Purchase this article with an account.
Alexander M Eaton, Gabriel M Gordon, Dave Booth, Hussein Wafapoor, Robert L Avery, Dyson Hickingbotham; In Vivo and In vitro Force Testing of a New Guarded Injection Device. Invest. Ophthalmol. Vis. Sci. 2015;56(7 ):393.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
A novel guarded injection device (GID) designed to reduce the incidence of contamination during an intravitreal injection (IVI) was recently shown to reduce the time needed for an IVI with a trend towards making injections more comfortable. This GID has been redesigned by a major needle manufacturer for more efficient mass production. We hypothesize that insertion of the 30G GID will not require more work than insertion of a standard 30G needle.
The total work in Newtons (N) for ten 30G GID needles was compared to that of ten standard 30G needles in freshly explanted porcine eyes as well as nine of each in synthetic test media similar to the human sclera. Cross head speeds for the test set were kept constant at 100 microns per second to provide good needle tip and cutting edge force resolution and a force profile with 1000 data points was generated for analysis. Work was compared after insertion to 25 and 50% of the total needle length.
There was no statistically significance difference in the total work after insertion of 25% of the total GID needle length compared to 25% of a standard 30G needle in both the synthetic test media (137.48 N vs 149.93 N, p=0.74) and the porcine eyes (26.50 N vs 35.15 N, p=0.10). There was a statistically significance difference in the total work after insertion of 50% of the GID needle length compared to 50% of a standard 30G needle in both the synthetic test media (273.69 N vs 196.08 N, p<0.001) and the porcine eyes (216.63 N vs 176.93 N, p=0.04).
Insertion of the needle of the new 30G GID does not require significant additional work than a standard 30G needle during insertion of 25% of its length and minimal additional work at insertions of 50% of its length. Understanding the mechanical forces surrounding the use of the GID should help physicians optimize use of the device.
This PDF is available to Subscribers Only