Methicillin-Resistant Staphylococcus aureus Keratitis after Descemet's Stripping Automated Endothelial Keratoplasty
An 87-year-old woman who had undergone a DSAEK 4 months previously and received topical steroids as one of the perioperative medications presented to a medical practitioner with discharge and conjunctival hyperemia of the right eye. During the period between 3 days before surgery and 1 month after surgery, topical gatifloxacin ophthalmic solution (Gatiflo® 0.5% ophthalmic solution, Senju Pharmaceutical, Co., Ltd., Osaka, Japan) had been administered 4 times daily. The topical steroids were withheld and she was referred to Tokushima University Hospital with a diagnosis of infectious keratitis after DSAEK. At the first visit, slit-lamp microscopy revealed a white abscess and infiltration in the inferior cornea of the right eye (fig. ). Examination of a cross-section of the infected cornea on anterior-segment optical coherence tomography suggested that the abscess was located only in the recipient cornea (fig. ). The best-corrected visual acuity (BCVA) was hand motion. A corneal scraping revealed Gram-positive cocci, and empiric therapy was started with frequent administration of both 1.5% levofloxacin (LVFX; Cravit® 1.5% ophthalmic solution, Santen Pharmaceutical, Co., Ltd., Osaka, Japan) and 0.25% chloramphenicol with 100,000 U/ml of colistin sodium methanesulfonate ophthalmic solutions (CP/CL; Ophthalon® ophthalmic solution, Wakamoto, Co., Ltd., Tokyo, Japan). Methicillin-resistant Staphylococcus aureus (MRSA) was isolated from the corneal scraping. Although the strain of MRSA was resistant to quinolone, it was susceptible to chloramphenicol (table ). Since the empiric treatment worked and minimal inhibitory concentrations (MICs) were determined for systemic administration, the treatment was continued. The corneal infectious lesion rapidly decreased in size, allowing resumption of topical steroids 6 days after initiation of the empiric therapy. Although the corneal endothelial cell densities before and after medication were 2,193 and 813 cells/mm2, respectively, both the endothelial graft and the recipient cornea were thin and clear (fig. ). The BCVA improved to 6/20. The infection has not recurred so far.