Traumatic Eye Swelling

Subconjunctival and orbital emphysema with orbital floor fracture 

After sustaining an orbital blowout fracture, the patient blew his nose and tracked air into the orbit and under the conjunctival plane. Because of the left eye proptosis, marked conjunctival swelling, and fixed ocular motility, we considered performing a lateral canthotomy. The ophthalmologist opted to review a CT of the orbits first, given the absence of an afferent pupil defect, nearly preserved visual acuity, and borderline intraocular pressure. On visualizing subconjunctival emphysema on CT, the ophthalmologist performed a bedside conjunctival needle decompression with an 18-gauge needle, producing an immediate rush of air. The patient regained normal intraocular pressure, extraocular movements, and visual acuity.

Indications for lateral canthotomy include signs of retrobulbar hematoma with increased intraocular pressure (>40 mm Hg), relative afferent pupillary defect, decreased vision, proptosis, and decreased ocular motility.1, 2 Although lateral canthotomies can be sight-saving interventions, they can also result in significant periocular damage such as ectropion, ptosis (damage to the levator aponeurosis when cut too superiorly), damage to the lacrimal gland or lacrimal artery, globe injury, and cosmetic deformity.3 They are contraindicated in open globe injuries (enophthalmos, exposed uvea, or an irregularly shaped pupil). If emergency ophthalmology consultation had not been available for our patient, a lateral canthotomy may have been indicated. Prolonged increase in intraocular pressure can lead to optic nerve damage from ischemia similar to compartment syndromes in 1 to 2 hours if intraocular pressure approaches ophthalmic artery perfusion pressure.4 Emergency physicians should be familiar with this critical procedure and weigh the risks and benefits of its application.