Abstract
Purpose:
To determine if intravitreal injections are conducted in a properly sterilized environment. Endophthalmitis is the most feared complication of intravitreal injections. Conventionally, anti-septics without antibiotics are used to sterilize the conjunctival surface before injections. This study investigates the effect of Maxitrol (neomycin and polymyxin B sulfates and dexamethasone ophthalmic suspension) on bacterial isolates when used in addition to betadine 5%.
Methods:
This is a randomized prospective study from 2011-2012 at the University of Louisville School of Medicine Department of Ophthalmology. Eighty-six patients requiring intravitreal injections were enrolled in the study, with 110 eyes randomized into 55 control sample and 55 treatment sample. A swab culture was obtained on all eyes before any anti-bacterial or anti-septic application. A second swab culture was obtained post application of the sterilizing agents and/or antibiotic. Sensitivities were obtained and the cultures from each group were counted and compared. Statistical analysis was performed using SASS.
Results:
Conjunctival swab cultures were initially obtained from 110 eyes. 50 swabs from untreated eyes grew bacteria (n=110, 45%). 55 eyes were then treated with betadine 5% and the other 55 eyes were treated with a combination of Maxitrol and Betadine 5%. 20 swabs from eyes treated without Maxitrol grew bacteria while 8 swabs treated with Maxitrol grew bacteria (n=110, p-value=0.0084). The most common bacteria isolated was coagulase negative staphylococcus (CNS) (63 %). 15 (75%) swabs from eyes treated without Maxitrol grew CNS while 4 (50%) swabs from Maxitrol treated eyes grew CNS (n=110, p-value=0.0098).
Conclusions:
Significant reduction in endophthalmitis causing organisms were observed in the group treated with both Maxitrol and betadine. In patients receiving intravitreal injections, preparing the injection site with a combination of betadine and Maxitrol may reduce the incidence of inadvertent infectious complications.