title: Contamination risk of reusing daily disposable contact lenses.
abstract: OBJECTIVE
  This study investigated contamination of saline and daily disposable contact lens (DDCL) stored overnight after use in the original blister pack and the practices of a group of DDCL users.
  
  
  METHODS
  Twenty DDCL wearers placed their lenses after 1 day's use back into the blister pack saline (BPS) and left them overnight before transferring both lens and BPS to a new CL case. The lens and BPS were cultured the following day, and total number of organisms, Staphylococci, and gram negative organisms enumerated. Each subject submitted five pairs of lenses over a 1 month period.
  
  
  RESULTS
  Ninety-five percent of subjects had at least one pair of contaminated lenses, and the BPS yielded similar results to the contaminated lenses, with staphylococcal contamination being predominant. Three subjects admitted to not washing their hands before handling their lenses and six to habitual reuse of their lenses with storage in the BPS. There was a higher risk of contamination in male subjects.
  
  
  CONCLUSIONS
  Reuse of lenses poses an important risk for DDCL users because they are unlikely to have received proper training in cleaning and disinfection of lenses and do not use a lens case or disinfecting solutions. Overnight storage in BPS results in contaminated lenses which if reused increases the infection risk especially with Staphylococci. It is important that practitioners carefully educate their patients in correct use of DDCL and, as cost of lenses is a major factor in willingness to reuse, ensure that DDCL is the most suitable choice when prescribing.
authors: Department of Health Technology, The Hong Kong Polytechnic University, Kowloon, Hong Kong. htmboost@polyu.edu.hk
authors: Maureen
authors: M
authors: Boost
authors: Kin-Chiu
authors: KC
authors: Poon
authors: Pauline
authors: P
authors: Cho
mesh_terms: D018639:Contact Lens Solutions; D003261:Contact Lenses / Q000382:microbiology*; D004203:Disinfection / Q000379:methods*; D004209:Disposable Equipment; D004866:Equipment Contamination / Q000517:prevention & control*; D017743:Equipment Reuse / Q000592:standards*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D012189:Retrospective Studies; D012307:Risk Factors; D055815:Young Adult
chemical_list: D018639:Contact Lens Solutions