Managing Serious Cases of Ocular Trauma

Ocular trauma, although not an everyday encounter for many ophthalmologists, is a serious problem for our health system and economy.
In general, the more serious types of ocular trauma—such as ruptured globes and corneal lacerations requiring surgical reconstruction—are less frequently seen by most ophthalmologists.

Initial Presentation

When a patient who has suffered ocular trauma is first seen, the initial objective is to determine the nature and extent of the injury.

The first two actions to take when encountering a patient who has undergone ocular trauma are to make sure the patient is systemically stable and to get a history of the incident. 

Once you’ve made a global or systemic assessment and taken a history of the circumstances surrounding the injury, the examination of the injured begins.

Here is a list a number of key steps taken during examination:

• Checking visual acuity: This is the first order of business in the examination. Whether the patient has light perception or no light perception is very important with respect to prognosis, especially if the globe turns out to be open.
• Determine what is injured:When faced with a seriously traumatized anterior segment, we look for answers to several key questions. What exactly is injured? How deep does the injury go? What structures are involved? What tools will we need to accomplish the repair?

It’s important to do a complete eight-point ophthalmic evaluation. One key issue is whether there are intraocular injuries. If we can see through the cornea and there’s nothing in the anterior chamber and we can do a complete examination of the angle, iris, lens, vitreous and the posterior segment with the slit lamp and an indirect ophthalmoscope, we can be pretty sure there’s no occult damage. On the other hand, if the patient has a corneal laceration and we are not sure whether a foreign object entered the eye, or the eye is full of blood obscuring our view, we’ll need to do a CT scan.

• Determine whether or not the globe has been ruptured. Sometimes a ruptured globe is fairly obvious because the globe is misshapen or contents are extruding. However, a rupture in the globe can also be fairly subtle, so we need to check for other clinical signs that suggest that the eye is open. Such signs would include the IOP in the traumatized eye being significantly lower than the fellow eye; if the pupil is a different size from the other eye or is misshapen in some way, suggesting that the iris may be plugging a peripheral wound; if the anterior chamber is shallower or deeper than the fellow eye; and if there is significant chemosis—usually 360 degrees and usually hemorrhagic—suggesting that there may be bleeding through a scleral rupture.

Management is entirely different depending on whether or not the globe is ruptured. Closed-globe injuries usually involve blunt force to the face or eye. If the globe is closed, we follow an algorithm of checking to see what the injuries are. Are there any associated injuries such as orbital fractures or lacerations that need attention? Does the patient require antibiotics? This may be the case if there’s an orbital fracture. Does the eye have a hyphaema? Of course, we also want to examine the retina to make sure there’s no obvious retinal tear or detachment. If the eye has a traumatic cataract that blocks the view, a gentle ultrasound through closed lids can help to evaluate for retinal detachment or tear. It’s also important to look for any sign of traumatic optic neuropathy, which may manifest as acute swelling or haemorrhaging within the optic nerve.

An open globe injury involving a full-thickness wound, in either the cornea or sclera or both, is an emergency that requires prompt evaluation and may require surgical wound closure. If we suspect a rupture, we protect the eye from any pressure that could cause further extrusion of intraocular contents. A hard shield is placed on the eye, the patient is kept upright and he is told not to rub the eye. Also, we make sure the patient doesn’t consume any food or fluids in case surgery has to be done immediately. We confirm that the patient is up to date with his tetanus shots. Then, get the patient to the Operation Theatre as promptly as possible.

Urgent Orbital Concerns

We look for six types of injury when faced with ocular trauma. In order of urgency, these are: injury to the globe itself; compartment syndrome; optic nerve injury; bony injury; foreign bodies in the orbit; and injury to the eyelids. 

• Compartment syndrome.We look for signs of compartment syndrome, which refers to a sudden rise in pressure in the orbital tissues. The orbit is a closed space, and compartment syndrome can arise if anything accumulates within that space—pus produced by an infection, sudden bleeding inside the orbit, or air trapped inside the orbit. The resulting increase in pressure can damage the optic nerve or raise pressure inside the eye, which can lead to interruption in the blood supply to the eye and loss of vision.

Signs of compartment syndrome include the eye being prominent, i.e., pushed forward; tense eyelids; and/or restricted globe movement. We can also feel tension if we gently press on the globe. It’s important to look for these signs because compartment syndrome can cause permanent vision loss within half an hour if the pressure is high enough—but it’s reversible in many cases if you take quick action.

If we believe we are dealing with acute compartment syndrome, we perform a canthotomy and inferior cantholysis in the outdoor. A CT scan is arranged subsequently to determine what the underlying cause of the compartment syndrome was so that any need for draining can be addressed.

• Optic nerve compression.The third thing we need to look for is optic nerve compression, or traumatic optic neuropathy, an anatomical disruption of optic nerve fibres that can be caused by penetrating orbital trauma, bone fragments in the optic canal or hematomas in the nerve sheath.
  
