Boston type I Keratoprosthesis: Antibacterial Resistance and Microbiota Evaluation of Soft Contact Lenses

Abstract Purpose To evaluate microbiota colonizing soft contact lenses (CL) in eyes with Boston type I keratoprosthesis (BKPro), and determine the prevalence of resistance to fourth-generation fluoroquinolone (FQ). Design Prospective, observational study. Subjects Patients with BKPro using CL as routine who were in postoperative follow-up in the department of ophthalmology from Federal University of Sao Paulo, and volunteered to participate in the study. All patients were under prophylactic scheme of topical 0.5% moxifloxacin 3 times a day and topical 5% povidone-iodine (PI) at the time of CL exchange. Methods Patients on scheduled replacement scheme of CL, had their lenses removed and sent for microbiological analysis. Standard culture methods were used for microorganism identification and susceptibility to different antibiotics was tested. Main Outcome Measure Prevalence of resistance to fourth-generation FQ. Results Among the 19 eyes, 12 eyes (63%) had at least one positive bacterial culture. The most prevalent isolates were Staphylococci epidermidis and other coagulase-negative Staphylococci . Actinomyces viscosus was isolated in one CL. Fungal cultures were all negative. Of the 12 eyes with culture bacterial growth, resistance to fourth-generation FQ (0.5% moxifloxacin) was identified in 6 different eyes (50%). None presented infectious complications. Conclusions FQ-resistant bacteria were isolated in some patients. Although our prophylactic antibiotic regime has been efficient in preventing bacterial infection, this analysis demonstrated that prophylaxis with PI and low FQ dose might increase resistance to antibiotics. Investigations in this field may help to outline future changes of prophylactic guidelines and therapeutic strategies.