Orbital Compartment Syndrome

Objectives

To support the recognition and immediate management of orbital compartment syndrome.

Scope

This guideline describes the signs and symptoms of orbital compartment syndrome and the immediate management by a non-specialist.

Although all cases of suspected or proven orbital compartment syndrome will require specialist discussion and likely in-person review, this guideline describes immediate management that should not be delayed while waiting for a specialist opinion. 

Audience

This guideline is intended for the use of registered healthcare professionals fulfilling a role in a forward medical location or in an emergency department on deployed operations

Background

Orbital compartment syndrome is a sight-threatening emergency usually caused by retro-bulbar haemorrhage into the confined orbital space behind the eye.

Orbital compartment syndrome is most likely to occur secondary to blunt trauma, and can be associated with any facial trauma.  It can cause irreversible profound sight loss within two hours: the earlier this process is reversed the less permanent disability is likely.

Early recognition and intervention are vital to optimising visual outcome. Treatment should not be delayed waiting for radiological confirmation of a clinical diagnosis, or for an ophthalmologist.

Initial Assessment & Management

Symptoms:

• Severe eye pain
• Profound vision loss

Signs:

• Proptosis
• Restricted eye movements
• Poor visual acuity and/or reduced colour vision
• High intraocular pressure (which can be assessed using digital pressure over closed lids) and comparison with the unaffected eye, or your own eye if the patient’s contralateral eye is also injured.
• Subconjunctival haemorrhage
• Swollen and bruised lids
• Relative afferent pupillary defect

Management: Lateral canthotomy and cantholysis (LCC) then evacuation to a surgical facility, ideally with an ophthalmologist present. This procedure is sight-saving and should be attempted by those who are capable even in the absence of prior experience.

Step by step guide:

1. Obtain verbal consent
2. Local anaesthetic infiltration – superficially to skin at the canthus and down to the periosteum lateral to the orbital rim. Do not inject towards the globe, do not inject deep to the lateral orbital rim or inside the orbit. Using local anaesthetic with adrenaline, if readily available, will help with haemostasis.
3. Use a clamp (ideally an artery clamp) to crush tissues between the lateral canthus and orbital rim to improve haemostasis, applying pressure for at least 1 minute.
4. Initial skin incision – (this can be combined with canthotomy in one go by using a pair of scissors if easier) – aim to extend at least to the limit of the orbital rim (lateral limit of the eyebrow). In an emergency situation it is fine to extend this further if required to improve access to the inferior crus and visualisation.
5. Canthotomy – cut through the lateral canthus (where upper and lower lid meet) and tendon, all the way to the end of your skin incision using scissors. Accomplish this by starting at the lateral canthus, cutting away from the globe and aiming ANTERIOR to the orbital rim. DO NOT cut down towards the inside of the orbit or the globe.
6. Distract the lower lid away from the globe.
7. Strum the inferior crus with the tips of closed scissors
8. Cut the inferior crus by aiming inferiorly, parallel with the patient’s face with the scissor blades either side of the tough crus.
9. Continue to cut until the tension on the lower lid is entirely released (it can generally be flapped down onto the patient’s cheek it this point)

How do you know it has worked?

• The eye may be seen to physically prolapse further forward as the tension is released
• Blood may be seen escaping the orbit
• Patient may report reduced pain and improved vision
• Improved pupillary response to light
• Improved intraocular pressure

What if it has not worked?

If no response or further deterioration despite cantholysis and canthotomy, consider IV mannitol (0.5–2g) and IV acetazolamide (500mg).

Advanced Assessment & Management

Immediate management in the deployed hospital context will follow the same approach described above.

Following the LCC procedure, imaging should be performed (CT if available, otherwise XR facial views and orbits), but the immediate management of orbital compartment syndrome must not be delayed for imaging.

Prolonged Casualty Care

• Orbital compartment syndrome is usually self-limiting within 2-4 hours.
• Maintain patient comfort and prevent further damage.
• Protect eye with rigid shield.
• Keep head of bed elevated to 30-45 degrees.
• If significantly contaminated, irrigate eye with sterile water if available.
• Contact lenses should not be worn while the eye recovers.
• Consider prophylactic antibiotics.
• Dress the periocular wound (ideally with a paraffin-impregnated dressing such as Jelonet, if available, and pad/gauze). If performed properly and tissues are repositioned in the correct anatomical orientation, the surgical wounds can heal adequately by secondary intention without need for further repair.
• Monitor the eye for re-accumulation of the tamponade

Paediatric Considerations

In the context of deployed care there are no practical differences in the immediate management of blunt eye injuries.  The main consideration would be in relation to drug dosages.