title: Risk factors for contact lens related microbial keratitis: a case-control study.
abstract: OBJECTIVE
  To evaluate the risk factors that may contribute to microbial keratitis in contact lens wearers.
  
  
  METHODS
  This prospective case-control study included 52 patients with contact lens related keratitis treated between 1 December 2006 and 15 October 2007 at the Faculty of Medicine, Siriraj Hospital. Controls were sixty-three contact lens users attending with disorders unrelated to contact lens wear All subjects with informed consent were interviewed about demographic data, types of contact lens and contact lens solutions, contact lens use past the recommended replacement date, overnight wear, and lens hygiene. Odds ratio (OR, estimates of relative risks) and 95% confidence interval (CI) were calculated through multivariable logistic regression analysis.
  
  
  RESULTS
  The use of contact lens past the replacement date caused the highest risk of developing microbial keratitis (OR = 9.1; CI 1.8-45.4, p = 0.005). Overnight wear of lenses (OR = 2.9, CI 1.3-6.2, p = 0.012) and poor lens hygiene (OR = 2.3, CI 1.0-5.1, p = 0.007) significantly increased the risk of microbial keratitis, respectively. None of the other risk factors showed a significant association.
  
  
  CONCLUSIONS
  The significant risk factors for contact lens related microbial keratitis in the present study were the use of contact lens past the replacement date, overnight wear, and poor lens hygiene. Thus, the appropriate advice of contact lens care and usage may reduce the risk of microbial keratitis in contact lens wearers.
authors.affiliation: Department of Ophthalmology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand. siwbr@mahidol.ac.th
authors.forename: Wipawee
authors.initials: W
authors.lastname: Booranapong
authors.forename: Pinnita
authors.initials: P
authors.lastname: Prabhasawat
authors.forename: Panida
authors.initials: P
authors.lastname: Kosrirukvongs
authors.forename: Yingpan
authors.initials: Y
authors.lastname: Tarawatcharasart
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D018639:Contact Lens Solutions; D003261:Contact Lenses / Q000009:adverse effects*; D005260:Female; D006801:Humans; D006920:Hygiene; D007634:Keratitis / Q000453:epidemiology*; D016015:Logistic Models; D008297:Male; D011446:Prospective Studies; D012307:Risk Factors; D055815:Young Adult
chemical_list: D018639:Contact Lens Solutions