title: Lack of effect of prophylactic gentamicin treatment on intraocular and extraocular fluid cultures after pars plana vitrectomy.
abstract: OBJECTIVE
  To analyze the effect of preoperative prophylatic 0.3% gentamicin sulfate eyedrops on intraocular and extraocular fluid cultures after pars plana vitrectomy.
  
  
  METHODS
  Forty consecutive patients undergoing pars plana vitrectomy were randomly assigned to receive either 0.3% gentamicin eyedrops or placebo preoperatively. Fluids from the vitreous cavity and from the conjunctival sac were collected for bacteriologic studies.
  
  
  RESULTS
  Positive cultures from extraocular fluids were obtained in 30.4% of the gentamicin group and 35.3% of the placebo group (P = .75). Furthermore, 1 (3%) of 40 cultures of intraocular fluid and 13 (33%) of 40 cultures of extraocular fluid were positive. Culture growth positivity was not influenced by the patients' age, by diabetes, or by the duration of the operation.
  
  
  CONCLUSIONS
  Prophylactic gentamicin treatment by the method applied in this study is not effective on reducing growth positivity. Contaminated extraocular fluid may play an important role in the pathogenesis of bacterial endophthalmitis following pars plana vitrectomy.
authors.affiliation: Department of Ophthalmology, Rambam Medical Center, Haifa, Israel.
authors.forename: Y A
authors.initials: YA
authors.lastname: Gelfand
authors.forename: E
authors.initials: E
authors.lastname: Mezer
authors.forename: S
authors.initials: S
authors.lastname: Linn
authors.forename: B
authors.initials: B
authors.lastname: Miller
mesh_terms: D000287:Administration, Topical; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D019072:Antibiotic Prophylaxis; D001419:Bacteria / Q000302:isolation & purification*; D015169:Colony Count, Microbial; D003228:Conjunctiva / Q000382:microbiology*; D004311:Double-Blind Method; D015818:Eye Infections, Bacterial / Q000517:prevention & control; D005260:Female; D005839:Gentamicins / Q000008:administration & dosage*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009883:Ophthalmic Solutions; D011446:Prospective Studies; D014821:Vitrectomy / Q000009:adverse effects; D014822:Vitreous Body / Q000382:microbiology*
chemical_list: D000900:Anti-Bacterial Agents; D005839:Gentamicins; D009883:Ophthalmic Solutions