Peribulbar anaesthesia with 1% ropivacaine and hyaluronidase 300 IU ml(-1): comparison with 0.5%bupivacaine/2% lidocaine and hyaluronidase 50 IU ml(-1)

The low toxicity of ropivacaine makes it attractive for peribulbar anaesthe sia. However, its motor-sparing properties are undesirable when akinesia is important. Hyaluronidase (300 IU ml(-1)) promotes the onset and quality of peribulbar blockade when used with other agents. We investigated the onset and quality of ocular akinesia in 80 patients randomized to receive 1% rop ivacaine plus hyaluronidase 300 IU ml(-1) (group 1), or bupivacaine 0.5%/Li docaine 2% plus 50 IU ml(-1) hyaluronidase (group 2). Ocular akinesia was s cored from 0 (no movement) to 8 (full movement) every 2 min for 20 min. The groups showed no difference in the rate of onset or degree of akinesia ach ieved (analysis of variance with repeated measures; P = 0.34). Sixty per ce nt of patients in group 1 and 55% in group 2 achieved akinesia scores of le ss than or equal to 4 by 6 min (chi(2) test; P = 0.5). We conclude that bot h peribulbar solutions produce equivalent onset and quality of ocular akine sia.