Ocular Injury and Emergencies Around the Globe

Key points

  • Retrobulbar hemorrhage in the setting of orbital trauma can cause orbital compartment syndrome, which may result in irreversible vision loss. Immediate action through a lateral canthotomy and cantholysis is required.

  • Ocular examination should be performed by an ophthalmologist in any case of periocular trauma. If globe laceration is suspected, any manipulation of the area should be avoided until integrity of the globe has been confirmed or sufficiently restored.

  • Adequate knowledge of the anatomy and functional and dynamic behavior of the eyelids is paramount when performing repair of an eyelid laceration.

  • Repair of canalicular lacerations should be attempted in all cases within 48 hours by a surgeon experienced in lacrimal surgery.

Introduction

The orbital soft tissues include various important structures such as the eyelids, lacrimal drainage system, extraocular muscles, the optic nerve, and the globe. Although protected by the bony orbit, these structures are prone to traumatic injuries which, as discussed in this chapter, include orbital compartment syndrome, globe laceration, eyelid laceration, and damage to the lacrimal drainage system. It is paramount that such injury is timely recognized and adequately dealt with, and a thorough examination should therefore be performed by an ophthalmologist in any case of orbital trauma. However, because of the multidisciplinary nature of the orbital region, it is important that other physicians also are familiar with these injuries.

Retrobulbar hemorrhage and orbital compartment syndrome

Etiology and clinical assessment

The intraorbital structures are confined within a closed and rigid compartment consisting of the bony orbital walls and the orbital septa and eyelids ( Box 1 ). As such, there is little space to accommodate a sudden increase in orbital pressure. Orbital compartment syndrome (OCS) occurs when the intraorbital pressure exceeds the arterial perfusion pressure, resulting in ischemia and irreversible damage to the optic nerve and retina within 100 minutes. The most common cause of such an increase in orbital pressure is retrobulbar hemorrhage, as may occur in the setting of periocular trauma.

Box 1
Signs of orbital compartment syndrome

  • Progressive proptosis

  • Decreased visual acuity

  • Relative afferent pupillary defect (RAPD)

  • Concentric motility impairment

  • Pain

  • Increased intraocular pressure

  • Tight orbital tissues

  • Chemosis

  • Decreased retinal perfusion, as noted on fundoscopy

Treatment: lateral canthotomy and cantholysis

In line with the previously mentioned etiology, emergency treatment is directed at opening up the closed compartment. This is accomplished in the first place by performing a lateral canthotomy and cantholysis, a technique that any emergency physician or medical specialist involved in the orbital region should be familiar with. The canthal ligaments (sometimes referred to as tendons) are the structures that attach the eyelid tarsi to the bony orbit, with the lateral ligament being the most easily accessible. Releasing the eyelid from its attachment to the lateral orbital wall opens up the orbital compartment and allows for an anterior movement of the globe, thereby decreasing the intraorbital pressure. Sometimes the question is raised whether this anterior movement of the globe does not stretch the optic nerve, causing permanent damage as well. However, the length of the orbital part of the optic nerve is somewhat redundant, allowing for some degree of exophthalmos before the nerve fibers are put on stretch. Even more so, tensile forces on the optic nerve are far less harmful than ischemia.

Lateral canthotomy and cantholysis is performed as follows:

  • Canthotomy ( Fig. 1 A): Use scissors to make a cut in the lateral canthal angle, directed away from the globe, up to the lateral orbital rim. The cut is made through all layers of the lateral canthal angle at once: skin, orbicularis muscle, lateral canthal ligament, palpebral conjunctiva. Make sure not to cut the bulbar conjunctiva, as this may cause symblepharon. This first cut effectively divides the lateral canthal ligament into an inferior and superior limb.

    Fig. 1
    Technique for lateral canthotomy and inferior cantholysis. ( A ) Lateral canthotomy. ( B ) Dissection of a skin-muscle flap. ( C ) Inferior cantholysis.
  • Skin-muscle flap ( Fig. 1 B): By blunt dissection, you can now create a skin-muscle flap inferior to the lateral canthal angle.

  • Inferior cantholysis ( Fig. 1 C): When you raise the skin-muscle flap, the underlying inferior limb of the lateral canthal ligament is exposed, but often not clearly distinguishable. With tooth forceps, grasp the eyelid margin of the lower eyelid near the lateral canthal angle and pull the eyelid medially and anteriorly. By doing so, the inferior limb of the lateral canthal ligament is put on stretch. With the tip of the closed scissors you can now feel the inferior limb of the canthal ligament as a tight string. Open up the scissors around this string and cut it with your scissors directed directly inferior. Again, feel with your scissors for residual attachments and cut them. Repeat this until the cantholysis is completed and the eyelid is freely mobile. Note that the lateral canthal ligament is continuous with fibers from the orbital septum. Therefore, the cut may need to be extended to include the septum to acquire adequate mobility.

