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Orbital Trauma

September 7, 2019


Hello, this is Dr. Evans. We’re going to be talking about orbital and ocular trauma today. When assessing anybody in a trauma scenario, even if it looks relatively benign or relatively isolated to the eye, the first thing you really want to consider are any life- or limb-threatening injuries. You really want to go through your kind of standard ABCs, check the airway and make sure they’re breathing well, and look at their circulation, assess for any limb disability, any neurologic deficits. Once the patient’s stability is assessed and everything looks satisfactory from that standpoint, an ocular assessment may go ahead and proceed with a complete eye evaluation. So for the ocular assessment, a couple of things that need to be checked– visual acuity is really important. You should get that in each eye. You should do an external exam looking at the lids and the periorbital structures. Look at the extraocular muscles, and just do that by lateral gaze, medial gaze, gazing up, gazing down, looking at accommodation. Pupil should also be assessed. Just with the pen light’s usually easiest, or if you have an opthalmoscope with you– which hopefully you do– look at the anterior segment and the posterior segments with the opthalmoscope It’s nice to actually have a slit lamp when you’re doing this. The intraocular pressures should also be measured in each eye with a Tono-pen. Normal pressures run about 10 to 20 millimeters of mercury. If it’s a very low pressure, it’s concerning for a globe penetration or an open globe injury. And then, we’ll talk about imaging as well for assessment of the eye. So just some basic eye anatomy– these are most of the things that you need to know from the external standpoint. The really big things you want to focus on are the lid and the lid margins, or really the medial apparatus, really including the medial canthus, which is the opening to the drainage end of the lacrimal duct. Injuries in this area are concerning for lacrimal duct injuries and should be further worked up for that. Other external eye anatomy pieces that are important– really, the tarsal plate is something that I like to think of as something that gives support to the lid structures and should be evaluated, as well. So the actual globe itself– this is a pretty detailed diagram, as well. It gives a nice breakdown of the external globe all the way through the anterior chamber and into the posterior chamber. Anterior chamber is capped on the anterior section by the cornea. And then, there’s that space just beneath the cornea that extends all the way to the iris. And that space right in there is known as the anterior chamber, which is where you’ll see a hypopyon. You can see a hyphema there when you’re examining the eye. Just posterior to the iris is the lens, which you can see, again, just posterior to the iris, a budding up against the pupil. The zonules and the ciliary body are what kind of hold the lens in place and actually stretch it out and let it relax when accommodating the eye. Behind that is the posterior chamber where you’re really going to want to visualize for retinal detachments, for vitreous hemorrhage, and to see along the posterior edge of the posterior chamber where you can see the actual optic disk and the macula, which are very important to evaluate in the setting of ocular trauma. So, some specific injuries and management, and the way we’re going to look at these, as well. Subconjunctival hemorrhage is very common. A lot of times, you’ll see that with an increase in intraocular pressure. You actually rupture a blood vessel. And you’ll notice that as a little red or dark red spot actually in the sclera, so in the whites of the eye. It’s often associated with a big valsalva maneuver. Sometimes it will even happen spontaneously when someone is just rubbing their eye. For these, no treatment is necessary. They’ll often resolve in a couple of weeks. Sometimes it takes a little bit longer. But although they’re generally somewhat distressing to the patient, they’re not dangerous. Eyelid lacerations and periorbital injury– these are things where you want to really rule out globe rupture if you have any suspicion for it. Intracranial injury, although relatively uncommon, if the mechanism is right you certainly want to be on the lookout for that. So simple eyelid lacerations that don’t involve underlying structures, a.k.a the underlying fat, the tarsal plates, those can be repaired without a specialist. However, if the fat or underlying structures are protruding through the laceration, you generally want a specialist to repair, and for that to be repaired under a microscope. It’s not something you probably would want to take up on your own without specialized equipment unless you’re forced to. If the laceration is near the medial canthus, again, that’s where the nasolacrimal apparatus or the nasolacrimal duct drains down. And if that occludes, it can have some long-term complications– a lot of tearing, poor drainage, and running out straight out of the eye over the inferior lid margin. So you certainly want to ensure that that is patent. Orbital and facial fractures– so when there is a periorbital injury, or even when there is orbital injury as well, you’ll have a situation where a big, blunt object kind of strikes the orbital rim. A lot of times, these are referred to as blowout fractures. And they’re often on the medial or inferior walls of the orbit. Generally speaking, these can be managed conservatively, but you do want to image them if you suspect fracture there to make of a couple of things. One is that there’s no evidence of a retrobulbar hematoma. Make sure there’s no evidence of a superior wall injury, which is concerning for actual intracranial injury, just because that superior wall abuts the cranial vault. Usually, spiral CT is the imaging tests a choice that we use. Antibiotics are somewhat controversial, but the general consensus is to cover with anti-staph, anti-strep antibiotics. And again, these don’t usually require surgical intervention unless potentially if