Abstract
Purpose: :
To assess pain perception between topical, sub-Tenon’s and peribulbar anaesthesia for phacoemulsification surgery using the short form McGill Pain Questionnaire (SF-MPQ). The SF-MPQ is a validated, accepted instrument which assesses sensory and affective components of pain, present pain intensity(PPI) and a visual analogue scale (VAS).
Methods: :
303 patients undergoing their first cataract surgery by phacoemulsification were randomised to receive either topical oxybuprocaine 0.4% drops (100 patients) or injected peribulbar 2% lidocaine with 1 in 200000 epinephrine plus bupivocaine 0.75% (98 patients) or injected sub-Tenon’s lidocaine 2% with 1 in 200000 epinephrine plus bupivocaine 0.75% (105 patients). Phacoemulsification was performed by the same surgeon throughout. Patients scored the severity of the components of their pain by verbal responses to the SF-MPQ, administered by a masked investigator at two separate time points, immediately following anaesthetic administration and immediately post-operatively. Total pain score was defined as the sum of the sensory score and affective score, yielding a total of 0 to 45. The present pain intensity (0-5) and VAS scale (0-10) were reported separately. Pain scores were compared between groups.
Results: :
For anaesthetic administration alone, total pain scores were similar between peribulbar and sub-Tenon’s anaesthetic (mean 2.6 + 3.3 vs 2.1 + 2.9, p= 0.08) but both were higher than with topical drops (1.0 + 0.9, p<0.001 and 0.03). For the surgical procedure, total pain scores were similar between peribulbar and sub-Tenon’s anaesthetic (mean 0.4 + 1.5 vs 0.2 + 0.6, p= 0.6), but both lower than with topical drops (1.5 + 3.6, p=0.0005 and p<0.0001).The present pain intensity score (0-5) was not sensitive enough to detect a difference between anaesthetic methods for either administration of anaesthetic or the surgical procedure (p=0.09 and 0.2). The VAS confirmed more pain during surgery with topical anaesthetic than with peribulbar. (0.32 + 1.03 vs 0.03 + 0.17, p=0.003).
Conclusions: :
Administration of anaesthetic by injection, via peribulbar and sub-Tenon’s routes, prior to phacoemulsification is more uncomfortable for the patient than topical drops. Nevertheless, for the surgical procedure, peribulbar and sub-Tenon’s anaesthetic yield significantly greater intraoperative comfort. Anaesthetic options should be discussed with the patient before surgery to allow an informed patient choice.
Clinical Trial: :
www.ISRCTN.org ISRCTN19439616
Keywords: small incision cataract surgery • clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials • cataract