  

  Less-Urgent Orbital Concerns

The remaining items on the list—bony injuries, foreign bodies in the orbit and injury to the eyelids—can be observed for several days before taking action.
• Bony injuries. The bony fractures within the orbit usually occur in the floor of the orbit or the medial wall. Common clinical signs of a blowout fracture include a history of blunt trauma to the eye; an eye that is enophthalmic (appearing sunken); numbness in the cheek (because the nerve that supplies sensation to the cheek runs through the floor of the orbit where the fracture occurs); and an eye that doesn’t elevate upwards or downwards well, leading to binocular double vision (because a muscle is entrapped in a bone fragment). A blowout fracture is typically confirmed with a CT scan.

• Foreign body in the orbit.Suspicion of this usually arises because of the circumstances surrounding the injury. For example, if the patient was in a car accident involving broken glass or was hit with a beer bottle, glass fragments could be embedded in the orbit. We should be especially suspicious if there are perforating wounds through the eyelids or globe. A CT scan or MRI can help to rule out the presence of a foreign object in the orbit.
• Lid injury.The last thing on the list is eyelid injuries. In most instances, as long as the eye is kept moist and protected, an eyelid injury can be repaired several days later.

In the Hospital

When a patient’s wounds require going to the hospital for immediate surgery, we need to do the following

• An Intravenous Drip is started.Once the patient is in the hospital, an IV is started The patient may be started on prophylactic intravenous antibiotics. Some type of anti-emetic can be given intravenously, along with something for pain control.
• Any needed ancillary studies are done.Generally, that means a CT scan or X-ray. We’ll do blood studies if we have a patient with a hyphaema and we’re looking for sickle cell anaemia and also to ascertain other parameters before surgery.

Once surgery has begun:

• Manage prolapsed tissue.If the prolapsed tissue consists of vitreous or lens fragments, we cut them off at the surface of the wound.
  
  • Close the eye.The primary concern here is to restore normal anatomy. It’s not enough just to get the eye closed and watertight, if we don’t get the anatomy right, we’re not going to restore function. 
  The goal is to explore the extent of the wound and then close it with as little collateral damage as possible.

Not every type of internal damage requires urgent treatment. It needs to be appreciated that most lens injuries, even a ruptured lens, do not constitute an emergency. We can manage an intraocular ruptured lens with topical corticosteroids for days or weeks while we assess the patient and optimize conditions for the second procedure. Certainly a dislocated lens can be managed later, and the same is true for the iris. As long as we put the iris back inside the eye when we close it, we can safely let the eye heal a little before attempting follow-up surgery—assuming we’re monitoring the patient during the waiting period. A minimal cataract shouldn’t be operated on at all until it gets bad enough to obscure vision and justify surgery.

Repairing Internal Damage

Usually, surgical repair of posterior segment injuries is done in two separate operations. The first operation, done immediately, aims to close the ruptured globe; the second, often done after a waiting period of a week or more, aims to repair the damage inside the eye.

Generally, unless there’s an infection or a foreign body, the second operation is not done for seven to 10 days. This allows the eye to heal a little bit and lets some of the inflammation and congestion die down. It also allows the vitreous to separate from the retinal surface so that a vitrectomy, if necessary, will be easier to perform. That’s helpful because in many cases trauma patients are young, making vitrectomy more challenging because the vitreous is very adherent to the retina. Waiting a week also allows any blood in the eye to ‘soften’ the vitreoretinal interface, helping to make the vitreous easier to remove completely.

When it’s time to do the internal reconstruction, it’s important to choose the best access path. In most cases, we would not enter the eye through the wound. We need to plan our entrance into the eye so that it matches the patient’s clinical condition and gives us the most flexibility, whether you need to perform simple cataract surgery, repair the iris or retrieve a foreign body that we couldn’t visualize at the time of primary surgery.

Long-term Follow-up

Once a patient has undergone eye trauma, the likelihood of future problems increases dramatically. When an eye has been subjected to trauma, monitor the patient over time for issues such as angle recession that could lead to chronic glaucoma. These patients should have a dilated fundus exam at appropriate intervals. Once a foreign body has been removed, that shouldn’t be a problem, but it’s always possible that a foreign body could be embedded. So if one of these patients presents later with an acute problem, remember that it could be a delayed consequence of the old injury.

Trauma patients need to be followed throughout the remainder of life, for two reasons. First, these patients are at increased risk for ocular complications, including angle-recession glaucoma, cataract and a peripheral retinal tear as a result of their injuries. The long-term prognosis following rupture of the globe depends in part on the location of the injury. If the injury is restricted to the anterior segment but not in the visual axis, the patient may retain good vision; he may have a little astigmatism, but otherwise should do well. If the corneal wound goes through the visual axis and it’s severe, the patient may eventually need a corneal transplant in order to get central vision back. If it’s a scleral wound, there’s a high risk of retinal detachment because of vitreous loss and incarceration causing traction on the retina. Patients in the latter situation should be evaluated promptly by a vitreoretinal surgeon once the immediate crisis is managed.

Past trauma patients are at greater-than-average risk for further injury. One of the highest risk factors for open-globe injury was having had a previous open-globe injury! It seems that these are high-risk individuals indulging in high-risk behaviour.

Late complications from earlier trauma are always a possibility. Last but not least, we advise any trauma patient to take extra steps to protect the good eye if one eye has been injured.