The role of antibiotic prophylaxis to prevent post-injection endophthalmitis

Abstract

Purpose: To compare the incidence of endophthalmitis following intravitreal injection of anti-vascular endothelial growth factors agents and triamcinolone acetonide with and without post-injection antibiotic prophylaxis.

Methods: Retrospective review of intravitreal injections administered at one large retina practice between January 1, 2009 and October 1, 2012. The total number of injections was determined from billing code records. Injections were performed for a variety of retinal vascular diseases. For the first 32 months of the study period, topical antibiotics were prescribed for 4 to 5 days depending on physicians preference. During the remaining 13 months of the study period, topical antibiotics were not prescribed.

Results: A total of 104870 injections (61182 ranibizumab, 39376 bevacizumab, 4312 triamcinolone acetonide) were given during the study period. Post-injection topical antibiotics were prescribed in 63147 of the injections. Thirty-one cases of endophthalmitis occurred in this group (incidence rate 0.049%). Antibiotics were not given following 41723 injections, among which 13 cases of endophthalmitis occurred (incidence rate 0.031%). Incidence of endophthalmitis for patients prescribed topical antibiotics was not significantly different from patients not using antibiotics (p=0.17). No statistically significant difference in incidence of endophthalmitis between the intravitreal medications was identified.

Conclusions: The incidence of endophthalmitis following intravitreal injection is low. Post-injection antibiotic drops do not appear to significantly reduce the risk of developing endophthalmitis.

Keywords: 513 endophthalmitis • 561 injection • 688 retina