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Orbit: Foreign Body

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Let's continue with some of the

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nuances of ocular injury.

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Remember that globe rupture pertains to both

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the anterior chamber as well as the vitreous.

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So a shallow anterior chamber is also

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an indicative of globe rupture.

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Don't just look at the vitreous.

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In this particular case,

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we have a patient who has anterior chamber hyphema,

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anterior chamber rupture,

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compared the depth here with the depth here,

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compared the density here,

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lower density than the one that has blood

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products in it. But in this case,

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the patient does have vitreous rupture.

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This is likely because of the shape and

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the contraction of the vitreous.

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This is likely to be something that

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people refer to as ocular hypotony,

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and that is to suggest that there is decreased pressure

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within the vitreous chamber, and that's why

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it's looking a little bit like a flat tire.

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So ocular hypotony is the term we use.

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And you notice also on this blow up view

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that the angulation of the lens

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of the eye suggests that there

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has been lens dislocation.

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When we refer to open globe,

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we're talking about a communication of usually

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the anterior chamber structures with the outside

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world, often with a perforating injury.

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So an open globe is something that is treated

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immediately because of the risk of infection

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to the globe, leading to endophthalmitis.

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So this is another example of a patient on the left

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side where you see that there is a laceration going

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through the eyelid and the subcutaneous tissue

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which communicates with the left globe.

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There is hemorrhage here and we can see

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that the hemorrhage is in the vitreous,

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but the hemorrhage also is seen

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in the anterior chamber.

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We notice that the lens is dislocated

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and angulated and irregular.

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So traumatic cataract with lens dislocation,

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anterior hyphema, as well as blood

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products in the vitreous.

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And this lens dislocation is also nicely demonstrated on

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the coronal view where you see the

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normal lens looking right at you,

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and then this lens which appears

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to be looking laterally.

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So this is an open globe with traumatic dislocated

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lens with traumatic cataract. It's curious,

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but for the senescent cataract,

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the lens is actually more dense.

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You see it as sometimes calcified lens,

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but for a traumatic cataract,

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what you're seeing is edema in the lens,

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making it a less dense lens.

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Here we're going to continue looking at globes and

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a couple of important points. As part of the globe

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evaluation, you also want to look for foreign bodies.

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Why? Well, foreign bodies, they want

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to remove and make sure that

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it's not a source of infection.

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But also these foreign bodies can lead to injury to

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the globe and endophthalmitis in and of itself.

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Here we have a patient whose lenses

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disrupted. There's anterior chamber

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hyphema. You see that there is vitreous rupture, as well.

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The vitreous has hemorrhage within it.

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I don't think that this is a retinal detachment.

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It's the wrong shape,

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even though it does go to the the optic nerve.

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And here you can see that the vitreous has

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collapsed in in the ocular hypotony.

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This is an image of the eye showing an open globe with

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a full thickness corneal laceration.

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And the iris,

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which is the colored portion of your eye, can

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be seen extending into the pupil, right?

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So this is iris prolapse into

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the dark part of the eye,

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the pupil of the eye, due to the full

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thickness corneal laceration.

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This is a picture from radiographics.

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A little bit more about ocular trauma.

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Sometimes the patient has been whacked in the face

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with a piece of wood or a piece of wood during some

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repair that was being done for

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home building or whatnot.

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A little piece of wood will fly off from either a sander

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or from a drill and you have a wooded piece in the eye.

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Interestingly,

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non leaded wood,

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particularly the balsa wood and the light woods,

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appear as a very low density structure within the globe.

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Metal, obviously, is going to be as you can see with this

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green arrow, that's a piece of metal in the eye.

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It's different than wood,

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which again is lower density.

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Now, if it's leaded wood or leaded glass,

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it's going to appear as a hyperdense structure.

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If it's a lightwood or balsa wood,

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it's going to appear as a low density structure.

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So you have to be careful not to call this air.

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This is actually more dense than air,

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but less dense often than fat.

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So these are examples of foreign bodies

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in the globe that you want to look for.

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Notice here, the anterior chamber,

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very, very shallow compared to the anterior

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chamber on the left side.

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So this patient has anterior chamber rupture, and

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here we have blood in the anterior chamber,

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traumatic cataract.

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I think by now you've gotten sort of the

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message with regard to ocular trauma.

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Notice that behind the globes there is no retrobulbar

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hematoma or injury to the extraocular

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muscles or the optic nerves.

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Let's look at the detachments

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that I mentioned previously.

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We saw that on case two that the patient

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had a choroidal detachment

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medially and a retinal detachment laterally.

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Remember that the choroid, which is the pink tissue,

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goes all the way up to the lens and

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communicates and is part of the uveal tract

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with the iris and the ciliary apparatus.

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The retina stops at 10 o'clock and 2 o'clock

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at the oro serrata, and therefore,

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when you have a retinal detachment,

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it will stop at the oro serrata, right here at 10 o'clock,

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as seen in this diagram.

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Let's look at the cases.

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Here's there's a CT scan, here's an MRI scan.

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As we see here,

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we have a collection which is going all the way

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up to the anterior portion of the globe,

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and therefore it must be a choroidal detachment

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going that far anteriorly.

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Contrast that with this example.

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Here we have a patient who has a blood

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collection stopping at 10 o'clock and 2 o'clock .

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This is clearly a retinal detachment.

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It does not go all the way up to the lens of the eye,

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nor the ciliary apparatus.

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So these are classic appearance of choroidal

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detachments and retinal detachments. Unfortunately,

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when the globe gets ruptured,

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it often doesn't follow the textbooks.

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And sometimes you'll see what appear to be mixed

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collections, that some will follow one direction,

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some will follow another direction,

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some will extend anterior,

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some will extend not that far posterior.

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Most commonly,

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we say that the retinal detachment

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should begin at the optic nerve.

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Here you have a choroidal detachment doing the same.

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Most choroidal detachments will start

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at the vascular structures here,

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where the choroidal vessels come in and

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not be just centered at the optic nerve.

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Again, these are the lessons that are taught,

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but you're going to have to go with the

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flow sometimes with ocular injury.

Report

Faculty

David M Yousem, MD, MBA

Professor of Radiology, Vice Chairman and Associate Dean

Johns Hopkins University

Tags

Trauma

Orbit

Neuroradiology

Head and Neck

Emergency

CT

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