Prospective Study of Silicone Oil Microdroplets in Eyes Receiving Intravitreal Anti-Vascular Endothelial Growth Factor Therapy in 3 Different Syringes.

PURPOSE: To compare the prevalence of intravitreal silicone oil microdroplets detected by slit-lamp biomicroscopy in eyes with 6 or more injections of the same anti-vascular endothelial growth factor (VEGF) drug. DESIGN: Prospective, cross-sectional case series. PARTICIPANTS: A total of 260 consecutive eyes receiving 1 of 3 intravitreal anti-VEGF drugs for choroidal neovascularization, diabetic macular edema, or venous occlusive disease. The control group included 147 fellow eyes with no prior intravitreal injections. METHODS: The anterior and mid-vitreous were carefully examined using 12× to 16× magnification through dilated pupils with ocular saccades before an injection. Silicone oil microdroplets were graded on a scale from 0 to 4+ based on the number and size of droplets. MAIN OUTCOME MEASURES: Presence and severity of silicone oil microdroplets in the vitreous. RESULTS: Silicone oil microdroplets were observed in 78.3% of eyes receiving bevacizumab in Becton Dickinson (BD, Franklin Lakes, NJ) 0.3-mL polypropylene syringes, 14.4% of eyes receiving ranibizumab in 1.0-mL BD polypropylene syringes or more recently glass prefilled syringes, 48.5% of eyes receiving aflibercept in 1.0-mL BD polycarbonate syringes, and 0% of eyes in controls. The differences among the 4 groups were statistically significant at P < 0.001. The severity of silicone oil microdroplets was significantly greater in eyes using BD 0.3-mL polypropylene syringes than BD 1.0-mL polypropylene syringes, BD 1.0-mL polycarbonate syringes, or controls (P < 0.001). The severity of silicone oil microdroplets in eyes using BD 1.0-mL polycarbonate syringes was significantly greater than BD 1.0-mL polypropylene syringes (P = 0.012) and controls (P < 0.001). There was no significant difference between silicone oil microdroplet severity between BD 1.0-mL polypropylene syringes and controls (P = 1.0). CONCLUSIONS: The BD 0.3-mL polypropylene syringes with repackaged bevacizumab and the BD 1.0-mL polycarbonate syringes with aflibercept cause a higher likelihood of silicone oil microdroplets. Intravitreal injections in eyes receiving multiple regular anti-VEGF injections should be supplied in silicone-free syringes.