Enhanced precision and safety in cataract surgery: A case series on ultrasound-guided peribulbar block

Sir, Peribulbar anesthesia, a widely used technique for cataract surgeries, is traditionally administered through landmark-guided injections. While this method is effective, it carries several risks, including the potential for orbital penetration, intravascular injection, failure to anesthetize the eye, ocular motor paralysis, infection, allergies, retrobulbar hemorrhage, optic nerve injuries, inadequate pupil dilation, and in severe cases, loss of vision.[1] Pulmonary edema has also been reported.[2] Given these risks, using ultrasound (USG)-guided techniques has been proposed to reduce complications. Our review of landmark-guided blocks, which were later evaluated by USG, revealed some local anesthetic deposition far from the target area. This led to delayed onset or inadequate anesthesia. To address this, we conducted a case series involving eight patients who underwent ultrasound-guided peribulbar block (USG-PBB). In this approach, we administered 4 ml of 0.5% bupivacaine in the superior quadrant near the eye as a single-point injection [Figure 1]. The USG enabled precise guidance of the needle to the targeted area, ensuring accurate local anesthetic delivery and intraconal spread while avoiding injury to surrounding vulnerable structures. This resulted in immediate, dense motor block, highlighting the precision and effectiveness of USG-PBB. The outcomes were favorable: all patients experienced an immediate onset of anesthesia, and seven out of eight achieved satisfactory motor block within 5–7 min. One case required an additional 2 ml inferiorly for sufficient akinesia. USG’s ability to visualize the eye and surrounding structures ensured the block’s efficacy and safety.Figure 1: (a) The placement of the ultrasound probe and needle, (b) Ultrasound image of the orbit and contents. G: Globe, ON: Optic nerve, PB: Peribulbar space, RB: Retrobulbar spaceWhile both landmark and USG-PBB techniques are well-established, the latter is gaining attention for its potential advantages. Despite the clear benefits of USG-PBB, its widespread adoption has been limited by several factors. The unavailability of USG machines in some settings and the need for trained personnel present a significant barrier to its broader use. Moreover, advances in microincisional surgery and the growing use of topical anesthesia have reduced the overall demand for PBBs in ophthalmic surgeries. Our case series demonstrated satisfactory anesthesia with single-point USG-PBB, consistent with other studies showing a 93% success rate for USG-PBB, compared to 84.8% for landmark-guided blocks, and fewer complications with the USG guidance.[3] In addition, precise USG-guided local anesthetic delivery enables immediate intraconal spread, correlating with effective akinesia and anesthesia.[4] Therefore, the accurate visualization of needle trajectory and local anesthetic deposition with USG-PBB allows for reduced anesthetic volume, effective blockade, and lower complication rates, making it an attractive alternative. Moreover, the visualization of the globe and adnexa ensures a safer block in patients with myopia and staphyloma who are at high risk of globe perforation with a landmark-guided technique.[5] Randomized trials are needed to explore the potential benefits of USG-PBB and encourage its increased use in ophthalmic anesthesia. Our case series adds to the expanding evidence that underscores the benefits of USG guidance. It emphasizes the significance of precision, the block’s efficacy without complications, and the accuracy that leads to improved patient outcomes. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.