The effect of hyaluronidase on akinesia during cataract surgery.

The ability of hyaluronidase to improve akinesis in retrobulbar anesthesia was evaluated in a double-masked study. Forty consecutive patients undergoing cataract surgery were anesthetized with 3 ml of a 1:1 mixture of 4.0% lidocaine and 0.75% bupivacaine solution. In a predetermined randomized fashion, 2 ml of hyaluronidase (300 USP units) were added to half of the syringes, and 2 ml of saline to the remaining half. The level of akinesia was graded in six different positions of gaze. Seventy percent of the hyaluronidase group exhibited complete akinesis, while only 40% of the control group did. The mean scores for four out of six positions of gaze were significantly higher in the hyaluronidase patients than in the control group. Similarly, the hyaluronidase subjects showed a significantly higher sum score for the six sectors than did the control subjects (p = .0001). These results show that hyaluronidase significantly enhances akinesia. It is therefore recommended that it be included in the anesthetic regimen for such surgeries.