title: Local anaesthetic techniques and pulsatile ocular blood flow.
abstract: OBJECTIVE
  To compare pulsatile ocular blood flow (POBF) and intraocular pressure (IOP) between eyes of patients receiving either peribulbar (with and without balloon compression) or subconjunctival local anaesthesia (LA).
  
  
  METHODS
  30 eyes of 30 patients undergoing cataract surgery by phacoemulsification were investigated in a study of parallel group design. Ten patients had peribulbar LA and 10 minutes compression with a Honan's balloon (group A). A further 10 patients who received peribulbar LA alone (group B) acted as controls for the effects of balloon compression. Ten other patients were given subconjunctival LA (group C). POBF and IOP were measured using a modified Langham pneumatonometer. Three measurements were made in each eye, the first recording immediately before LA, the second 1 minute after, and the third 10 minutes after LA.
  
  
  RESULTS
  No significant change in POBF or IOP was recorded in eyes receiving subconjunctival LA. In the peribulbar groups (A and B), there was a drop in median POBF of 252 and 138 microl/min respectively 1 minute after LA, which was statistically significant in both groups (p<0. 01). By 10 minutes, POBF tended to return to baseline levels, but remained significantly reduced in group B (p<0.05). In addition, there was a significant (p<0.05) reduction in IOP (mean drop of 4.82 mm Hg) in group A following peribulbar LA with balloon compression.
  
  
  CONCLUSIONS
  POBF was significantly reduced after peribulbar LA but was unchanged after subconjunctival LA. Balloon compression reduced IOP and improved POBF following peribulbar LA. The findings may have clinical implications in patients with compromised ocular circulation or significant glaucomatous optic neuropathy.
authors.affiliation: West of England Eye Unit, Royal Devon and Exeter Hospital, Exeter, UK.
authors.forename: B Y
authors.initials: BY
authors.lastname: Chang
authors.forename: W C
authors.initials: WC
authors.lastname: Hee
authors.forename: R
authors.initials: R
authors.lastname: Ling
authors.forename: D C
authors.initials: DC
authors.lastname: Broadway
authors.forename: B
authors.initials: B
authors.lastname: Beigi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000772:Anesthesia, Local / Q000379:methods*; D000779:Anesthetics, Local / Q000008:administration & dosage*; D001783:Blood Flow Velocity / Q000187:drug effects* / Q000502:physiology; D002045:Bupivacaine / Q000008:administration & dosage; D005123:Eye / Q000098:blood supply*; D005260:Female; D006801:Humans; D007429:Intraocular Pressure / Q000187:drug effects* / Q000502:physiology; D008012:Lidocaine / Q000008:administration & dosage; D008297:Male; D008875:Middle Aged; D018918:Phacoemulsification; D011446:Prospective Studies; D011673:Pulsatile Flow / Q000187:drug effects; D018709:Statistics, Nonparametric; D013748:Tetracaine / Q000008:administration & dosage
chemical_list: D000779:Anesthetics, Local; D013748:Tetracaine; D008012:Lidocaine; D002045:Bupivacaine