title: Perioperative microbiologic profile of the conjunctiva in photorefractive keratectomy.
abstract: OBJECTIVE
  Therapeutic soft contact lenses are used commonly as an adjunctive treatment after photorefractive keratectomy (PRK) to decrease postoperative pain caused by the movement of lids over the corneal epithelial defect and to facilitate epithelial healing. We assessed the microbiological profile of the conjunctiva of patients undergoing PRK for myopia, before and after the concurrent use of a therapeutic soft contact lens, and compared the effect on ocular bacterial colonization of prophylactic administration of topical tobramycin 0.3% versus ofloxacin 0.3%.
  
  
  METHODS
  Forty-three consecutive eyes from 37 patients underwent PRK for myopia or myopic astigmatism. Eyes were assigned randomly to prophylactic antibacterial treatment with either topical ofloxacin 0.3% or tobramycin 0.3%, applied prior to surgery and three times daily after surgery until therapeutic soft contact lens removal. Material from the conjunctival sac was obtained for bacteriologic cultures prior to surgery. Clinical evaluation of all eyes was conducted prospectively. Three days after PRK, the therapeutic soft contact lenses were removed and cultured. Cultures from the conjunctival sac were then repeated.
  
  
  RESULTS
  No statistically significant differences were observed in culture positivity between the two groups of eyes, in spite of some positive preoperative and postoperative cultures. Only one out of 43 eyes (assigned to the ofloxacin group) developed a peripheral corneal infiltrate. The corneal infiltrate healed completely without sequelae using antibiotic and corticosteroid therapy.
  
  
  CONCLUSIONS
  The use of therapeutic soft contact lenses after PRK with either topical tobramycin 0.3% or ofloxacin 0.3% were well tolerated. However, perioperative positive conjunctival cultures were relatively frequent and prophylactic antibiotics should be used in the setting of an epithelial defect and therapeutic soft contact lens following PRK.
authors.affiliation: Refractive Surgery Service, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21093, USA.
authors.forename: I S
authors.initials: IS
authors.lastname: Barequet
authors.forename: N S
authors.initials: NS
authors.lastname: Jabbur
authors.forename: Y
authors.initials: Y
authors.lastname: Barron
authors.forename: G J
authors.initials: GJ
authors.lastname: Osterhout
authors.forename: T P
authors.initials: TP
authors.lastname: O'Brien
mesh_terms: D000328:Adult; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000627:therapeutic use; D000890:Anti-Infective Agents / Q000008:administration & dosage / Q000627:therapeutic use; D019072:Antibiotic Prophylaxis; D001251:Astigmatism / Q000382:microbiology / Q000601:surgery; D001419:Bacteria / Q000302:isolation & purification; D003228:Conjunctiva / Q000382:microbiology*; D003261:Contact Lenses; D003315:Cornea / Q000382:microbiology / Q000601:surgery*; D015818:Eye Infections, Bacterial / Q000382:microbiology* / Q000517:prevention & control; D005260:Female; D006801:Humans; D054018:Lasers, Excimer; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000382:microbiology / Q000601:surgery*; D015242:Ofloxacin / Q000008:administration & dosage / Q000627:therapeutic use; D009883:Ophthalmic Solutions; D018903:Photorefractive Keratectomy; D011446:Prospective Studies; D014031:Tobramycin / Q000008:administration & dosage / Q000627:therapeutic use
chemical_list: D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D009883:Ophthalmic Solutions; D015242:Ofloxacin; D014031:Tobramycin