The peribulbar block technique was developed to minimize the risk of injury to structures within the intraconal space. It is performed by injection into the extraconal space using larger volumes of local anesthetic (eg, up to 12 mL). The larger volume is necessary for its spread into the entire corpus adiposum of the orbit and eyelids to block the orbicularis muscle.
Fourteen randomized, prospective, controlled studies evaluating hyaluronidase in peribulbar blocks in nearly 1,800 patients were reviewed and analyzed. These studies involved a variety of local anesthetic combinations and hyaluronidase doses (ranging from 3.75 to 300 IU/mL). The end points included akinesia, induction time, need for supplementary block, and volume of local anesthetic. Evidence of improvement in peribulbar block with hyaluronidase is equivocal. Approximately half of the studies show a benefit to including hyaluronidase, whereas the rest demonstrate equivalence across a range of hyaluronidase doses.
Hyaluronidase was well tolerated. In some of these studies, fewer complications such as increased IOP were observed in patients who received hyaluronidase. Although hyaluronidase does not consistently improve peribulbar block efficacy, it is beneficial for its effects on facilitating the spread of larger volumes of anesthetic and reducing complications.
WA-008 Rev 01/2018