Purpose: The purpose was to compare the incidence of endophthalmitis after intravitreal injection with and without topical antibiotic prophylaxis.
Methods: This is a single-center, retrospective case-control study. All patients treated with intravitreal injection of ranibizumab, bevacizumab, aflibercept, or corticosteroids for a variety of retinal vascular diseases between 1 October 2014 and 30 November 2018 were included. The total number of patients and injections were determined from a review of billing code and practice management records. Endophthalmitis cases were determined from billing records and then confirmed with chart review. A 24-month period when topical antibiotics were prescribed after intravitreal injection was compared with a 24-month period when topical antibiotics were not prescribed.
Results: Between 1 October 2014 and 30 November 2018, a total of 33,515 intravitreal injections were performed and 13 cases of post-intravitreal injection endophthalmitis were identified (incidence rate of 0.0388%; 95% confidence interval, 0.0217%-0.0644%) or approximately 1 case for every 2578 intravitreal injections. Between 1 October 2014 and 31 October 2016, while topical antibiotic prophylaxis was used postoperatively, 14,828 intravitreal injections were performed and 5 cases of endophthalmitis were reported (0.0337%; 95% confidence interval, 0.0129%-0.0739%). Between 1 November 2016 and 30 November 2018, while no prophylaxis was used, 18,687 intravitreal injections were performed and 8 cases of endophthalmitis were identified (0.0428%; 95% confidence interval, 0.0202%-0.0808%). There were no statistical differences in the incidence rates between the two groups (p = 0.675).
Conclusion: The incidence rate of endophthalmitis in the group with topical antibiotic prophylaxis after intravitreal injection was similar to the group with no prophylaxis. Changing the current clinical practice to no antibiotic prophylaxis had no effect on the incidence of endophthalmitis.
Keywords: Antibiotic prophylaxis; anti–vascular endothelial growth factor; corticosteroids; diabetic macular edema; endophthalmitis; intravitreal injection; neovascular age-related macular degeneration.