title: Cluster of Mycobacterium chelonae keratitis cases following laser in-situ keratomileusis.
abstract: OBJECTIVE
  To describe a cluster of Mycobacterium chelonae keratitis cases involving patients who underwent laser in-situ keratomileusis (LASIK) at a single refractive surgery center.
  
  
  METHODS
  Descriptive case series of four patients and cohort study to identify disease associations.
  
  
  METHODS
  Examination schedules, diagnostic tests, and therapy were based on best medical judgment. Isolates from three patients were compared by pulsed-field gel electrophoresis. Epidemiologic studies were performed to identify the source of infection.
  
  
  RESULTS
  Seven of eight eyes developed M. chelonae keratitis following bilateral simultaneous LASIK. Each patient was thought to have diffuse lamellar keratitis initially, but all seven eyes were noted to have opacities suggestive of infectious keratitis by 13 to 21 days after surgery. All eyes had undergone hyperopic LASIK over four days in April 2001 by one surgeon in a community-based refractive surgery center. A cohort study of all patients undergoing LASIK at the same center in April 2001 revealed that M. chelonae keratitis occurred only in persons undergoing correction of hyperopia (seven of 14 eyes vs. none of 217 eyes undergoing myopic LASIK, P <.001). The only difference identified between procedures was use of masks created from a soft contact lens in hyperopic LASIK. Three isolates (three patients) were indistinguishable by pulsed-field gel electrophoresis. Eyes were treated with a combination of antimicrobial agents, including topical azithromycin in three patients, with resolution of infection in all eyes over 6 to 14 weeks. The source of infection was not identified on environmental cultures.
  
  
  CONCLUSIONS
  Postoperative nontuberculous mycobacterial keratitis can occur in an epidemic fashion following LASIK. Topical amikacin, azithromycin, clarithromycin, ciprofloxacin, or a combination of these agents, appears to be effective treatment for these infections.
authors.affiliation: Ocular Inflammatory Disease Center, Jules Stein Eye Institute, Department of Ophthalmology, UCLA School of Medicine, Los Angeles, CA, USA.
authors.forename: N S
authors.initials: NS
authors.lastname: Chandra
authors.forename: M F
authors.initials: MF
authors.lastname: Torres
authors.forename: K L
authors.initials: KL
authors.lastname: Winthrop
authors.forename: D A
authors.initials: DA
authors.lastname: Bruckner
authors.forename: D G
authors.initials: DG
authors.lastname: Heidemann
authors.forename: H M
authors.initials: HM
authors.lastname: Calvet
authors.forename: M
authors.initials: M
authors.lastname: Yakrus
authors.forename: B J
authors.initials: BJ
authors.lastname: Mondino
authors.forename: G N
authors.initials: GN
authors.lastname: Holland
mesh_terms: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins / Q000032:analysis; D002140:California; D016000:Cluster Analysis; D015331:Cohort Studies; D003315:Cornea / Q000382:microbiology / Q000601:surgery; D004359:Drug Therapy, Combination / Q000627:therapeutic use; D016521:Electrophoresis, Gel, Pulsed-Field; D015818:Eye Infections, Bacterial / Q000188:drug therapy / Q000453:epidemiology / Q000209:etiology* / Q000382:microbiology; D005260:Female; D006801:Humans; D006956:Hyperopia / Q000601:surgery; D007634:Keratitis / Q000188:drug therapy / Q000453:epidemiology / Q000209:etiology* / Q000382:microbiology; D020731:Keratomileusis, Laser In Situ / Q000009:adverse effects*; D008875:Middle Aged; D009165:Mycobacterium Infections, Nontuberculous / Q000188:drug therapy / Q000453:epidemiology / Q000209:etiology* / Q000382:microbiology; D016926:Mycobacterium chelonae / Q000302:isolation & purification*
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins