title: Analgesic effect of supplemental intracameral lidocaine during phacoemulsification under topical anaesthesia: a randomised controlled trial.
abstract: OBJECTIVE
  To determine the analgesic effect of supplemental intracameral lidocaine 1% during phacoemulsification under topical anaesthesia, and to assess the risk factors associated with pain.
  
  
  METHODS
  In a double-masked, randomised, clinical trial, 506 patients undergoing phacoemulsification under topical anaesthesia were randomised to receive a supplemental intracameral injection of either 0.5 cc of 1% lidocaine (277 patients, 54.7%) or balanced salt solution (BSS) (229 patients, 45.3%). Patients were interviewed by a trained interviewer using a standardised questionnaire. The main outcome measure was intraoperative pain, scored on a visual analogue scale of 0-10. Logistic regression was performed to assess ORs.
  
  
  RESULTS
  125 of 277 patients (45.1%) experienced pain in the lidocaine group, compared with 123 of 229 patients (53.7%) in the BSS group. The proportion of patients who experienced pain was significantly lower in the intracameral lidocaine group compared with the BSS group (multivariate OR 0.68, 95% CI 0.47 to 0.97; p=0.034). The median pain score (range) was 0.0 for intracameral lidocaine group compared with 1.0 for BSS group (p=0.039). Pain was more common in females (54.3% vs 43.6%; OR 1.56), non-Chinese (62.3% vs 46.9%; OR 2.13) and those who had previous cataract surgery to the fellow eye (55.3% vs 44.7%; OR 1.61).
  
  
  CONCLUSIONS
  The use of 0.5 cc of 1% intracameral lidocaine during phacoemulsification under topical anaesthesia significantly reduces pain experienced by patients. Risk factors for pain include females, non-Chinese and previous cataract surgery.
authors.affiliation: Department of Opthalmology, Tan Tock Seng Hospital, Singapore, Singapore. colintan_eye@yahoo.com.sg
authors.forename: Colin S H
authors.initials: CS
authors.lastname: Tan
authors.forename: Han-Bor
authors.initials: HB
authors.lastname: Fam
authors.forename: Wee-Jin
authors.initials: WJ
authors.lastname: Heng
authors.forename: Hung-Ming
authors.initials: HM
authors.lastname: Lee
authors.forename: Seang-Mei
authors.initials: SM
authors.lastname: Saw
authors.forename: Kah-Guan
authors.initials: KG
authors.lastname: Au Eong
mesh_terms: D000368:Aged; D000772:Anesthesia, Local / Q000379:methods; D019162:Anesthetics, Combined / Q000008:administration & dosage; D000779:Anesthetics, Local / Q000008:administration & dosage*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007431:Intraoperative Complications / Q000188:drug therapy* / Q000523:psychology; D008012:Lidocaine / Q000008:administration & dosage*; D008297:Male; D010146:Pain / Q000188:drug therapy* / Q000523:psychology; D010147:Pain Measurement; D017060:Patient Satisfaction; D018918:Phacoemulsification / Q000009:adverse effects / Q000379:methods* / Q000523:psychology; D012846:Singapore; D011795:Surveys and Questionnaires; D016896:Treatment Outcome
chemical_list: D019162:Anesthetics, Combined; D000779:Anesthetics, Local; D008012:Lidocaine