Comparison of analgesia and akinesia after retrobulbar injections at different speeds

PURPOSE. To assess how the speed of injection of local anesthetic solutions affected pain of injection, bulbar akinesia and analgesia with retrobulbar anesthesia (RBA). METHODS. 70 patients undergoing RBA for cataract surgery were enrolled in a prospective masked trial. They were allocated randomly to receive 5 ml ane sthetic solution injected either within 20 seconds (group A) or within 60 s econds (group B). Additionally, akinesia of the orbicularis muscle was crea ted according to O'Brien's technique. The pain of injection was registered on an ordinal analogue scale immediately before and after RBA. The followin g data were collected before and 20 minutes after retrobulbar injection: ey e motility (Kestenbaum test), and corneal sensitivity (or no sensitivity; 1 : sensitivity remaining). Data were also collected on age, sex, and bulbar length, and any side effects of the intervention. RESULTS. Injection pain did not differ in the two groups. After RBA horizon tal and vertical eye motility was slightly lower in group A than group B. P ersistent motility was found in 18 patients in group A and 16 in group B. M edian horizontal and vertical motility was 0 mm in both groups. Four patien ts in group A and five in group B had corneal sensitivity persisting after RBA. CONCLUSIONS. This comparison of different injection velocities brought to l ight no significant differences regarding bulbar analgesia and akinesia aft er RBA.