II. Indications

  1. Retrobulbar Hematoma and
  2. Primary indications
    1. Proptosis
    2. Intraocular Pressure >40 mmHg
    3. Decreased Visual Acuity
  3. Secondary indications
    1. Afferent Pupillary Defect (see Orbital Ultrasound)
    2. Eye Pain
    3. Funduscopic changes
      1. Cherry red Macula
      2. Pallor of the nerve head

III. Contraindications

IV. Precautions

  1. Increased tension with expanded Retrobulbar Hematoma results in Optic Nerve ischemia
  2. Vision Loss may occur in as little as 60-100 minutes
  3. Do not delay Lateral Canthotomy when indicated and not contraindicated

V. Exam

  1. See Retrobulbar Hematoma
  2. Confirm no signs of Globe Rupture
  3. Visual Acuity before and after procedure
  4. Pupil response (evaluate for Afferent Pupillary Defect)
  5. Intraocular Pressure (before and after procedure)

VI. Preparation: Equipment

  1. Sterile gloves
  2. Suture kit
    1. Sterile Instruments: Hemostat (or needle driver), forceps with teeth, iris scissors
    2. Sterile drapes
  3. Anesthetic
    1. Topical Anesthetic
    2. Lidocaine 1-2% with Epinephrine in syringe with 30 gauze, 1 inch needle
  4. Miscellaneous
    1. Antiseptic (e.g. chlorhexidine)
    2. Saline irrigation fluid

VII. Technique

  1. Preparation
    1. Perform exam as above including Intraocular Pressure
    2. Patient supine with head of bed at 20-30 degrees
    3. Assistant stabilizes head and retracts Eyelids
  2. Lateral Canthus Incision
    1. Inject 1-2 ml into lateral canthus, away from globe along horizontal tract planned to cut
    2. Apply hemostat to clamp lateral canthus skin in horizontal line laterally 1-2 cm long and leave in place 1 minute
    3. With iris scissors, cut along clamped tissue to create a 1-2 cm horizontal incision from lateral canthus, laterally
    4. Avoid incision >2 cm (risk of Facial Nerve - temporal branch injury)
  3. Inferior Crus of Lateral Canthal ligament incision (inferior Cantholysis)
    1. Use forceps to retract the lateral lower Eyelid
    2. Identify the inferior crus of the lateral canthal ligament (tense like a guitar string)
    3. Cut the inferior crus with iris scissors directed away from globe, inferoposteriorly toward orbital rim
    4. Avoid injuring superior structures (lacrimal artery, lacrimal gland, levator muscle)
  4. Superior Crus of Lateral Canthal ligament incision (superior Cantholysis)
    1. Indicated after inferior Cantholysis if recheck Intraocular Pressure still > 40 mmHg
    2. Use forceps to retract the lateral upper Eyelid
    3. Identify the superior crus of the lateral canthal ligament (also tense like a guitar string)
    4. Cut the superior crus with iris scissors directed away from globe, superoposteriorly toward orbital rim
  5. Bandage
    1. Apply topical eye ointment (e.g. Erythromycin 5% ointment)
    2. Apply eye shield or cup over the affected eye

VIII. Disposition

  1. Emergent ophthalmology evaluation

IX. Resources

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Related Studies

Ontology: Lateral canthotomy (C0395154)

Concepts Therapeutic or Preventive Procedure (T061)
SnomedCT 231591006
English Lateral canthotomy, Lateral canthotomy (procedure)
Spanish cantotomía externa (procedimiento), cantotomía externa