From the Research
Canthotomy should be performed immediately in cases of orbital compartment syndrome to relieve pressure and prevent permanent vision loss, as evidenced by the most recent study in 2023 1.
Indications for Canthotomy
The procedure is most commonly performed when trauma or bleeding behind the eye causes increased pressure that threatens vision by compressing the optic nerve or restricting blood flow. Signs of orbital compartment syndrome that necessitate canthotomy include:
- Decreased visual acuity
- Afferent pupillary defect
- Proptosis (bulging eye)
- Increased intraocular pressure
Procedure
To perform the procedure, the area is anesthetized with local anesthetic (such as 1-2% lidocaine with epinephrine), hemostats are applied to crush the lateral canthus for 1-2 minutes, and then scissors are used to make a 1-2 cm horizontal cut at the lateral canthus, followed by identifying and cutting the inferior crus of the lateral canthal tendon.
Success Rates and Outcomes
The success rate of a lateral canthotomy is comparable amongst emergency medicine and ophthalmology providers, with a success rate of 68% vs 79.2%, respectively (p = 0.413) 1. Poorer visual outcomes are associated with the initial failure of a lateral canthotomy and head trauma without an orbital fracture. All patients treated with a vertical lid split procedure met the criteria for 'success' as defined by the study 1.
Alternative Tools and Techniques
In resource-poor settings, alternative tools such as a multitool and a #11 scalpel blade can be used to perform a lateral canthotomy and cantholysis 2. The procedure can be performed at the bedside with simple instruments, and emergency physicians should be familiar with lateral canthotomy and cantholysis to minimize the chance of irreversible visual loss 3.
Importance of Prompt Decompression
Prompt decompression is essential for visual recovery in orbital compartment syndrome, with maximal recovery if performed within 2 hours of injury 4. The procedure should be performed immediately when signs of orbital compartment syndrome are present to prevent permanent vision loss.