Therapeutic Femtosecond Laser-Assisted Lamellar Keratectomy for Multidrug-Resistant Nocardia Keratitis

Purpose: To describe the novel use of femtosecond laser technology for therapeutic resection of infectious foci in a case of multidrug-resistant Nocardia asteroides keratitis. Methods: A 30-year-old man presented with a corneal infiltrate. Cultures were taken, and fortified vancomycin and tobramycin were initiated. After 3 negative cultures and minimal improvement on various broad-spectrum antibiotics, all topical medications were stopped and a final fourth corneal culture grew N. asteroides. Treatment with topical amikacin was initiated, but the infection continued to worsen. With drug sensitivities still pending, the patient's clinical status continued to deteriorate rapidly, despite treatment with amikacin, gatifloxacin, and polymyxin B/trimethoprim. The femtosecond laser was then used to perform targeted lamellar keratectomy. Results: Femtosecond laser-assisted lamellar keratectomy successfully removed the infected tissue and allowed for increased penetration of topical antibiotics. Drug sensitivities finally returned, revealing multidrug resistance and sensitivity only to trimethoprim/sulfamethoxazole and tobramycin, some of which the patient had previously tried and failed. The infection fully resolved after readministering polymyxin B/trimethoprim and tobramycin, leaving minimal residual scarring. Conclusions: Multidrug-resistant N. asteroides keratitis can be difficult to manage even with appropriate antibiotic therapy based on drug sensitivity testing. Femtosecond laser-assisted resections may facilitate treatment in these cases by safely and precisely debulking infected tissue and enhancing penetration of topical medications.