Abstract
Introduction: :
Prospective Trial of Botulinum Toxin (Botox®) to Control Post-Operative Pain in Eye Enucleation and Evisceration Surgeries
Purpose: :
To investigate the analgesic efficacy of Botox® (botulinum toxin type A) in controlling post-operative pain following eye enucleation and evisceration surgeries.
Methods: :
Adult patients scheduled for first-time enucleation or evisceration surgery were recruited over a two-year period and randomized in a double-blinded fashion to receive Botox or saline (placebo) injections at the time of surgery. The four recti muscles once exposed were injected with either 5 units of 0.1 mL Botox or an equivalent volume of saline as placebo. A standardized post-operative analgesic/narcotic regimen was given as needed.A 10-point numerical ranking scale was used to measure patients’ subjective experiences of pain and nausea, with 0 being no pain/nausea and 10 being the "worst [pain/nausea] imaginable." Pain and nausea were measured pre-operatively, 2-3 hours from the block time in the recovery room; 8-9 hours from the block time, then daily for one week, weekly for one month and bi-weekly for two months for a total of three months' study time.
Results: :
Patients who received Botox injection at the time of surgery, as compared to placebo, reported significantly decreased pain levels intraoperatively (mean pain level of 0.27 in treatment group compared to 1.7 in placebo group.) This effect was observed at 8-9 hours from the time of the block. Thereafter, pain scale ratings were similar from POD 1-Week 2 among the two groups. In both groups, there was no reported pain after Week 3. The post-operative narcotic requirement was roughly halved in the treatment group. Antiemetic requirement was reduced by 30% in the treatment arm. In addition, all patients in the placebo group were admitted post-operatively, whereas 3/14 patients in the treatment group were discharged home on the day of surgery.
Conclusions: :
Patients who received intramuscular injections of Botox as compared to placebo reported significantly decreased pain levels intraoperatively lasting until 8-9 hours from the time of the block. Post-operative narcotic requirement was decreased by 50% in the treatment arm, and antiemetic requirement was decreased by 30%. Intraoperative use of Botox may offer a great potential for post-operative analgesia and possibly reduce or eliminate post-operative drug regimen and length of hospital stay.
Clinical Trial: :
www.eyesite.ca/ 1715-3360
Keywords: wound healing • drug toxicity/drug effects