Ultrasound detection of iatrogenic injury during peribulbar eye block: a cadaveric study

Amy Sadler (Lead / Corresponding author), Graeme McLeod, Paul G. McHardy, Tracey Wilkinson

Research output: Contribution to journalArticlepeer-review

6 Citations (Scopus)
160 Downloads (Pure)


Background: Ophthalmic eye blocks, such as retrobulbar, peribulbar and sub-Tenon's, are traditionally conducted "blind". Complications are rare but potentially devastating. Life-threatening complications include brain stem anesthesia and local anesthetic toxicity, whereas sight-threatening complications include globe perforation, optic nerve damage and ocular muscle damage. Ultrasound permits a view of orbital structures and can be used to guide needle placement. The ultrasound appearances of unintended local anesthetic injection into vital orbital structures have not been documented. This study aimed to record the ultrasound appearances of unintended injection locations.

Methods: The spherical shape of the eyeballs of three soft-fix Thiel embalmed human cadavers were restored using glycerol. Iatrogenic injury in peribulbar block was then simulated through injection of printers' ink mixed with Thiel embalming fluid. Ultrasound was used to guide the needles and the tips were redirected to lie within the globe, lateral rectus and optic nerve. Ultrasound images were recorded during injection. The orbital cavities were then dissected via a superior approach to record the location and extent of injectate spread.

Results: Real-time globe rupture, ocular muscle injection and optic nerve injection were visible using ultrasound. Characteristic appearances were identified in each case. Dissection confirmed needle and injection placement.

Conclusions: The ultrasound appearance of block complications is important to document and should be an integral part of regional anesthesia training. This study is the first to provide such images for ophthalmic nerve blocks. It offers ophthalmic anesthetists and ophthalmologists the potential to diagnose severe complications rapidly and accurately with a potential impact on patient safety.

Original languageEnglish
Pages (from-to)740-743
Number of pages4
JournalRegional Anesthesia and Pain Medicine
Issue number9
Early online date15 Jul 2020
Publication statusPublished - 1 Sept 2020


  • anatomy
  • head and neck
  • nerve injury
  • regional anesthesia

ASJC Scopus subject areas

  • Anesthesiology and Pain Medicine


Dive into the research topics of 'Ultrasound detection of iatrogenic injury during peribulbar eye block: a cadaveric study'. Together they form a unique fingerprint.

Cite this