title: Injection force comparison of the old and new dexamethasone implant insertion needles in porcine eyes and synthetic sclera.
abstract: 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.
  
  
  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.
  
  
  CONCLUSIONS
  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.
authors.forename: Alexander M
authors.initials: AM
authors.lastname: Eaton
authors.forename: Gabriel M
authors.initials: GM
authors.lastname: Gordon
authors.forename: Dave
authors.initials: D
authors.lastname: Booth
authors.forename: Hussein
authors.initials: H
authors.lastname: Wafapoor
authors.forename: Robert L
authors.initials: RL
authors.lastname: Avery
mesh_terms: D000818:Animals; D003907:Dexamethasone / Q000008:administration & dosage*; D004343:Drug Implants; D004867:Equipment Design; D005938:Glucocorticoids / Q000008:administration & dosage*; D058449:Intravitreal Injections / Q000295:instrumentation*; D008422:Materials Testing; D055595:Mechanical Phenomena; D009339:Needles; D011312:Pressure; D012590:Sclera; D017768:Skin, Artificial; D013552:Swine; D014822:Vitreous Body / Q000187:drug effects*
chemical_list: D004343:Drug Implants; D005938:Glucocorticoids; D003907:Dexamethasone