Comparison of the akinetic properties of subtenon’s anaesthesia versus peribulbar anaesthesia among cataract patients in Nigeria

Abstract

Purpose: This study compared the akinetic properties and anaesthesia-related complications of cataract surgery under peribulbar and subtenon’s anaesthesia. Setting: Department of Ophthalmology, Lagos State University Teaching Hospital, Lagos, Nigeria. Design: Randomized, single-blind controlled clinical trial. Materials and Methods: A total of 100 patients above 18 years with uncomplicated cataract were randomized into the subtenon’s and peribulbar groups. Subtenon’s and peribulbar blocks were achieved with 5 ml of a combination of lidocaine 2% (2.5 ml), bupivacaine 0.5% (2 ml) and 15 IU/ml of hyaluronidase (0.5 ml). Globe akinesia and lid akinesia were assessed at 2, 5 and 10 min after the administration of anaesthesia using a 12-point scale. Chemosis, subconjunctival haemorrhage and other anaesthetic-related complications were also assessed in both the groups. Results: About 77% of the patients in the peribulbar group had successful lid akinesia at 2 min compared with 48.9% in the subtenon’s group (P = 0.007). However, at 5 and 10 min, there was no significant difference in the lid akinesia in both the groups (P > 0.05). The proportion with the globe akinesia in the subtenon’s and peribulbar groups was 14.9 and 48.1% (P = 0.0005) at 2 min, 53.2 and 90.4% (P = 0.0001) at 5 min and 83.0 and 98.1% (P = 0.012) at 10 min, respectively. Chemosis and subconjunctival haemorrhage occurred more in the subtenon’s group, whereas one patient in the peribulbar group had retrobulbar haemorrhage. Conclusion: Even though patients in the subtenon’s group took longer to achieve akinesia of the globe and lids, the absence of a sight-threatening complication makes it generally safer than peribulbar anaesthesia.