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.