there is a intracranial injury, or if there’s extraocular muscle entrapment within the fracture site. So one thing that you do want to check, as well, with orbital and facial fractures are the extraocular muscles. Make sure there’s no pain in lateral or superior gaze. Burns to the eye– we generally break down chemical burns into alkali versus acid burns. Alkali are usually more severe due to the process of liquefaction necrosis. It just keeps on damaging the eye as layers are burned and injured. Acid burns are a little less severe, just because coagulation necrosis occurs, forming a barrier that prevents deeper damage. With both of these, you want to manage with copious irrigation. I usually irrigate for 20 minutes at a time. The Morgan lens is the easiest way to do this– just little cups that you can infuse saline straight over. And you want to check the pH about every 20 minutes. Once the pH is between seven and 7.4, then you can stop. You want to really recheck it every 15 minutes or so for the first hour just to make sure that you’re staying within that acceptable range. Another common type of burn is UV keratitis, which is from the sun. Some people get it from welding. People get it from tanning salons. This is usually managed conservatively with NSAIDS. Analgesics work just fine, too. Corneal and conjunctival injuries– corneal abrasions are very common. People feel like they have a foreign body in their eye. And the way you look for this is with a fluorescein stain and a cobalt light. You’ll just put a couple drops of fluorescein on the actual globe, shine a cobalt light on it, and you can see the abrasion just light up. You definitely want to look to see if there is a foreign body. If it’s beneath the lid and it’s repeatedly scratching the eye, you’ll see the characteristic, vertically-oriented scratch marks just right on the actual cornea. If the patient does wear eye contact, they’re at a much higher risk for pseudomonal infection with actual corneal ulceration. So that should definitely be of concern. You should perform Seidel’s test, which is really just looking at the fluorescein that you put on the eye, and just look to see if it looks like there’s a vitreous leak beneath it, and just watch for that fluorescein seeing almost running away like a little river or a little stream of fluorescein in the light. If that fluorescein test– or Seidel’s test, I should say– is positive, then globe penetration is really what you’re looking at. If it’s severe, or if it’s obvious, you’ll actually see a tear-shaped pupil that actually points towards the globe rupture. And that’s because the actual iris gets pulled through that site of injury, which you can see on this slide down at the bottom. Traumatic iritis is very common after eye trauma. It’s more of a symptomatic diagnosis. At times, it’s hard to find a real objective physical science aside from the cell and flare seen in the anterior chamber. The patient will complain of photophobia, maybe have some blurred vision, certainly have some tearing. When you look at the anterior chamber with a slit lamp, you’ll just see white cells– just a sign of an inflammation in the anterior chamber. You want to manage this with a cycloplegic and have them seen again in 36 hours by an ophthalmologist. Hyphema can occur with orbital injuries. And that’s really just the blood collection in the anterior chamber. For them, you just really want to keep them at 30 degrees up in the bed and have your ophthalmologist come and take a look. Sometimes they’re managed conservatively, sometimes not, usually depending on the actual size of the hyphema. Lens dislocation can occur with orbital trauma. The pathognomonic complaint from the patient is that they have binocular diplopia, which is, when they’re looking out of one eye, they’ll actually see double vision from that, and that’s just a displacement of the lens. And this is more common when you have a connective tissue disease– Marfan Syndrome in particular is kind of the classic with that. Posterior segment injuries and posterior chamber injuries– these include injuries to the choroid, the retina, the vitreous, and optic nerve– present with blurred vision, pain in the back of the eye, flashes of light, curtain of darkness, sometimes it is described. It’s usually best identified with indirect fundoscopy by your ophthalmologist, although you can certainly see it on your opthalmoscope exam if you have one at the bedside. And you can actually see this on ultrasound, too, with a high-frequency probe, especially a retinal detachment. Retrobulbar hematoma– this is definitely a time-sensitive emergent condition. A patient will present with a proptotic eye, have some blurry vision with some pain. And this actually requires a release of the globe, where you’ll perform a lateral canthotomy. And that’s to release the pressure behind the globe, which will decompress the optic nerve and the vessels that are supplying the globe. The retina only has about 90 minutes of ischemic time before it undergoes permanent damage. That’s really 90 minutes at tops, so this is a pretty emergent intervention that you can do. It’s not without its complications, of course, but if you’re forced to do, it’s something you should be familiar with. Endopthalmitis is something that is a delayed presentation after trauma. It’s usually just the result of a retained foreign body. You will have an inflammatory reaction that results in a hypopyon, which is just a white cell layering, similar to the hyphema we saw before, except this is white in color– just white cells– really almost pus, per se, that layers in the anterior chamber. And you should certainly seek ophthalmologist’s consultation for these for definitive management. All right, well, that pretty much wraps it up. So again, just a quick overview. Make sure there’s no life-threatening injuries when you’re first evaluating overall trauma. From there, external exam check, visual acuity in each eye, and then go through the anterior-posterior chamber, see what you see, and intervene accordingly. Thank you very much.

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