A Retrobulbar block may be preferred for certain procedures that would benefit from lower volumes of local anesthetic (ie, 3-5 mL).
Although retrobulbar blocks are used less commonly than peribulbar blocks because of potential anatomic risk factors associated with administration and the need for an additional facial nerve block to prevent blinking, they may still be preferred for certain procedures that would benefit from lower volumes of local anesthetic (ie, 3-5 mL). Nine randomized, prospective, controlled studies evaluating hyaluronidase added to retrobulbar blocks in more than 1,300 patients were reviewed. A variety of anesthetic mixtures and hyaluronidase doses (ranging from 0.75 to 200 IU/mL) were used. The end points included akinesia, induction time, need for supplementary block, and volume of local anesthetic. The addition of hyaluronidase to retrobulbar blocks generally resulted in improved akinesia and was well tolerated. Fewer complications, such as a lower tendency for prolapse, were observed in patients who received hyaluronidase. Overall, a dose between 3.75 and 75 IU/mL hyaluronidase in retrobulbar blocks appears sufficient to provide a beneficial effect on akinesia.
WA-010 Rev 01/2018