title: A minimally invasive jet injector for intravitreal and subconjunctival injection.
abstract: OBJECTIVE
  To evaluate a minimally invasive injector for intravitreal and subconjunctival administration of medications.
  
  
  METHODS
  The device has a microneedle that communicates with an internal formulation chamber. A piercing depth-limiting flange restricts microneedle penetration to a depth of less than 1 mm and defines the location of the pars plana from the limbus. The jet injector creates a force of up to 1,000 psi, forcing the medication through the remaining sclera/choroid thickness. The device was tested in 28 enucleated rabbit eyes and 9 experimental and 4 control rabbit eyes to define jet pressure for subconjunctival and intravitreal injection.
  
  
  RESULTS
  Injection pressures of 76 to 156 psi were needed for subconjunctival injection and 974 psi for intravitreal injection. Clinical and histologic examinations did not reveal damage to intraocular structures.
  
  
  CONCLUSIONS
  The semi-automated jet injector facilitated intravitreal/subconjunctival injection. The microneedle-assisted jet injector minimized the risk of wet injection by anchoring the microneedle in the sclera.
authors.affiliation: Department of Basic Medical Sciences, University of Arizona, Phoenix, Arizona, USA. gpeyman1@yahoo.com
authors.forename: Gholam A
authors.initials: GA
authors.lastname: Peyman
authors.forename: Kamran
authors.initials: K
authors.lastname: Hosseini
authors.forename: Michel
authors.initials: M
authors.lastname: Cormier
mesh_terms: D000818:Animals; D003228:Conjunctiva / Q000187:drug effects; D016503:Drug Delivery Systems / Q000295:instrumentation*; D007277:Injections, Jet / Q000295:instrumentation; D058449:Intravitreal Injections / Q000295:instrumentation*; D019060:Minimally Invasive Surgical Procedures / Q000295:instrumentation*; D009883:Ophthalmic Solutions / Q000008:administration & dosage*; D004364:Pharmaceutical Preparations / Q000008:administration & dosage*; D011817:Rabbits; D014822:Vitreous Body / Q000187:drug effects
chemical_list: D009883:Ophthalmic Solutions; D004364:Pharmaceutical Preparations