Bacterial Keratitis Caused by Methicillin-Resistant Coagulase-Negative Staphylococci After Cultured Human Corneal Endothelial Cell Injection: A Case Report and Review of Preoperative Conjunctival Sac Culture Findings

Purpose: The aim of this study was to report a case of methicillin-resistant coagulase-negative staphylococci (MRCNS) keratitis after cultured human corneal endothelial cell (cHCEC) injection therapy, in which MRCNS with similar antimicrobial susceptibility profiles were identified on both preoperative conjunctival sac and postoperative corneal scraping cultures. Methods: We report a case of infectious keratitis following cHCEC injection therapy and retrospectively reviewed preoperative conjunctival sac culture results in 51 consecutive patients who underwent the procedure at our institution. Results: A 75-year-old man with bullous keratopathy underwent cHCEC injection therapy. Preoperative conjunctival sac culture revealed fluoroquinolone-resistant MRCNS. On postoperative day 7, 2 circular corneal infiltrates were identified in the superior cornea with worsening corneal edema. Corneal scraping culture again yielded MRCNS with similar antimicrobial susceptibility profiles, supporting the diagnosis of postoperative MRCNS keratitis. Topical chloramphenicol/colistin methanesulfonate sodium and cefmenoxime led to rapid resolution of the infiltrates. At 3 months postoperatively, the infection had resolved and best corrected visual acuity improved to 20/63 (logMAR 0.50). In the retrospective review of 51 patients, positive conjunctival sac cultures were observed in 27 (52.9%), including MRCNS in 8 (15.7%). Fluoroquinolone resistance was noted in 23 patients (45.1%) for levofloxacin and 21 (41.2%) for gatifloxacin. Conclusions: Infectious keratitis can occur early after cHCEC injection therapy. Preoperative conjunctival sac culture may be useful in guiding empirical antimicrobial therapy when fluoroquinolone-resistant organisms are present. However, larger studies are needed to determine whether routine preoperative conjunctival sac culture is warranted in patients undergoing cHCEC injection therapy.