title: Ocular and subjective responses to frequent replacement of daily wear soft contact lenses.
abstract: OBJECTIVE
  A significant number of soft contact lens wearers develop complications as a result of lens contamination. We conducted a single-blind 2 year clinical trial to determine if scheduled frequent replacement of lenses decreases complications.
  
  
  METHODS
  One hundred nineteen non-contact lens wearers were fit with soft contact lenses and randomly assigned to 1 or 3 month replacement schedules or a non-replacement (control) group. All subjects were fit with 0.04 mm thick HEMA (water content: 38%) lenses to be worn on a daily wear basis only. A single multipurpose solution was prescribed for cleaning and disinfection.
  
  
  RESULTS
  The 2-year results showed a significantly greater number of subjects in the non-replacement group exhibited microcysts, infiltrates, clinically significant corneal staining, and limbal and bulbar injection. As a result of lens deposition and damage, approximately twice the number of unscheduled lens replacements per subject were necessary in the non-replacement group compared with the 1 and 3 month replacement groups. Overall subject satisfaction with lens wear decreased in the non-replacement group and increased in the 1 and 3 month replacement groups over the 2-year period.
  
  
  CONCLUSIONS
  Frequent replacement of soft lenses for daily wear as compared to non-replacement daily wear: 1) is less likely to cause contact lens induced complications; 2) reduces the number of unscheduled lens replacements; and 3) improves satisfaction with lens wear.
authors.affiliation: Centre for Contact Lens Research, University of Waterloo, Ontario, Canada.
authors.forename: N
authors.initials: N
authors.lastname: Pritchard
authors.forename: D
authors.initials: D
authors.lastname: Fonn
authors.forename: K
authors.initials: K
authors.lastname: Weed
mesh_terms: D000328:Adult; D003263:Contact Lenses, Hydrophilic / Q000009:adverse effects*; D004209:Disposable Equipment; D005128:Eye Diseases / Q000453:epidemiology / Q000209:etiology; D005260:Female; D006801:Humans; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D015994:Incidence; D008297:Male; D017060:Patient Satisfaction; D011092:Polyethylene Glycols; D016037:Single-Blind Method; D013997:Time Factors
chemical_list: D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D011092:Polyethylene Glycols