Orbital compartment syndrome: how do I perform lateral canthotomy and cantholysis?

Summary

Emergency lateral canthotomy and cantholysis is a sight-saving decompression procedure for orbital compartment syndrome from retrobulbar haemorrhage or other causes of rapidly elevated orbital pressure. Perform urgently when there is blunt eye trauma with decreased visual acuity, proptosis, RAPD, or markedly elevated IOP; do not delay for CT if clinical suspicion is high.

Indications
  • Blunt eye trauma with suspected retrobulbar haemorrhage and decreased visual acuity
  • Raised intraocular pressure >40 mmHg or rapidly progressive vision loss/proptosis
  • Relative afferent pupillary defect or CT findings of orbital compartment syndrome (optic nerve stretching, globe tenting, retrobulbar haemorrhage with proptosis)
Contraindications
  • Suspected globe rupture with globe laceration, irregular pupil, hyphaema, or very low IOP
  • Relative contraindication only; if in doubt and OCS suspected, proceed while avoiding pressure on the globe
Complications
  • Failure from incomplete cantholysis
  • Globe injury or bleeding
  • Infection or lacrimal/muscular injury

Equipment

  • Essential: 5 mL syringe with 25 g needle, straight haemostat, iris scissors
  • Optional: tissue forceps, topical amethocaine, Morgan lens, sterile drapes/gown/gloves

Positioning and Landmarks

  • Position: Supine, head turned away from affected side
  • Landmarks/US: Lateral canthus and inferior crus of the lateral canthal tendon; point all instruments away from the globe toward the orbital rim

Analgesia/Sedation

OptionWhenKey note
Topical amethocaine + local lignocaine with adrenalineMost awake patientsInject 1–2 mL into lateral canthus with needle directed away from globe
Procedural sedation/anxiolysisAgitated or distressed patient if no delayDo not delay decompression for sedation

Steps

  1. Apply topical anaesthetic, prep the lateral canthus, and infiltrate local anaesthetic with all instruments directed away from the eye.
  2. Irrigate debris if present, then clamp/crimp the lateral canthus with a haemostat against the orbital rim for about 1 minute.
  3. Perform the canthotomy: incise the lateral canthus full thickness 1–2 cm laterally toward the orbital rim.
  4. Perform inferior cantholysis: retract the lower lid, identify or palpate the inferior crus (“guitar string” feel), then cut infero-posteriorly until the lower lid becomes freely mobile.
  5. Reassess vision and IOP; if inadequate improvement, confirm complete inferior release and divide the superior crus.

Post-procedure

  • Confirm: Improvement in visual acuity/RAPD and reduction in IOP (<40 mmHg suggested target)
  • Aftercare: Moist gauze dressing, analgesia, urgent ophthalmology consultation/review
  • Re-check: Repeat visual acuity, RAPD, globe assessment, and IOP after 30 minutes

Gallery

References

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