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.
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.
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).
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.
*Retina Consultants of Houston, Houston, Texas; and
†Blanton Eye Institute and Houston Methodist Hospital, Houston, Texas.
Reprint requests: Charles C. Wykoff, MD, PhD, 6560 Fannin Street, Suite 750, Houston, TX 77030; e-mail: email@example.com
None of the authors have any financial/conflicting interests to disclose.