title: Increase in microbial contamination risk with compression of the lid margin in eyes having cataract surgery.
abstract: OBJECTIVE
  To assess the bacterial contamination risk in cataract surgery associated with mechanical compression of the lid margin immediately after sterilization of the ocular surface.
  
  
  METHODS
  Department of Cataract, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China.
  
  
  METHODS
  Prospective randomized controlled double-masked trial.
  
  
  METHODS
  Patients with age-related cataract were randomly assigned to 1 of 2 groups. In Group A (153 eyes), the lid margin was compressed and scrubbed for 360 degrees 5 times with a dry sterile cotton-tipped applicator immediately after ocular sterilization and before povidone-iodine irrigation of the conjunctival sac. Group B (153 eyes) had identical sterilization but no lid scrubbing. Samples from the lid margin, liquid in the collecting bag, and aqueous humor were collected for bacterial culture. Primary outcome measures included the rate of positive bacterial culture for the above samples. The species of bacteria isolated were recorded.
  
  
  RESULTS
  Group A and Group B each comprised 153 eyes. The positive rate of lid margin cultures was 54.24%. The positive rate of cultures for liquid in the collecting bag was significantly higher in Group A (23.53%) than in Group B (9.80%) (P=.001).The bacterial species cultured from the collecting bag in Group B were the same as those from the lid margin in Group A. The positive culture rate of aqueous humor in both groups was 0%.
  
  
  CONCLUSIONS
  Mechanical compression of the lid margin immediately before and during cataract surgery increased the risk for bacterial contamination of the surgical field, perhaps due to secretions from the lid margin glands.
  
  
  BACKGROUND
  No author has a financial or proprietary interest in any material or method mentioned.
authors.affiliation: From the State Key Laboratory, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China.
authors.forename: Tiantian
authors.initials: T
authors.lastname: Ye
authors.affiliation: From the State Key Laboratory, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China.
authors.forename: Weirong
authors.initials: W
authors.lastname: Chen
authors.affiliation: From the State Key Laboratory, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China.
authors.forename: Nathan
authors.initials: N
authors.lastname: Congdon
authors.affiliation: From the State Key Laboratory, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China. Electronic address: yizhi_liu@yahoo.cn.
authors.forename: Yizhi
authors.initials: Y
authors.lastname: Liu
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001082:Aqueous Humor / Q000382:microbiology; D001419:Bacteria / Q000302:isolation & purification*; D004311:Double-Blind Method; D005143:Eyelids / Q000382:microbiology*; D005260:Female; D006801:Humans; D007431:Intraoperative Complications; D019654:Lens Implantation, Intraocular; D008297:Male; D008405:Massage; D008875:Middle Aged; D018918:Phacoemulsification; D011446:Prospective Studies; D012307:Risk Factors; D013530:Surgical Wound Infection / Q000382:microbiology*; D007507:Therapeutic Irrigation