title: Microbial contamination of multiply used preservative-free artificial tears packed in reclosable containers.
abstract: OBJECTIVE
  To evaluate microbial contamination of multiply used preservative-free artificial tears packed in reclosable containers after daily use.
  
  
  METHODS
  Subjects were provided with preservative-free artificial tears (Groups 1 and 2) and artificial tears containing a preservative (Group 3). After administration three times or more per 10 h, bottles were collected, and any remaining fluid in the bottles was cultured. A risk factor analysis for microbial contamination was performed by the use of univariate and multivariate analysis.
  
  
  RESULTS
  A total of 242 eye-drop bottles were evaluated. Five (2.0%) of the 242 bottles had bacterial contamination. In group 1, four (3.9%) of 102 bottles were contaminated, and identified bacteria were all coagulase-negative Staphylococcus. In group 2, one (1.0%) of 105 bottles was contaminated, and it was a Gram-negative Acinetobacter species. No bottles from group 3 showed any contamination. Based on multivariate analysis, advanced age and fingertip touch were statistically significant risk factors for microbial contamination (p<0.05).
  
  
  CONCLUSIONS
  Preservative-free artificial tears in reclosable containers are at risk of contamination in a daily and multiple use setting, especially in patients with a poor administering technique, which is associated with fingertip touch and advanced age.
authors.affiliation: Department of Ophthalmology, Sungkyunkwan University School of Medicine, Kangbuk Samsung Hospital, Seoul, Republic of Korea. sashimi0@naver.com
authors.forename: M S
authors.initials: MS
authors.lastname: Kim
authors.forename: C Y
authors.initials: CY
authors.lastname: Choi
authors.forename: J M
authors.initials: JM
authors.lastname: Kim
authors.forename: H R
authors.initials: HR
authors.lastname: Chang
authors.forename: H R
authors.initials: HR
authors.lastname: Chung
authors.forename: H Y
authors.initials: HY
authors.lastname: Woo
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D015169:Colony Count, Microbial; D003315:Cornea / Q000382:microbiology; D004340:Drug Contamination / Q000517:prevention & control; D004349:Drug Packaging / Q000592:standards; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009883:Ophthalmic Solutions / Q000008:administration & dosage; D011310:Preservatives, Pharmaceutical; D013210:Staphylococcus / Q000302:isolation & purification*
chemical_list: D000900:Anti-Bacterial Agents; D009883:Ophthalmic Solutions; D011310:Preservatives, Pharmaceutical