ENDOPHTHALMITIS AFTER INTRAVITREAL INJECTION

Abstract

In Brief Purpose: To determine the rate of postintravitreal injection endophthalmitis and to assess microbiological features and outcomes with and without the use of peri-intravitreal injection topical ophthalmic antibiotics. Methods: Consecutive series of endophthalmitis cases retrospectively identified after intravitreal injection at a multicenter, retina-only referral practice (Retina Consultants of Houston) from January 1, 2011 to December 31, 2014. Prophylactic peri-intravitreal injection topical antibiotics were routinely used during the initial 12-month period (January 1, 2011–December 31, 2011) and not used in the final 24-month period (January 1, 2013–December 31, 2014). Main outcome measures were incidence of endophthalmitis, microbiology results, treatment strategies, and visual outcomes. Results: Of 90,339 intravitreal injections, 30 cases of endophthalmitis were identified (endophthalmitis rate = 0.033%; 95% confidence interval, 0.021–0.045%; or approximately 1 of 3,011 intravitreal injections). The most common organisms isolated were coagulase-negative staphylococci (n = 10, 33%), followed by Streptococcus mitis (n = 2, 7%). Fourteen cases (47%) were culture negative. Peri-intravitreal injection topical antibiotic prophylaxis did not decrease the rate of endophthalmitis (0.035% [95% CI, 0.007–0.064%] with antibiotic use versus 0.021% [95% CI, 0.008–0.033%] without antibiotic use; P = 0.261). Conclusion: The risk of endophthalmitis after intravitreal injection remains low, with coagulase-negative staphylococci and Streptococcus mitis the most common bacterial isolates identified. Prophylactic peri-intravitreal injection topical ophthalmic antibiotic use did not decrease the endophthalmitis rate. In this consecutive case series of 90,339 intravitreal injections from a large, office-based retina practice, the rate of postinjection clinically suspected endophthalmitis was 0.033%, and the most common microbiological isolates were staphylococcal and streptococcal species. Prophylactic peri-intravitreal injection topical ophthalmic antibiotic use did not affect the rate of endophthalmitis.