LASIK-associated Atypical Mycobacteria Keratits: A Case Report and Review of the Literature
We report a case of a 25-year-old man with past surgical history of myopic laser in situ keratomileusis (LASIK) surgery in both eyes in 2004 and an enhancement 1 year later on his right eye on the VISX S4 Excimer laser (Santa Clara, CA). The patient had a history of anisometropic amblyopia and his preoperative refraction was −5.25 sphere OD and −17 sphere OS. His target correction with laser vision correction was plano OU. Immediately after his initial LASIK surgery, his uncorrected visual acuity was 20/15 in his right eye, and improvement over his preoperative best spectacle corrected visual acuity to 20/70 in his left eye. One year after the initial treatment, the patient experienced minor regression (−1.25 sphere) in his right eye and requested an enhancement. A LASIK retreatment on the right side was performed improving uncorrected vision to 20/15. Topical commercial gatifloxacin (Zymar, Allergan, Irvine, CA) was used as postoperative antiobiosis. Approximately, 2 weeks after the enhancement, the patient began to experience foreign body sensation in his right eye without significant change in vision. However, 3 days later, owing to the lingering symptoms, the patient was seen by the refractive surgeon who noted a 3-mm intralamellar infiltrate with significant hyperemia. During that same visit, the LASIK flap was lifted, the intrastromal bed was scraped for cultures and the interface was irrigated with balanced salt solution and commercial gatifloxacin before flap repositioning. He was subsequently started on gatifloxacin every 2 hours and ciprofloxacin ointment at bed time while the scrapings were sent for cultures. The course of the infiltrate was indolent with initial improvement of the infiltrate 3 days after lifting the flap, subsequently followed by development of clinically appearing diffuse lamellar keratitis (DLK). This was treated with topical prednisolone acetate that initially improved interface haze but eventually eroded to redevelopment of the infiltrate. After the initial clinical improvement, the patient's vision deteriorated of to 20/400 with worsening pain and photophobia. Because of his deteriorating clinical course, a decision was made to relift the flap, reculture, and reirrigate the intrastromal bed with commercial gatifloxacin. The day after the flap was lifted for a second time, the refractive surgeon received a report of positive growth for atypical mycobacteria from the initial cultures. Topical Amikacin was initiated with continued use gatifloxacin alternating every 2 hours and termination of topical corticosteroids. Two days after altering the treatment plan, the density of the infiltrate decreased but eventually deteriorated with a diffuse “cracked windshield” pattern of infiltrate throughout the cornea. Three weeks after the problem started, the patient was referred to the Cornea and Refractive Surgery Service at the Massachusetts Eye and Ear Infirmary for evaluation with count fingers vision in the right eye. Examination revealed an infiltrate displaying diffuse intrastromal haze, with an infiltrate involving the visual axis with a cracked windshield appearance as shown in Figure 1. Knowing of the previous atypical mycobacteria cultures and the history of progression with apparent penetration of the flap by the infiltrate, a decision was made to lift and amputate the LASIK flap. The decision to amputate the flap was 2-fold; first, to lower the bacterial load by removing necrotic as well as infected tissue, and second, to allow for better antibiotic penetration for potential eradication of the bacteria from the cornea. During this procedure, the flap was amputated and the stromal bed was soaked in gatifloxacin 0.3% solution for 5 minutes. The tissue was removed and sent for cultures, which grew abundant atypical mycobacteria identified (Fig. 2) as Mycobacteria chelonae at the Centers for Disease Control in Atlanta.