Abstract
Purpose: :
To determine whether 0.3 cc syringes deliver more accurate and precise intraocular volumes than conventional 1.0 cc syringes.
Methods: :
Injections of distilled water were performed into enucleated human eyes using 0.3 cc (BD, Franklin Lakes, NJ) and 1.0 cc syringes (BD Franklin Lakes, NJ) with an intended volume of 50 µL. For each syringe type, 10 syringes were tested with 6 injections each. The eye was weighed on an analytic balance prior to and after each intraocular injection. Volume of injection was inferred from the change in mass, assuming a density of water of 1.0g/cc. The accuracy of injection volume for each syringe type was evaluated using a 1 sample t-test. Volumes of injection of the 0.3 cc and 1 cc syringes were compared using the unpaired t-test. Variance of distribution (precision) of the two syringe types was compared using the F-test.
Results: :
The mean volume delivered with 60 injections each with the 0.3 cc and 1.0 cc syringes was 49.86 µL (S.D.= 1.29) and 50.79 µL (S.D = 4.21), respectively (p=0.11). No significant difference between delivered and intended volume was seen for either type of syringes (p>0.28). Actual volume delivered by 1.7% of 0.3 cc syringe injections and 18.3% of 1.0 cc syringe injections had a difference of 10% or greater than intended volume delivered. The variance (precision) was superior for the 0.3cc syringe (p<<0.001).
Conclusions: :
Under ideal laboratory conditions, both syringes offer good accuracy. However, the 0.3 cc syringes are significantly more precise in delivering 50 µL injections than 1.0 cc syringes.