title: Comparison of the tissue penetration and glide force of 22-gauge thin-wall needles for intravitreal implant administration.
abstract: OBJECTIVE
  To identify a needle to improve intravitreal dexamethasone implant administration by evaluating ease of ocular tissue penetration and glide force, key characteristics of needle performance.
  
  
  METHODS
  Two custom-applicator needles coated with distinct lubricants (needles A and B) and the original dexamethasone implant needle were evaluated by five retina specialists. Ex vivo porcine eyes were injected, and a visual analog scale was used in ratings.
  
  
  RESULTS
  Ease of ocular tissue penetration and glide force of needle B were rated significantly higher than that of the original applicator needle (P < .001), but there were no significant differences for needle A. Lot to lot, needle B was not significantly different in penetration and glide, whereas a significant difference was observed for penetration of needle A (P = .043).
  
  
  CONCLUSIONS
  Needle design and lubricant appear to facilitate penetration and reduce glide force when administering dexamethasone intravitreal implants. Minimal lot-to-lot variation should be considered in needle choice.
authors.affiliation: Mayo Clinic, Rochester, MN 55905, USA. bakri.sophie@mayo.edu
authors.forename: Sophie J
authors.initials: SJ
authors.lastname: Bakri
authors.forename: David S
authors.initials: DS
authors.lastname: Boyer
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Albini
authors.forename: Nancy M
authors.initials: NM
authors.lastname: Holekamp
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Ferrone
authors.forename: Rahul
authors.initials: R
authors.lastname: Bhagat
authors.forename: Zoran
authors.initials: Z
authors.lastname: Novakovic
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; D009339:Needles; D019919:Prosthesis Implantation / Q000295:instrumentation*; D013552:Swine; D014605:Uveitis / Q000188:drug therapy*
chemical_list: D004343:Drug Implants; D005938:Glucocorticoids; D003907:Dexamethasone