Injection force comparison of the old and new dexamethasone implant insertion needles in porcine eyes and synthetic sclera.

BACKGROUND AND OBJECTIVE

Determine whether the new dexamethasone intravitreal implant (Ozurdex; Allergan, Irvine, CA) injector needle design can reduce the force needed for insertion when compared to the original needle design.

MATERIALS AND METHODS

In vitro testing assessed the force required for insertion from five new-design and five old-design Ozurdex needles on a synthetic test medium and explanted porcine eyes. Maximum penetration force was measured in grams-force, while the total work of the needle was measured in joules.

RESULTS

The new design required 29% and 68% less overall work to perform an injection in the synthetic medium (P = .0002) and porcine eyes (P = .009), respectively. The maximum force required to insert the new needle was 25% and 61% that of the old needle in the synthetic medium (P = .001) and porcine eyes (P = .007), respectively.

CONCLUSION

The new needle design significantly reduces the force and work needed for insertion, which should improve physician control as well as patient safety and comfort.