Endophthalmitis Rates of Ranibizumab in Pre-Filled Syringes Compared to Vials

Abstract

Purpose : Pre-filled syringes are emerging as an alternative to the vial-and-syringe method used for administration of intravitreal biologics. By eliminating several steps in the administration of intravitreal injections, pre-filled syringes hold the potential to decrease risk of infectious endophthalmitis. We tested the hypothesis that injections performed with a pre-filled 0.5 mg ranibizumab syringe may result in decreased rates of acute bacterial endophthalmitis compared to injections performed with the single-use vial 0.5 mg ranibizumab.

Methods : We conducted a multicenter retrospective cohort study of intravitreal injections with pre-filled syringe and single-vial formulations of 0.5 mg ranibizumab performed from January 1, 2016 to November 1, 2017 at 6 retina practices in the United States, and from June 1, 2009 to July 30, 2017 at 2 retina practices in Japan. Billing records and endophthalmitis logs were used to identify the total number of injections as well as patients who developed endophthalmitis following injection. Chart reviews were subsequently performed for these patients to confirm that the endophthalmitis diagnosis was linked to the preceding ranibizumab injection. The primary outcome of the study was to compare the incidence of post-injection endophthalmitis between pre-filled and single-vial ranibizumab. A two-tailed z-score test was used to determine if there was a significant difference in endophthalmitis rates. Odds ratios were also calculated to compare the odds of developing endophthalmitis from the two formulations.

Results : A total of 186,393 ranibizumab injections were performed: 54,585 using pre-filled syringes, and 131,808 using vials. We identified 54 cases of endophthalmitis in the total cohort (0.03% [1 in 3,452]). The rate of endophthalmitis for pre-filled ranibizumab was 0.02% (12/54,585 [1 in 4,549]), compared to 0.03% (42/131,808 [1 in 3,138]; p = 0.254) after ranibizumab in vials. The odds ratio for developing endophthalmitis following vial versus pre-filled ranibizumab was 1.45 (95% CI: 0.76 to 2.75; p = 0.257).

Conclusions : The rate of endophthalmitis following intravitreal ranibizumab injection was low, and the difference between pre-filled syringes versus vials was not statistically significant.

This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.