A cluster of cases of Mycobacterium szulgai keratitis that occurred after laser-assisted in situ keratomileusis

Laser-assisted in situ keratomileusis (LASIK) is a recently developed ophthalmic procedure. When 2 patients developed keratitis caused by Mycobacterium szulgai after they underwent LASIK surgery, we conducted a retrospective cohort study of all LASIK procedures performed at Scott & White Clinic (Temple, Texas) during a 4.5-month period. Seven patients had compatible symptoms and signs, 5 of whom had confirmed M. szulgai keratitis. Five cases occurred among 30 procedures performed by doctor A, and there were no cases among 62 procedures performed by doctor B (approximate relative risk, 12.0; 95% confidence interval, 1.6-679.0;). Doctor A had chilled syringes of saline solution in ice for intraoperative lavage-the only factor P = .0029 that differentiated the procedures of the 2 surgeons. Cultures of samples from the source ice machine's drain identified M. szulgai; the strain was identical to isolates recovered from all confirmed cases and differed from 4 standard M. szulgai strains, as determined by pulsed-field gel electrophoresis. Intraoperative contamination from ice water apparently led to M. szulgai keratitis in these patients.