Role of topical antibiotics to prevent endophthalmitis after intravitreal anti-vascular endothelial growth factor injection

Background: Age-related macular degeneration (AMD) is the leading cause of severe vision loss in older people in the United States. Neovascular (or “exudative” or “wet”) AMD accounts for more than 80% of severe vision caused by AMD. Monthly intravitreal anti-vascular endothelial growth factor medication injections have been shown to halt progression of neovascular AMD and significantly improve vision. However, ocular injections can cause intraocular infection (endophthalmitis), which can lead to severe vision loss. The utility of topical antibiotics to prevent endophthalmitis following intravitreal injection is unclear.

Methods: A retrospective review of intravitreal injections administered at one large retina practice between January 1, 2009 and October 1, 2012 was performed. For the first 32 months of the study period, topical antibiotics were prescribed for 4 to 5 days post-injection. During the remaining 13 months of the study, topical antibiotics were not prescribed. The rates of endophthalmitis between the two time periods were analyzed.

Results: A total of 104,870 injections were administered to 13,568 patients during the study period. Post-injection topical antibiotics were prescribed after 63,147 of the injections. Thirty-one cases of endophthalmitis occurred in this group (incidence rate 0.049%). Antibiotics were not given following 41,723 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).

Conclusion: The incidence of endophthalmitis following intravitreal injection is low. Routine use of post-injection antibiotic drops does not appear to significantly reduce the risk of developing endophthalmitis.