Endophthalmitis following cataract surgery and intracameral antibiotic: Moxifloxacin resistant Staphylococcus epidermidis

PURPOSE: To describe an immunosuppressed patient who developed acute-onset postoperative endophthalmitis caused by a moxifloxacin-resistant strain of Staphylococcus epidermidis after cataract surgery despite the use of intracameral moxifloxacin. OBSERVATIONS: A 76-year old woman with a history of birdshot chorioretinopathy controlled on systemic immunosuppression underwent uneventful cataract surgery in her right eye. Compounded intracameral moxifloxacin 0.2 cc of 1mg/0.1mL (Edge Pharmacy, Syracuse, NY) was injected intraoperatively as prophylaxis, and the patient was placed on a standard regimen of trimethoprim-polymyxin b (10000-0.1unit/mL) and prednisolone acetate 1% postoperatively. Four days later, the patient experienced a sudden decrease in vision in the right eye. Anterior chamber inflammation, vitritis, and vasculitis were seen in the operated eye. The patient underwent a vitreous tap and intravitreal injections of vancomycin (1mg/0.1mL), ceftazidime (2.25mg/0.1mL), and dexamethasone (0.4mg/0.1mL). Cultures grew Staphylococcus epidermidis, resistant to moxifloxacin (MIC ≥8mg/L). The inflammation resolved over two months. Eight months later, the patient underwent uncomplicated cataract surgery in the left eye. Intracameral antibiotics were not used, however her systemic immunosuppressive therapy was held for several weeks perioperatively. One year after the initial surgeries, the patient had an uncorrected visual acuity of 20/20 in each eye. CONCLUSIONS AND IMPORTANCE: S. epidermidis, the most common cause of postoperative endophthalmitis, is increasingly resistant to fluoroquinolones. Adequate concentrations of intracameral antibiotics need to be achieved in order to exceed minimal inhibitory concentration values of the targeted pathogen. Although intracameral moxifloxacin has been reported to decrease the rate of endophthalmitis after cataract surgery, it does not eliminate the risk.