  • Superior cantholysis: If you feel that inferior cantholysis has yielded insufficient release of the compartment syndrome, superior cantholysis can be performed in a similar fashion. It is advisable to direct this cut superiorly as well as slightly laterally to avoid cutting into the lacrimal gland, which may cause brisk bleeding and can result in severe dry eye.

  • Repair of the lateral canthal angle: After approximately 2 weeks, the canthal angle can be closed; however, in most cases, repair is not necessary, as spontaneous granulation usually provides adequate results.

It should be noted that in the setting of an orbital fracture (mostly the floor or medial wall), the compartment may have been opened up sufficiently by the fracture itself and cantholysis may not be necessary. However, OCS still can occur if the periorbita remains intact. Conversely, if inferior and superior cantholysis have been performed without the desired effect, emergency orbital decompression, including opening of the periorbita, must be considered.

Orbital compartment syndrome and imaging

The indication for imaging in the context of OCS, as well as the precise indications to perform cantholysis, are source of debate. We advise the following rules of thumb:

  • Do not delay treatment awaiting radiological evaluation:The decision to perform inferior cantholysis should be made based on clinical signs, not solely on the findings of computed tomography (CT) imaging. Although a retrobulbar hemorrhage can be easily seen on CT imaging, the urgency of the situation dictates to act immediately when OCS is suspected, without delay for radiological evaluation. Conversely, a small retrobulbar hemorrhage that is noted on CT imaging without clinical manifestations of OCS may be left untreated.

  • When in doubt, make the cut: Remember that not performing a cantholysis when you should have done so, may result in permanent and profound loss of vision. On the other hand, an adequately executed, inferior cantholysis rarely causes permanent complaints after healing.

Trauma to the globe

Ocular examination

It is important to remember that damage to the intraocular structures can occur even in apparently mild cases of trauma, and thorough ocular examination should therefore be performed by an ophthalmologist in any case of periocular trauma. The first assessment, however, can be performed by the emergency physician ( Box 2 ). We believe that the ophthalmologist should be involved directly in the emergency room in any of the circumstances, as listed in Box 3 . In any other case, more detailed examination by an ophthalmologist can be performed within the next few days.

Box 2
Ocular assessment by emergency physician

  • Confirm integrity of the globe

  • Visual acuity

  • Red cap test

  • Confrontational visual field

  • Ocular Motility

  • Pupillary test, including RAPD

Box 3
Indications for ocular assessment by an ophthalmologist

  • Suspected intraorbital hemorrhage

  • Suspected globe laceration

  • Suspected extraocular muscle entrapment

  • Exophthalmos or tenting of the optic nerve

  • Eyelid and/or lacrimal lacerations

  • Decreased vision

  • Unconscious patients

Globe laceration

Laceration of the globe can occur in penetrating or blunt periocular trauma and accordingly should be ruled out in all cases of periocular trauma. Signs of globe laceration are listed in Box 4 .

Box 4
Signs of globe laceration

  • Prolapse of uvea, vitreous, or retina ( Fig. 2 )

  • Intraocular foreign body (as noted on biomicroscopy/fundoscopy or orbital imaging)

  • Orbital imaging suggestive of globe laceration

  • Leakage of intraocular fluids as demonstrated by a positive Seidel test

  • History of sharp periocular trauma

  • Eyelid laceration

  • Extensive subconjunctival hemorrhage

  • Peaked pupil (see Fig. 2 )

  • Shallow anterior chamber

  • Hypotony

Fig. 2
Small globe laceration at the level of the limbus. Note the peaked pupil pointing toward the location of the uveal prolapse.
( Courtesy of J. De Faber, MD, Rotterdam, The Netherlands.)

If a globe laceration is indeed suspected, the following should be initiated:

  • Place a protective shield (not a pressure bandage!)

  • Ask the ophthalmologist for urgent consultation

  • Make sure the patient is kept on a nil per os regimen

  • Provide with adequate systemic analgesics

  • Avoid any manipulation of the globe and eyelids:

    • Do not administer topical medication unless necessary

    • Provide with adequate sedatives in case of anxiety

    • Provide with adequate antiemetics, as vomiting may give increased pressure on the globe

    • If possible, postpone examination or treatment of other injuries until integrity of the globe has been confirmed or sufficiently restored by an ophthalmologist.

Other traumatic ocular injury

Although a detailed description is beyond the scope of this article, other complications of ocular trauma are listed in Box 5 .

Feb 28, 2021 | Posted by in Oral and Maxillofacial Surgery | Comments Off on Ocular Injury and Emergencies Around the Globe
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