Orbital Decompression - Lateral Canthotomy & Cantholysis

Lateral canthotomy (incision of lateral canthus) and cantholysis (cutting of the inferior canthal tendon) are stepwise sight saving procedures performed in the setting of acute orbital compartment syndrome. This most commonly occurs with a traumatic retro-bulbar haematoma. Although the incidence of retro-bulbar haemorrhage is rare, delay in intervention can lead to visual loss.


Acute orbital compartment syndrome (OCS) 

Unconscious Patient:

  • Afferent pupillary defect (Marcus-Gunn pupil) - MOST RELIABLE INDICATOR
  • Intra-ocular pressure (IOP) > 40mmHg. 

Awake Patient

  • Decreased visual acuity (< 6/18) and proptosis
  • Decreased visual acuity (< 6/18) and afferent pupillary defect
  • Decreased visual acuity (< 6/18) and intra-ocular pressure > 40mmHg. 

The morbidity of the procedure is low; if in doubt, the procedure should be performed.

Note: The diagnosis is clinical. While a CT or MRI scan may help to establish the diagnosis, patients with rapidly evolving symptoms and signs consistent with raised IOP, in the setting of trauma, require immediate treatment. 


  • Globe rupture (diagnosis can be difficult; IOP may be < 5mmHg)

Join us at The Procedures Course in Melbourne to practice this and other life and limb saving procedures.


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