title: Comparison of 20-, 23-, and 25-gauge air infusion forces.
abstract: OBJECTIVE
  To determine and compare 20-, 23-, and 25-gauge retinal infusion air jet impact pressure (force per unit area) in an experimental setting.
  
  
  METHODS
  Experimental laboratory investigation. Infusion cannulas were connected to a compressed air system. A controlled valve mechanism was used to obtain increasing levels of infusion pressure. Each infusion tube was positioned in front of a manual transducer to measure force. Impact pressure was calculated using known formulas in fluid dynamics.
  
  
  RESULTS
  The 20-gauge infusion jet showed similar impact pressure values compared with the 23-gauge infusion jet. Both showed higher levels than the 25-gauge infusion jet. This was because of the smaller jet force for the 25-gauge system.
  
  
  CONCLUSIONS
  In this experimental study, both the 23- and the 20-gauge air infusion jet showed higher impact pressure values compared with the 25-gauge air infusion jet. This could be of concern regarding air infusion during 23-gauge vitrectomy since retinal damage has been shown in standard-gauge surgeries.
authors.affiliation: Department of Ophthalmology, Federal University of São Paulo, São Paulo, São Paulo, Brazil. leo_m@terra.com.br
authors.forename: Leonardo Martins
authors.initials: LM
authors.lastname: Machado
authors.forename: Octaviano
authors.initials: O
authors.lastname: Magalhães
authors.forename: Mauricio
authors.initials: M
authors.lastname: Maia
authors.forename: Eduardo B
authors.initials: EB
authors.lastname: Rodrigues
authors.forename: Michel Eid
authors.initials: ME
authors.lastname: Farah
authors.forename: Kamal A R
authors.initials: KA
authors.lastname: Ismail
authors.forename: Leandro
authors.initials: L
authors.lastname: Molon
authors.forename: Danilo A
authors.initials: DA
authors.lastname: Oliveira
mesh_terms: D002404:Catheterization / Q000295:instrumentation*; D058868:Compressed Air / Q000009:adverse effects*; D006801:Humans; D057446:Hydrodynamics; D007263:Infusions, Parenteral; D008866:Microsurgery / Q000295:instrumentation*; D008962:Models, Theoretical; D011312:Pressure; D014821:Vitrectomy