Advanced Subconjunctival Anesthesia for Cataract Surgery

Ocular regional blocks generally require blind instrumentation to the posterior orbit, leading to rare but serious complications. However, topical anesthesia does not suppress eye or lid movements and may lead to more surgical complications. Advanced subconjunctival anesthesia (ASCAN) is a technique developed to provide reliable akinesia and anesthesia without anterior dissection or blind intrusion into the posterior orbit, while allowing visualization of the needle-tip position.

Nonrandomized case series at a rural health service.

Advanced subconjunctival anaesthesia was performed on 60 elective adult patients undergoing phacoemulsification surgery. The technique involves piercing the conjunctiva and Tenon's capsule in the superior outer quadrant of the globe with a 25-gauge, 16 mm needle, using either lignocaine 2% plain or in equal mix with bupivicaine 0.5%. Up to 10 mL of anesthetic with hyaluronidase 30 IU/mL is injected in a posterior direction into the sub-Tenon's space. Ocular motor functions were assessed 10 minutes after ASCAN using a Brahma scale. Pain was assessed during surgery and at the end of surgery after subconjunctival injection of antibiotic and steroid using a verbal Numeric Rating Scale.

All patients completed surgery without needing supplemental anesthesia. Fifty-eight patients (97%) were pain free, whereas 2 patients experienced transient mild pain. Adequate globe akinesia and reliable lid paralysis was achieved comparable to other studies, with no major surgical or anesthetic complications.

Advanced subconjunctival anesthesia is a visually guided, minimally invasive technique, achieving satisfactory analgesia and akinesia for phacoemulsification surgery.