title: Effect of the Honan intraocular pressure reducer in sub-Tenon's anesthesia.
abstract: OBJECTIVE
  To ascertain whether the Honan intraocular pressure reducer (HIPR) has an effect on the preoperative intraocular pressure (IOP), surgeon's assessment of anesthesia, and patients' analgesic experience when sub-Tenon's anesthesia is used for routine cataract surgery.
  
  
  METHODS
  Princess Alexandra Eye Pavilion, Edinburgh, Scotland.
  
  
  METHODS
  Forty-five eyes of 45 patients having routine phacoemulsification cataract surgery were randomized to receive 10 minutes of ocular compression using the HIPR or no compression after administration of sub-Tenon's anesthesia. The IOP was measured immediately before and immediately and 10 minutes after sub-Tenon's anesthesia administration using a standard technique. One surgeon who was masked to the randomization process performed all injections and completed a questionnaire on aspects of the anesthetic block. Patients scored their level of analgesia during surgery.
  
  
  RESULTS
  The mean rise in IOP immediately after administration of sub-Tenon's anesthesia was 1.39 mm Hg +/- 3.91 (SD) (95% confidence interval +0.22 to 2.57; P =.021). In the 22 patients who received compression, there was a mean IOP reduction of 4.20 +/- 2.74 mm Hg at 10 minutes. The mean difference between the compression and no-compression groups at 10 minutes was 4.99 mm Hg (P<.0001). There was no difference in the surgeon's scores for any aspect of the sub-Tenon's anesthesia (P>.05). All patients reported good levels of analgesia.
  
  
  CONCLUSIONS
  There was a significant reduction in IOP after compression using the HIPR. However, the rise in IOP after administration of sub-Tenon's anesthesia was small and the use of the HIPR did not make a significant difference in the effectiveness of the anesthesia to the surgeon or patients.
authors.affiliation: Princess Alexandra Eye Pavilion, Edinburgh, Scotland, United Kingdom. jimvallance@hotmail.com
authors.forename: James H
authors.initials: JH
authors.lastname: Vallance
authors.forename: Niall
authors.initials: N
authors.lastname: Patton
authors.forename: Andrew
authors.initials: A
authors.lastname: Ferguson
authors.forename: Harry G
authors.initials: HG
authors.lastname: Bennett
mesh_terms: D000368:Aged; D000772:Anesthesia, Local / Q000379:methods*; D019162:Anesthetics, Combined / Q000008:administration & dosage; D000779:Anesthetics, Local / Q000008:administration & dosage*; D002045:Bupivacaine / Q000008:administration & dosage; D002404:Catheterization; D003238:Connective Tissue; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007429:Intraocular Pressure; D008012:Lidocaine / Q000008:administration & dosage; D008297:Male; D008365:Manometry; D009798:Ocular Hypertension / Q000517:prevention & control*; D018918:Phacoemulsification / Q000379:methods
chemical_list: D019162:Anesthetics, Combined; D000779:Anesthetics, Local; D008012:Lidocaine; D002045:Bupivacaine