Prefilled ranibizumab syringes reduce risk of endophthalmitis

This multicenter retrospective study compared the rate of endophthalmitis between prefilled syringes and conventional preparation of ranibizumab.

Study design

This study included 43,132 patients from the United States and Japan. Treated eyes received intravitreal injections of 0.5 mg ranibizumab (165,347 conventional and 78,407 prefilled) for retinal vascular diseases. Researchers identified endophthalmitis cases using billing records and evaluated charts.

Outcomes

Among the patients receiving conventional ranibizumab injections, there were 43 cases of suspected endophthalmitis (0.026%) and 22 cases of culture-positive endophthalmitis (0.013%). In the prefilled ranibizumab group, there were 12 cases of suspected endophthalmitis (0.015%) and 2 cases of culture-positive endophthalmitis (0.0026%). Prefilled syringes correlated with a reduced risk of suspected endophthalmitis and a significant decrease in culture-positive endophthalmitis (OR 0.59 and 0.19, respectively).

Eyes that developed endophthalmitis from conventional injections had significantly worse vision loss compared with eyes treated with prefilled syringes (4.45 vs. 0.38 lines lost; P=0.0062).

Limitations

Limitations of this study are related to its retrospective study design. The number of injections with prefilled syringes was less than half the number of injections in the conventional preparation and this imbalance may have affected the study outcomes. The study lacked a standardized protocol for intravitreal injections across institutions.

Clinical significance

Endophthalmitis is a rare but worrisome complication of intravitreal injections. The preparation of the injection in the office—such as drawing medication from the vial—is fraught with chances for contamination. Prefilled syringes eliminate this risk and, as this study shows, might be valuable in decreasing the risk of endophthalmitis.