Agitation of the syringe and release of silicone oil

Background/objectives To investigate whether agitation promotes the release of silicone oil by different models of syringe used for intravitreal injection. Methods This lab study analyzed eight syringe models by light microscopy for the release of silicone oil under agitation (flick), without agitation, and positive controls. Fourier-Transform Infrared Spectroscopy (FTIR) was performed to identify the molecular compounds inside the syringes. Results A total of 240 syringes were analyzed. The presence of silicone oil droplets was observed in all positive controls. When agitated by flicking, 100% of the samples of the syringes disclosed silicone oil, except the BD Plastipak syringe, which presented 40% of positivity. Without agitation, a smaller percentage of samples with silicone oil was observed. Agitation by flicking had a 265-fold greater chance of presenting oil droplets when compared with the syringes without agitation. There was a statistically significant difference between the three conditions ( P