Silicone Oil Migration During Intravitreal Anti-VEGF Injections: A Review of Clinical Evidence and Factors Related to...

To evaluate the incidence, mechanisms, and clinical implications of silicone oil (SO) droplet transmission during intravitreal anti-vascular endothelial growth factor (VEGF) injections (IVIs) and to review strategies to mitigate contamination risks.

A systematic review of observational and review studies from PubMed and MEDLINE was conducted, focusing on incidence, contributing factors, and clinical outcomes of SO contamination during IVIs. Specific attention was given to syringe design, storage conditions, variations among anti-VEGF agents, and injection techniques.

The review found that prevalence is high in chronically injected eyes, though per-injection rates are low, often clustering due to syringe batches or techniques. Contributing factors include freeze-thaw cycles, mechanical agitation, spray-siliconized low-dead-space syringes, and improper plunger handling, which can lead to asymptomatic droplets or symptomatic floaters. No severe complications like endophthalmitis were reported. Hypotheses link SO to ocular hypertension or inflammation via trabecular obstruction or immunogenic responses, but the reviewed studies show no direct evidence. Mitigation involves the use of silicone-free/prefilled syringes, strict storage, gentle handling, and refined techniques such as priming and smooth plunger depression.

SO contamination during IVIs can be minimized through careful optimization of syringe design, handling practices, and injection techniques. Embracing silicone-free or low-silicone syringe systems, alongside meticulous procedural protocols, offers the potential to enhance the safety and clinical outcomes of intravitreal anti-VEGF therapy.