Topical anaesthesia for phacoemulsification surgery

Although phacoemulsification with only topical anaesthesia is possible, the level of any discomfort perceived by the patient is unknown. Topical anaesthesia eliminates any risk of inadvertent ocular or orbital injury. Twenty-four patients undergoing phacoemulsification under only topical anaesthesia (g. amethocaine 1%) were compared with 23 patients undergoing the same procedure with peribulbar anaesthesia (5 ml lignocaine 2%, 5 ml bupivacaine 0.5% and 75 units hyaluronidase). Perceived pain on administration of the anaesthesia, per-operatively and post-operatively was assessed by a nursing officer using a visual analogue scale (0-10). It was found that there was no difference in pain score between the two groups on induction of anaesthesia. Per-operatively and post-operatively scores were higher in the topical group than in the peribulbar group (p < 0.05, Mann-Whitney U-test), though most of these were within the range 0-3, ('no pain' to 'slight pain'). There was no difference in the amount of analgesia dispensed to the two groups on the ward post-operatively. In conclusion, topical anaesthesia provides adequate anaesthesia for phacoemulsification. Although a small increase in the level of discomfort was observed, the pain levels reported were small and may not be clinically significant when set against the reduced incidence of anaesthetic-related complications.