Impact of Antibiotic Prophylaxis on the Conjunctival Flora of Patients Receiving Intravitreal Antivascular Endothelial Growth Factor Injections

Abstract

Purpose: To characterize the conjunctival flora of patients receiving antibiotics before intravitreal (IVT) antivascular endothelial growth factor injections. Methods: We studied 31 eyes of 30 patients with neovascular age-related macular degeneration scheduled to receive IVT antivascular endothelial growth factor injections. The patients were all given a preinjection of topical ofloxacin 3 days before the injections. Conjunctival cultures from the injection eye were collected before antibiotic prophylaxis (sample A) and on the injection day, both before (sample B) and after (sample C) povidone-iodine (PVI) application. Results: Culture positivity was significantly different between samples A (50%) and C (4.5%; p < 0.001) as well as samples B (30.4%) and C (4.5%; p = 0.015), but not between samples A and B. Positive cultures were mainly coagulase-negative staphylococci (CNS; 57% of sample A, 62.5% of sample B and 100% of sample C) susceptible to vancomycin (100%), moxifloxacin (90%), levofloxacin (70%) and ofloxacin (60%). Conclusion: In our study, most of the bacteria isolated were CNS. PVI application but not antibiotics reduced culture positivity.