title: Local Anesthesia With Blunt Sub-Tenon's Cannula Versus Sharp Retrobulbar Needle for Vitreoretinal Surgery: A Retrospective, Comparative Study.
abstract: OBJECTIVE
  To evaluate the safety and efficacy of a blunt sub-Tenon's cannula for local anesthesia before vitreoretinal surgery compared to a sharp retrobulbar needle.
  
  
  METHODS
  Retrospective, comparative study of all patients undergoing vitreoretinal surgery at the Medical College of Wisconsin between August 2009 and November 2013. Institutional review board approval was obtained.
  
  
  RESULTS
  Of 940 surgeries performed with a sub-Tenon's cannula, 99% (938 of 940) were completed. Of the 771 surgeries performed with a sharp retrobulbar needle, 99% (770 of 771) were completed. Factors associated with use of a sharp retrobulbar needle over sub-Tenon's cannula were presence of prior scleral buckle (P < .01) and inclusion of scleral buckle placement in the procedure (P < .01). No case of globe perforation, severe retrobulbar hemorrhage, or severe conjunctival chemosis was observed in either group.
  
  
  CONCLUSIONS
  Blunt sub-Tenon's cannula appears as effective and safe as a sharp retrobulbar needle for local anesthesia during vitreoretinal surgery. Vitreoretinal surgeons may wish to consider a blunt sub-Tenon's cannula for local surgical anesthesia.
authors.forename: David A
authors.initials: DA
authors.lastname: Reichstein
authors.forename: Clinton C
authors.initials: CC
authors.lastname: Warren
authors.forename: Dennis P
authors.initials: DP
authors.lastname: Han
authors.forename: William J
authors.initials: WJ
authors.lastname: Wirostko
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000772:Anesthesia, Local / Q000295:instrumentation* / Q000379:methods; D000779:Anesthetics, Local / Q000008:administration & dosage*; D057785:Catheters; D005260:Female; D006801:Humans; D008012:Lidocaine / Q000008:administration & dosage; D008297:Male; D008875:Middle Aged; D009339:Needles; D012189:Retrospective Studies; D058475:Tenon Capsule / Q000187:drug effects; D057586:Vitreoretinal Surgery; D055815:Young Adult
chemical_list: D000779:Anesthetics, Local; D008012:Lidocaine