Title

TO ANALYZE THE DEAD SPACE SYRINGE FOR INTRA-VITREOUS INJECTIONS

Introduction

The introduction of antibody-based biologics targeting of the vascular endothelial growth factor (VEGF) to treat retinal diseases changed the approach for maculopathies. The injections are highly effective and have markedly decreased the risk of visual impairment. Since this kind of diseases are chronic in their nature, and most patients need long-term therapy to suppress disease activity the necessity to reduce the waste has to be considered. Many countries developed methods to compound in multiples doses the anti-VEGF without compromising drug stability or activity. In this study, we describe a novel method to quantify the waste volume left into the plastic syringe after anti-VEGF injection and elected the best plastic syringe to use during intra-vitreous injections.

Methods

Eight different models of plastic syringes were evaluated to analyze the residual volume after injections. Each syringe model was divided in groups with 10 samples and each sample was measure the weight using a caliper: before fill the volume, after fill the volume of 0.05ml and after the injection. We compare results to evaluate the syringe with low residual waste volume.

Results

The means residual volume of the group were between 0.002g to 0.032g. The syringe without needle had the higher weight with a statistic significant results comparing with all the syringes with permanent needle. The were no statistic significant residual volume in all syringes with permanent needle.

Discussion

A syringe to minimal drug waste for intra-vitreous injection of anti-VEGF is necessary to reduce the treatment cost of the patients because the number of the injections per year is high. Our study showed if we use a syringe without needle a residual volume of 58 per cent of the total amount injected remains in dead space, which means a despise of one dose treatment (0.05ml) for each two injections. In conclusion, the authors suggests use syringe with permanent needle to reduce significantly the waste volume.

Keywords

Permanet needle Syringe, intra-vitreous injection, retinopathy, anti-VEGF, diabetic edema, macula edema

Area

SURGICAL CASE

Authors

Anderson Teixeira, Isadora Rosa Francisco Silva, Amelia de Oliveira Pereira, Camila Salaroli