eye disorders
How To Do Lateral Canthotomy
Step by Step Description of Lateral Canthotomy
All preliminary steps should be done as quickly as possible, including rough Assessing Visual Acuity , inspection of the globe, and sometimes a simple cleaning and irrigation of the lateral canthus area. Place all your instruments on a tray near the head of the bed, so everything is within easy reach and you do not have to ask for assistance. Prepare the skin with an antiseptic agent such as povidone iodine orchlorhexidine; do not allow the antiseptic to enter the eye. Drape the area. Inject 1 or 2 mL of local anesthetic containingepinephrineinto the lateral canthal incision site. Use a needle driver or hemostat to crush the tissue from the lateral canthus to the rim of the orbit, for about 20 seconds to 2 minutes. Crushing this tissue helps minimize bleeding and makes it easier to see where to cut when there is extensive traumatic edema. Use iris scissors to cut from the lateral canthus to the rim of the orbit, about 1 to 2 cm (canthotomy). Cut the inferior and sometimes both crus of the lateral canthal ligament (cantholysis). Most experts recommend starting with the inferior crus. Lift the lateral portion of lower eyelid. With the scissors pointing away from the globe, identify and cut the inferior crus. “Strumming” with the scissors may help identify the inferior crus. If the tendon is still intact, you will feel a twanging like a plucked string. Next, some experts recommend routinely cutting the superior crus. Others recommend reassessing for relief of orbital compartment syndrome (OCS—eg, by measuring intraocular pressure) and cutting the superior crus only if OCS persists. To cut the superior crus, lift and expose the underside of the lateral upper eyelid. Check whether the superior crus tendon has been cut by strumming across it with the scissors. If the tendon is still intact, cut it. Cutting the tendon loosens the eyelid and relieves pressure on the eye even more. Procedure demonstrated by Matthew A. Stephens, MD, faculty. Walter A. Schrading, MD, FACEP, faculty supervisor. WellSpan York Hospital Emergency Medicine Residency Program York, PA. Cadaver specimens provided by Maryland State Anatomy Board, DHMH. Filmed on location at School of Medicine, Anatomical Services Division, Univ. of Maryland. 