Ophthalmol Retina. 2023 Jun 9:S2468-6530(23)00254-3. doi: 10.1016/j.oret.2023.06.003. Online ahead of print.
ABSTRACT
PURPOSE: To compare accuracy, precision, and residual volume of commonly used syringes for intravitreal injections (IVI), and to assess the intraocular pressure (IOP) rise by variations in volumes delivered.
DESIGN: Experimental lab study.
SUBJECTS: No subjects were involved in this study.
METHODS: We tested 8 syringe models with 2 different needle setups, with 2 different solutions (distilled water or glycerin) and target volumes (50 and 70 μL). To obtain the delivered and residual volumes, we weighed the syringe-needle setups with scale before liquid withdrawal, with liquid, and after liquid release. We also created an experimental eye model to determine the transient rise in IOP following stepwise 10-μL increases in injection volumes.
MAIN OUTCOME MEASURES: Delivered and residual volumes, IOP rise.
RESULTS: We tested a total of 600 syringe-needle setups. BD Ultra-Fine (0.34 ± 0.28 μL), Zero Residual (1.53 ± 1.15 μL) and Zero Residual Silicone Oil-free (1.40 ± 1.16 μL) syringes showed the lowest residual volume (p<0.001) in comparison to the others (range: 24.86 ± 1.78 μL for Injekt-F to 51.97 ± 3.37 μL for Omnifix-F). The most accurate setups were (percentage deviation from target volume): Zero Residual Silicone Oil-free (+0.70%), Zero Residual 0.3 mL (+4.49%), BD Ultra-Fine (+7.83%), Injekt-F (9.42%), Norm-Ject (+15.88%), Omnifix-F (+16.96%), BD Plastipak Brazil (+17.96%), and BD Plastipak Spain syringes (+19.41%). There was a statistically significant difference between the Zero Residual Silicone Oil-free syringe and all other syringes (p<0.0001), except for the Zero Residual 0.3 mL syringe (p=0.029). The coefficient of variation was low for all syringes. The modeled IOP rise ranged from 32.3 (SD 1.4) mmHg for 20-μL injection volume to 76.5 (SD 1.0) mmHg for 80-μL injection volume. For the standard 50-μL injection volume, the peak pressure was 50.7 (SD 0.1) mmHg, and the pressure rise duration was 28 (SD 2) minutes.
CONCLUSIONS: There were significant differences in accuracy and residual volume between syringes, whereas they showed a high precision. Volume excess results in a considerable increase in IOP rise following injection. These findings may provide a relevant overview to clinicians and to both device and drug manufacturers regarding pharmacoeconomic, safety and efficacy issues.
PMID:37302655 | DOI:10.1016/j.oret.2023.06.003
