Eye anatomy.



  • Suspected acute orbital compartment syndrome (OCS), plus one or more of the following:
    • Decreased visual acuity
    • IOP >40 or marked difference in globe compressibility by palpation
    • Proptosis
  • Secondary indications (subjective and nonspecific) - if only secondary indications are present, get emergent ophthalmology consult prior to performing canthotomy.
    • Afferent pupillary defect
    • Cherry red macula
    • Ophthalmoplegia
    • Nerve head pallor
    • Significant eye pain



  • Betadine prep
  • Sterile drape or towels
  • Lidocaine with epi
    • Syringe with 27-30ga needle
  • Normal saline for irrigation
  • Straight hemostat or needle driver
  • Iris or suture scissors
  • Forceps


Consider sedating patient for procedure, if time allows

  • Prep and drape the area (Irrigation with normal saline is acceptable prep given emergent nature of procedure)
  • Inject lidocaine with epinephrine into the lateral canthus directing the needle tip toward the lateral orbital rim (away from the globe)
  • Apply hemostat to the lateral canthus from the angle of the eye to the orbital rim and clamp shut for ~1 min. (provides relative devascularization as well as a landmark for the canthotomy)
  • Using scissors, incise the lateral canthus from the angle of the eyelid to the orbital rim (~1cm).
  • Retract the inferior lid and bluntly dissect tissue until the canthal tendon is identified.
  • Perform inferior cantholysis - cut the inferior crus of the lateral canthus tendon (point scissors infero-posteriorally toward the lateral orbital rim, avoiding the globe)
  • Recheck IOP → if still elevated, perform superior cantholysis - cut the superior crus of the canthal tendon (some experts recommend performing both inferior and superior cantholysis at the same time, prior to re-evaluating IOP)

Signs of successful procedure

  • improved visual acuity
  • resolution of afferent pupillary defect
  • decrease in IOP to <40 mm Hg[5]


  • Incomplete cantholysis
  • Iatrogenic globe or surrounding structure injury (rare)
  • Loss of adequate lower lid suspension
  • Bleeding
  • Infection

See Also

External Links


  1. 1.0 1.1 1.2 Rowh AD, Ufberg JW, Chan TC, et al. Lateral canthotomy and cantholysis: emergency management of orbital compartment syndrome. J Emerg Med. 2015 Mar;48(3):325-30.
  2. Mohammadi F, Rashan A, Psaltis A, et al. Intraocular Pressure Changes in Emergent Surgical Decompression of Orbital Compartment Syndrome. JAMA Otolaryngol Head Neck Surg. 2015 Jun 1;141(6):562-5.
  3. 3.0 3.1 McInnes G, Howes DW. Lateral canthotomy and cantholysis: a simple, vision-saving procedure. CJEM. 2002 Jan;4(1):49-52.
  4. Ballard SR, Enzenauer RW, O'Donnell T, et al. Emergency lateral canthotomy and cantholysis: a simple procedure to preserve vision from sight threatening orbital hemorrhage. J Spec Oper Med. 2009 Summer;9(3):26-32.
  5. Scofi J. Lateral canthotomy. In: Shah K, Mason C, eds. Essential Emergency Procedures. 2nd ed. Philadelphia, PA: Wolters Kluwer; 2015:(Ch) 17.