The aim of this study is the comparison between the use of bupivacaine alone and a mixture of bupivacaine, mepivacaine and hyaluronidase in both retrobulbar and peribulbar blockades for eye surgery. Three hundred ninety-nine consecutive adult patients scheduled for cataract surgery with regional anaesthesia were included in this prospective, randomized and partially blind study. Peribulbar blockade was performed on 199 patients (group P). Ninety-nine of them received a mixture of local anaesthetics and hyaluronidase (sub-group M), while 100 received bupivacaine alone (sub-group B). Retrobulbar blockade was performed on 200 patients (group R): 100 of them received the mixture with hyaluronidase (sub-group M), while 100 received bupivacaine (sub-group B). The interval between anaesthesia and motor blockade (onset time), the presence of residual ocular movements, the need of further anaesthesia, the quality of anaesthesia, the ocular tone, the length of anaesthesia and possible complications were registered.
Results: Retrobulbar blockade has the only advantage of a shorter onset time, while peribulbar blockade shows a longer anaesthetic effect. Mixture with hyaluronidase (the sub-group M) has a shorter onset time, a lesser need of further anaesthesia, fewer residual ocular movements and a better quality of anaesthesia.
Conclusions: Local anaesthetics mixture with hyaluronidase associated with peribulbar blockade presents the advantages of rapidity, duration and better quality without the risks of retrobulbar blockade side effects.