Our First Experiences of Incisionless Sub-Tenon’s Block for Cataract and Vitroretinal Surgery

ARUD 2023: Balkan States Anesthesia Days - VII, Ankara, Türkiye, 28 Nisan 2023, cilt.31, ss.266

ABSTRACT

Background: Sub-Tenon’s block (STB) is a technique of ophthalmic regional anesthesia. It has a good risk profile, in that sight- and lifethreatening

complications are extremely rare. STB has gained popularity in the last three decades, with refinements including different types

of blunt metal cannula, plastic cannulae and ‘incisionless’ approaches (1). The incisionless type of STB has lower rate of regional ophthalmic

anesthesia complications (2,3). In Türkiye, sub-Tenon’s block anesthesia is employed by a few anesthesiologists. In this study, the clinical

outcomes of our first STB experiences.

Material and Methods: Eighteen adult patients who underwent cataract and vitroretinal surgery under incisionless STB were included. In the

anestetic management, the patients were sedatizated with dextmetodomidine, midazolam and fentanyl. The conjunctiva was anesthetized

with topical proparacaine (0,5%). The conjunctiva was then grasped 5 mm from the limbus using toothed forceps. For incisionless STB, an

intravenous cannula was used to administer a mixture of bupivacaine (0.5% ) and lidocaine (2%). The RAMSEY sedation scores, visual analogue

pain score, need of painkiller, the presence of vomitting, and FAST-TRACK recovery scores of the patients were recorded before block, at 15th

minute of block, just after the operation, postoperative 3rd hour and 1st day. Movement of eyelid and eye globe, the presence of chemosis,

petechiae, and subconjunctival hemorrhage were noted.

Results: There were 12 females and 6 males with a mean age of 68 years old. Almost all patients were ASA 1-2 physical status. Cataract and

vitroretinal surgery were performed in 10 and 8 patients, respectively. No major complication was observed. Of the 18 patients, 14 were

very satified, 3 were satified and 1 was unsure for the procedure. On the other hand, the surgeons were very satisfied for the block in 17

operations.

Conclusions: This method seeks to avoid the risks of retrobulbar haemorrhage, perforation of the globe, damage to the optic nerve, and

injection into the subarachnoid space, whilst providing prolonged and reliable anaesthesia. Thanks to this block, providing a high akinesia rate

is one of the most important gains of this technique. Similarly, this new technique, minimally invasive and incisionless sub-Tenon’s block, was

highly successfull and safe in our case series.

Keywords: Opthtalmic regional anesthesia, sub-tenon’s block, outcome