Procedure: Lateral Canthotomy

Procedure, instructions and discussion

Lateral canthotomy and cantholysis

Peisah RI, Ostrowski K. Emergency management of orbital compartment syndrome: Lateral canthotomy and cantholysis case series. Australas Emerg Care. 2024 Sep 27:S2588-994X(24)00055-1.

Detailed written instructions and explanation are available in our Free App (iOS and Android). This video is hot off the press and we want your help improving it. Drop us a line with any suggestions

Instructions

Indication

Blunt eye trauma (suspected retrobulbar haematoma)

Plus, any of the following

• Decreased visual acuity
• Raised intraocular pressure (>40 mmHg)
• Relative afferent pupillary defect
• Proptosis

Or

CT scan findings of orbital compartment syndrome, which are:

• Stretching of the optic nerve
• Tenting of the globe
• Retrobulbar haemorrhage with proptosis

THE SERIOUSLY INJURED TRAUMA PATIENT WITH A CLOSED EYE IS AT RISK OF HAVING A SIGHT THREATENING ORBITAL COMPARTMENT SYNDROME (OCS) MISSED DUE TO INABILTY TO TALK TO THE PATIENT OR EASILY VISUALISE THE EYE

EXAMINATION OF THE EYE IS AN ESSENTIAL PART OF THE INITIAL TRAUMA ASSESSMENT

Contraindications (ABSOLUTE/relative)

Suspected globe rupture (globe laceration, irregular pupil, hyphaema, IOP < 5)

WHILE LATERAL CANTHOTOMY IS NOT INDICATED FOR GLOBE RUPTURE, THERE IS SOME OVERLAP IN THE SIGNS SUGGESTIVE OF GLOBE RUPTURE AND ORBITAL COMPARTMENT SYNDROME (DIFFUSE CHEMOSIS, OPHTHALMOPLEGIA). IF IN DOUBT LATERAL CANTHOTOMY SHOULD BE PERFORMED, WHILE AVOIDING PRESSURE ON THE GLOBE.

Alternatives

• None

Consent

VERBAL – IF HAS CAPACITY

• Simple procedure with a low risk of complications

NOT REQUIRED – IF LACKS CAPACITY

• Emergency procedure to save sight

Potential complications

• Failure (incomplete cantholysis)
• Globe injury
• Lacrimal artery, gland and muscular injury
• Bleeding
• Infection

Infection control

• Standard precautions PPE
• Sterile gloves and gown, surgical mask, eye protection

Area

• Any bedspace

Staff

• Procedural clinician
• Assistant

Equipment

• 5ml syringe with 25g needle for infiltration
• Straight haemostat
• Tissue forceps x 2
• Iris Scissors (Suture scissors as an alternative)

A PRE-PREPARED LATERAL CANTHOTOMY BOX IF RECOMMENDED. THE CORRECT SCISSORS SIGNIFICANTLY IMPROVE THE EASE OF PROCEDURE.

Positioning

• Supine

Medication

• Amethocaine 0.5-1% drops
• Lignocaine 1-2% with adrenaline (1:100,000) 5ml

Sequence (lateral canthotomy and cantholysis)

• Apply 1-2 drops of amethocaine to affected eye
• Inject 1-2ml of lignocaine with adrenaline into the lateral canthus directing needle tip away from the globe
• Irrigate eye with normal saline to clear debris
• Crimp lateral canthus with haemostat to the orbital rim for one minute, then remove
• Incise 1cm with scissors from lateral corner of the eye extending laterally outward to orbital rim
• Retract the inferior eyelid with forceps and identify the inferior crus of the lateral canthal tendon
• Incise inferior crus of the lateral canthal tendon infero-posteriorally with scissors (cantholysis)
• Reassess eye for improvement in visual acuity, resolution of RAPD, with IOP <40mmHg
• If no improvement, confirm cantholysis (lower eyelid freely mobile, no tendon palpable with forceps), then proceed to divide the superior crus of the lateral canthal tendon

Post-procedure care

• Apply moist gauze dressing
• Urgent ophthalmology discussion and review
• Reassess visual acuity and RAPD after 30 minutes
• Provide analgesia
• Document (completion, technique and complications)

Tips

This is a sight saving procedure with low risk of significant complications. The procedure should be performed as soon as possible once the diagnosis is made due to its time critical nature and to reduce the risk of permanent visual loss.

Discussion

Orbital compartment syndrome is a sight-threatening emergency usually caused by intra-orbital haemorrhage post trauma. Bleeding into the fixed orbital space increases pressure resulting in ischaemia of the optic nerve and retina with potentially irreversible visual loss.

Accurate clinical assessment can be improved by retracting the eyelids with gauze or paperclips. Orbital decompression is a low morbidity procedure, with simple incisions that will often heal without intervention or are easily repaired. 

If there is a reasonable suspicion of orbital compartment syndrome the procedure should be performed without CT imaging, as diagnostic delay worsens outcomes. Where clinical assessment is impaired by reduced LOC, or a closed swollen eye and orbital compartment syndrome is considered possible but unlikely, a rapid CT can be considered. CT scan findings suggestive of orbital compartment syndrome include retrobulbar haemorrhage with proptosis, stretching of the optic nerve and tenting of the globe.

Normal intraocular pressure is 10 – 21 mmHg. Multiple papers cite a pressure ≥40 mmHg as an indication for lateral canthotomy, evidence supporting this strict cutoff is limited and the eye can see no better than hand motion or light perception with a pressure > 30 mmHg.

Pain from this procedure can often be controlled with local anaesthetic. For an awake patient procedural sedation can be offered for patients provided it does not significantly delay the procedure.

References

• Rowh AD, Ufberg JW, Chan TC, Vilke GM, Harrigan RA. Lateral canthotomy and cantholysis: emergency management of orbital compartment syndrome. J Emerg Med. 2015 Mar;48(3):325-30
• Gilmartin S. Retrobulbar heamorrhage and lateral canthotomy.
• Peisah RI, Ostrowski K. Emergency management of orbital compartment syndrome: Lateral canthotomy and cantholysis case series. Australas Emerg Care. 2025 Mar;28(1):67-71. 
• Gardiner MF. Approach to eye injuries in the emergency department. In: UpToDate. Waltham (MA): UpToDate. Dec 13, 2023.
• Ballard SR, Enzenauer RW, O’Donnell T, Fleming JC, Risk G, Waite AN. Emergency lateral canthotomy and cantholysis: a simple procedure to preserve vision from sight threatening orbital hemorrhage. J Spec Oper Med. 2009 Summer;9(3):26-32
• McInnes G, Howes DW. Lateral canthotomy and cantholysis: a simple, vision-saving procedure. CJEM. 2002 Jan;4(1):49-52
• Mohammadi F, Rashan A, Psaltis A, Janisewicz A, Li P, El-Sawy T, Nayak JV. Intraocular pressure changes in emergent surgical decompression of orbital compartment syndrome. JAMA Otolaryngol Head Neck Surg. 2015 Jun;141(6):562-5
• Rixen J, Verdick R, Allen RC, Carter KD. Lateral canthotomy and cantholysis. Eyerounds.org. Iowa City, IA: University of Iowa Healthcare; 2013.
• Roberts JR, Custalow CB, Thomsen TW. Roberts and Hedges’ clinical procedures in emergency medicine and acute care. 7th ed. Philadelphia, PA: Elsevier; 2019.
• Dunn RJ, Borland M, O’Brien D (eds.). The emergency medicine manual. Online ed. Tennyson, SA: Venom Publishing; 2019.

The App