Peribulbar versus sub-Tenon block in cardiac patients undergoing cataract surgery during warfarin therapy

Abstract

Objective: To compare sub-Tenon’s block with peribulbar block in patients on oral warfarin therapy undergoing cataract surgery. Materials and methods: We studied 100 patients on warfarin undergoing cataract surgery; randomly allocated into one of two groups; sub-Tenon’s group (group S, n = 50), and peribulbar group (group P, n = 50). In group (S), sub-Tenon’s injection of 3–5 ml of anesthetic agent was done using a 25 mm sub-Tenon’s cannula. In group (P), the peribulbar block with 3–4 ml of 2% lidocaine–hyaluronidase (10 IU/ml) and 0.5% bupivacaine was done. Pain and akinesia and postoperative complications were assessed. Results: Sub-Tenon group showed significantly higher frequency of hemorrhage compared to peribulbar group (30% versus 8%, p = 0.041), mainly of grade I. The two groups had comparable frequency of subconjunctival hemorrhage (p = 1.000). No patients experienced sight-threatening hemorrhagic complications. Pain was significantly lower in the sub-Tenon group. Akinesia was significantly better (p = 0.025) 2 min after injection and comparable from 4 to 10 min after injection in the peribulbar group. The majority of patients in the two groups reported satisfaction (p = 0.372). The surgeon expressed higher satisfaction with peribulbar block (94%) compared to sub-Tenon’s block (81%) (p = 0.064). Conclusion: Peribulbar and sub-Tenon techniques were relatively safe in patients on anticoagulants during cataract operation. We recommend peribulbar technique owing to significantly less bleeding and more satisfactory akinesia response and hence surgeon comfort.

Keywords

• Subtenon
• Peribulbar block
• Oral anticoagulant
• Cataract surgery