II. Indications
- Retrobulbar Hematoma and
- Primary indications
- Secondary indications
- Afferent Pupillary Defect (see Orbital Ultrasound)
- Eye Pain
- Funduscopic changes
- Cherry red Macula
- Pallor of the nerve head
III. Contraindications
- Open Globe Rupture
IV. Precautions
- Increased tension with expanded Retrobulbar Hematoma results in Optic Nerve ischemia
- Vision Loss may occur in as little as 60-90 minutes
- Do not delay Lateral Canthotomy when indicated and not contraindicated
V. Exam
- See Retrobulbar Hematoma
- Confirm no signs of Globe Rupture
- Visual Acuity before and after procedure
- Pupil response (evaluate for Afferent Pupillary Defect)
- Intraocular Pressure (before and after procedure)
VI. Preparation: Equipment
- Sterile gloves
-
Suture kit
- Sterile Instruments: Hemostat (or needle driver), forceps with teeth, iris scissors
- Sterile drapes
-
Anesthetic
- Topical Anesthetic
- Lidocaine 1-2% with Epinephrine in syringe with 30 gauze, 1 inch needle
- Miscellaneous
- Antiseptic (e.g. Chlorhexidine)
- Saline irrigation fluid
VII. Technique
- Preparation
- Perform exam as above including Intraocular Pressure
- Patient supine with head of bed at 20-30 degrees
- Assistant stabilizes head and retracts Eyelids
- Lateral Canthus Incision
- Inject 1-2 ml Lidocaine 1% into lateral canthus, away from globe along horizontal tract planned to cut
- Apply hemostat to clamp lateral canthus skin in horizontal line laterally 1-2 cm long and leave in place 1 minute
- With iris scissors, cut along clamped tissue to create a 1-2 cm horizontal incision from lateral canthus, laterally
- Avoid incision >2 cm (risk of Facial Nerve - temporal branch injury)
- Inferior Crus of Lateral Canthal ligament incision (inferior Cantholysis)
- Use forceps to retract the lateral lower Eyelid
- Identify the inferior crus of the lateral canthal ligament (tense like a guitar string)
- Cut the inferior crus with iris scissors directed away from globe, inferoposteriorly toward orbital rim
- Avoid injuring superior structures (lacrimal artery, lacrimal gland, levator Muscle)
- Superior Crus of Lateral Canthal ligament incision (superior Cantholysis)
- Indicated after inferior Cantholysis if recheck Intraocular Pressure still > 40 mmHg
- Use forceps to retract the lateral upper Eyelid
- Identify the superior crus of the lateral canthal ligament (also tense like a guitar string)
- Cut the superior crus with iris scissors directed away from globe, superoposteriorly toward orbital rim
- Bandage
- Apply topical eye ointment (e.g. Erythromycin 5% ointment)
- Apply eye shield or cup over the affected eye
VIII. Disposition
- Emergent ophthalmology evaluation
IX. Resources
- Lateral Canthotomy (Eye Guru)
- Lateral Canthotomy (WikiEM)
- Video (EM:Rap, Dr. Mason)
- Video (Healthpartners)
X. References
- Azih, Silmi and Patel (2022) Crit Dec Emerg Med 36(5): 18-9
- Amer (2019) J Emerg Med 56(3): 294-7 [PubMed]