The Impact of Prefilled Syringes on Endophthalmitis Following Intravitreal Injection of Ranibizumab

Purpose: To compare the rates of infectious endophthalmitis following intravitreal injection of ranibizumab using prefilled syringes vs conventional preparation. Design: Multicenter retrospective cohort study. Methods: All eyes receiving intravitreal injection of 0.5 mg ranibizumab for retinal vascular diseases at 10 retina practices across the United States (2016 to 2017) and Japan (2009 to 2017) were included. The total numbers of eyes and injections were determined from billing codes. Endophthalmitis cases were determined from billing records and evaluated with chart review. Primary outcome was the rate of postinjection acute endophthalmitis. Secondary outcomes were visual acuity and microbial spectrum. Results: A total of 243 754 intravitreal 0.5 mg ranibizumab injections (165 347 conventional and 78 407 prefilled) were administered to 43 132 unique patients during the study period. In the conventional ranibizumab group, a total of 43 cases of suspected endophthalmitis occurred (0.026%; 1 in 3845 injections) and 22 cases of culture-positive endophthalmitis occurred (0.013%; 1 in 7516 injections). In the prefilled ranibizumab group, 12 cases of suspected endophthalmitis occurred (0.015%; 1 in 6534 injections) and 2 cases of culture-positive endophthalmitis occurred (0.0026%; 1 in 39 204 injections). Prefilled syringes were associated with a trend toward decreased risk of suspected endophthalmitis (odds ratio 0.59; 95% confidence interval 0.31-1.12; P =.10) and a statistically significant decreased risk of culture-positive endophthalmitis (odds ratio 0.19; 95% confidence interval 0.045-0.82; P =.025). Average logMAR vision loss at final follow-up was significantly worse for eyes that developed endophthalmitis from the conventional ranibizumab preparation compared to the prefilled syringe group (4.45 lines lost from baseline acuity vs 0.38 lines lost; P =.0062). Oral-associated flora was found in 27.3% (6/22) of conventional ranibizumab culture-positive endophthalmitis cases (3 cases of Streptococcus viridans, 3 cases of Enterococcus faecalis) compared to 0 cases in the prefilled ranibizumab group. Conclusion: In a large, multicenter, retrospective study the use of prefilled syringes during intravitreal injection of ranibizumab was associated with a reduced rate of culture-positive endophthalmitis, including from oral flora, as well as with improved visual acuity outcomes.