Cluster of Mycobacterium chelonae keratitis cases following laser in-situ keratomileusis

- PURPOSE: To describe a cluster of Mycobacterium chelonae keratitis cases involving patients who underwent laser in-situ keratomileusis (LASIK) at a single refractive surgery center. - DESIGN: Descriptive case series of four patients and cohort study to iden tify disease associations. - METHODS: Examination schedules, diagnostic tests, and therapy were based on best medical judgment. Isolates from three patients were compared by pul sed-field gel electrophoresis. Epidemiologic studies were per, formed to id entify the source of infection. - RESULTS: Seven of eight eyes developed M. chelonae keratitis following bi lateral simultaneous LASIK. Each patient was thought to have diffuse lamell ar keratitis initially, but all seven eyes were noted to have opacities sug gestive of infectious keratitis by 13 to 21 days after surgery. All eyes ha d undergone hyperopic LASIK over four days in April 2001 by one surgeon in a community, based refractive surgery center. A cohort study of all patient s undergoing LASIK at the same center in April 2001 revealed that M. chelon ae keratitis occurred only in persons undergoing correction of hyperopia (s even of 14 eyes vs. none of 217 eyes undergoing myopic LASIK, P < .001). Th e only difference identified between procedures was use of masks created fr om a soft contact lens in hyperopic LASIK. Three isolates (three patients) were indistinguishable by pulsed-field gel electrophoresis. Eyes were treat ed with a combination of antimicrobial agents, including topical azithromyc in in three patients, with resolution of infection in all eyes over 6 to 14 weeks. The source of infection was not identified on environmental culture s. - CONCLUSION: Postoperative nontuberculous mycobacterial keratitis can occu r in an epidemic fashion following LASIK Topical amikacin, azithromycin, cl arithromycin, ciprofloxacin, or a combination of these agents, appears to b e effective treatment for these infections. (C) 2001 by Elsevier Science In c. All rights reserved.