A 77-YEAR-OLD man developed a deep infiltrate in a corneal graft 7 years after undergoing penetrating keratoplasty for pseudophakic bullous keratopathy. Medical history revealed mild trauma to the eye while cutting grass several months before the initial visit. The infiltrate was thought to be sterile based on clinical appearance. It worsened over 4 weeks while the patient was receiving intensive treatment with topical ofloxacin, and then topical steroids (Figure 1). An epithelial defect was created over the infiltrate to obtain scrapings for smears and cultures. The initial Gram stain was identified as gram-positive filaments, possibly Nocardia species (Figure 2). Final cultures grew nontuberculous Mycobacterium chelonae. Test results showed sensitivity to amikacin, clarithromycin, and sulfamethoxazole-trimethoprim, with resistance to ciprofloxacin and imipenem. Hourly topical amikacin sulfate (initially 15 mg/mL, then 40 mg/mL) combined with oral sulfamethoxazole-trimethoprim (twice daily) administered for 3 months, followed by oral clarithromycin (500 mg twice daily) for 4 weeks resulted in total resolution of the infiltrate (Figure 3). The graft has remained clear at 7 months' follow-up after treatment with all medications were discontinued.
Sudesh S, Cohen EJ, Schwartz LW, Myers JS. Mycobacterium chelonae Infection in a Corneal Graft. Arch Ophthalmol. 2000;118(2):294. doi:10.1001/archopht.118.2.294