All three anti-VEGF agents currently being used have a low incidence of post-injection inflammation, ranging between 0.02% and 0.16%. However, there have been reports of sporadic spurts of increased incidents of sterile inflammation following aflibercept injection. While these incidents could be related to certain batches of the drug, the authors propose other possible causes that are thought provoking.
They found that, one, all aflibercept-injected eyes with inflammation had silicone oil droplets in the vitreous cavity and were injected with Saldanha Rodrigues syringes, which are more likely to release silicone oil droplets during injection, and, two, intense agitation of samples in the syringes form large protein aggregates, upon biophysical analyses, which may contribute to development of inflammation. They cite other studies that found association between silicone oil-water interfaces (siliconized syringe walls), air-water interfaces (air bubbles) and agitation stress (flicking of syringes at the time of injection) as triggers leading to protein aggregation and particle formation. In addition, a fusion protein, compared with monoclonal antibody, may be more prone to yield insoluble aggregates. Because aflibercept is a fusion protein, they suggest that it may be more prone to aggregation. Based on their findings, we should not “flick” the syringe too aggressively as we try to remove the air bubbles out after drawing up the drugs, especially aflibercept, and try to use silicone-free syringes, when possible, to minimize post-injection inflammation.
Judy E. Kim, MD
OSN Retina/Vitreous Board Member
Disclosures: Kim reports she is on the advisory board of or is a consultant to Allergan, Alimera, Clearside, EyePoint, Genentech and Kodiak.