Abstract
Purpose:
To determine whether conjunctival flora develop antibiotic resistance after serial intravitreal injections when topical post-injection antibiotic drops are not used.
Methods:
New patients with neovascular age-related macular degeneration or retinal vein occlusion requiring serial intravitreal injections (≥ 3) were randomized to receive either topical ofloxacin 0.3% and 5% povidone-iodine, or 5% povidone-iodine alone, for pre-injection ocular surface preparation. Conjunctival cultures were performed prior to each injection preparation. Conjunctival flora antibiotic resistance patterns were compared between groups as well as within each group over the course of the study.
Results:
Twenty-four patients completed the study with 12 patients assigned to each group. Eighty-six cultures were performed with a 76% culture positivity rate. The most frequent organism isolated from positive cultures was coagulase negative staphylococcus (83%). The change in antibiotic resistance between the two groups over the course of the study was not statistically significant (P=0.13). Furthermore, there was no evidence that the incidence of resistance increased within either group over the course of the study.
Conclusions:
Ocular surface preparation for intravitreal injection with povidone-iodine alone or in conjunction with topical fluoroquinolones, in the absence of post-injection antibiotics, does not significantly promote antibiotic resistance.
Keywords: 422 antibiotics/antifungals/antiparasitics