D005143:Eyelids / Q000502:physiology*; D005260:Female; D006801:Humans; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D008297:Male; D009038:Motion; D011092:Polyethylene Glycols; D013666:Tears / Q000502:physiology*; D013997:Time Factors
chemical_list: D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D011092:Polyethylene Glycols