M chelon Keratitis After LASIK Surgery
Abstract & Commentary
Synopsis: Ten patients undergoing LASIK procedures at a single laser surgery center in Sao Paulo, Brazil, suffered corneal infection due to Mycobacterium chelonae.
Source: Freitas D, et al. An outbreak of Mycobacterium chelonae infection after LASIK. Ophthalmology. 2003;110: 276-285.
Freitas and colleagues report on 10 patients undergoing laser in situ keratomileusis (LASIK) for correction of refractive errors performed by a single surgeon at a laser surgical center during a 2-week period. At an average of 10 days after the procedure (range, 3-25), the patients returned with blurred vision, tearing, erythema, and photophobia. One patient had infection of both eyes. Examination of the cornea showed white infiltrates. Initial cultures done by the surgeon were reported as growing Nocardia species. He initiated treatment with multiple topical antimicrobial agents, topical corticosteroids, and oral trimethoprim-sulfamethoxazole. When the patients’ symptoms worsened, they were referred to the University of Sao Paulo for further treatment. Corneal cultures there revealed Mycobacterium chelonae. Based on susceptibility studies, the patients were treated with an intensive topical regimen consisting of tobramycin, clarithromycin, and ofloxacin every hour until there was clinical improvement. The frequency of administration was then tapered to every 3 hours. All patients developed recurrent episodes (range, 1-4), which were treated by intensification of the topical regimen, addition of oral clarithromycin, and surgical debridement. Although all patients were eventually cured, most suffered permanent loss of vision due to corneal scarring, with best corrected vision of 20/25 to 20/100 (median, 20/50). Five patients also had uncorrectable astigmatism due to corneal scarring.
Water samples from the portable steamer used to clean the microkeratome, as well as from the air conditioning system of the surgical center, grew M chelonae.
Comment by Robert Muder, MD
LASIK is an increasingly popular surgical procedure used to correct visual refractive errors. The procedure involves cutting a flap in the corneal epithelium with a laser. The laser is then used to remove tissue from the corneal stroma, thus changing the refractive characteristics of the cornea. These procedures are often performed at free-standing laser surgical centers. Although infection is an uncommon complication, a variety of pathogens, including Staphylococcus aureus, S epidermidis, streptococci, Nocardia spp., and fungi have been reported.
Nontuberculous mycobacterial infection following LASIK may occur as sporadic cases or as outbreaks; implicated mycobacterial species include M chelonae, M fortuitum, M gordonae, and M szulgai. A previous cluster in California involved 7 patients infected with M chelonae.1 Infection was highly associated with use of a soft contact lens as a corneal mask during the procedure; the source of the organism was not identified. As in the cluster reported by Freitas et al, patients required protracted courses of antimicrobial therapy, with several undergoing debridement procedures. All had some uncorrectable loss of visual acuity, with best corrected vision ranging from 20/25 to 20/200.
Nontuberculous mycobacteria are widely distributed in soil and water. Hospital water supplies, or devices using nonsterile water, are potential reservoirs of nosocomial infection. Mycobacterial infection following LASIK surgery may be more common than previously appreciated. A recent survey by the American Academy of Ophthalmologists of its membership identified 35 cases occurring over a 10-month period; thirty-one of these were part of 2 outbreaks not previously reported to the CDC.2 One of the outbreaks, due to M szulgai, was traced to contaminated ice, made with tap water that was used to chill the saline solution used in the procedure.
These reports illustrate several important points. The first is that novel surgical procedures are often followed by novel surgical site infections. The second is that nonsterile water should not be used in invasive procedures. Tap water, and devices using tap water, harbor a variety of potential pathogens, including mycobacteria, nonfermentative Gram-negative bacilli, fungi, and Legionella. Introduction of these organisms into a critical site such as the eye can have disastrous consequences. Finally, an increasing number of surgical procedures are being performed in free-standing surgical facilities that may not come under the supervision of an effective infection control program. Whether or not this trend will be followed by an increase in nosocomial infection remains to be determined.
Dr. Muder is Hospital Epidemiologist Pittsburgh VA Medical Center Pittsburgh Section Editor, Hospital Epidemiology.
References
1. Chandra NS, et al. Cluster of Mycobacterium chelonae keratitis cases following laser in-situ keratomileusis. Am J Ophthalmol. 2001;132:819-829.
2. Winthrop KL, et al. Epidemic and sporadic cases of nontuberculous mycobacterial keratitis associated with laser in situ keratomileusis. Am J Ophthalmol. 2003;135:223-224.
Ten patients undergoing LASIK procedures at a single laser surgery center in Sao Paulo, Brazil, suffered corneal infection due to Mycobacterium chelonae.You have reached your article limit for the month. Subscribe now to access this article plus other member-only content.
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