Orbital compartment syndrome and lateral canthotomy
- Emergency
Bleeding behind the eye after a blow or surgery can choke the optic nerve. A lateral canthotomy within the first two hours can save the eye.
See it in 3D: Optic nerve · Eyelids
What it is
The orbit is a closed bony box. Bleeding behind the eye (retrobulbar haemorrhage), usually after facial trauma, eyelid or sinus surgery, or in anticoagulated patients, raises the pressure inside it and cuts the blood supply of the optic nerve and retina. Sight can be lost in about 90 to 120 minutes. Cutting the lateral canthal tendon (lateral canthotomy and cantholysis) releases the pressure and is done at the bedside without waiting for imaging.
How to recognise it
- Proptosis with a tense, rock-hard orbit that resists gentle backward pressure.
- Falling visual acuity and an afferent pupillary defect.
- Severe pain, restricted eye movements and tense lid swelling.
- Very high eye pressure on tonometry.
- Recent trauma, orbital or sinus surgery, or anticoagulation.
What to do at once
- Recognise it clinically; do not delay treatment for a CT scan.
- Clean the lateral canthus and inject local anaesthetic with adrenaline.
- Crush the skin of the lateral canthus with a straight clamp for about a minute.
- Cut the lateral canthus horizontally towards the bony rim (canthotomy).
- Find and cut the inferior limb of the lateral canthal tendon (cantholysis) until the lower lid moves freely; cut the superior limb if needed.
- Recheck acuity, the pupil and eye pressure, then refer urgently.
Mistakes that cost sight
- Canthotomy alone without cantholysis rarely lowers the pressure enough.
- The procedure is done by emergency doctors in many settings because the time window is short.
- Complications such as bleeding or lid malposition are minor compared with losing the eye.
Next step / Initial management
- After decompression: urgent ophthalmology and imaging (CT of the orbits) to find the cause.
- Correct anticoagulation and treat the source of bleeding.
- Monitor vision and pressure; surgical drainage may be needed if the pressure rises again.
- The lid wound usually heals well or is repaired later by oculoplastics.
Test yourself
Think of the answer, then tap the question to see it.
What is the treatment of orbital compartment syndrome?
Immediate lateral canthotomy with inferior cantholysis at the bedside, without waiting for imaging.
Why is it a time-critical emergency?
Because the raised orbital pressure cuts the blood supply of the optic nerve and retina, and sight can be lost within about two hours.
Which patients are at higher risk?
Those with facial trauma, recent orbital, eyelid or sinus surgery, and those taking anticoagulants.
Connections
See it in 3D2
The structures of Durgical's 3D anatomy where it is found.
Educational content; not a clinical guideline and no substitute for assessment by a health professional. For sudden visual loss, severe eye pain, a chemical burn or an eye injury, go to an emergency department at once.
Sources: Lateral Orbital Canthotomy (StatPearls Publishing (NCBI Bookshelf), 2023).
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Representative model, for educational purposes only.