0:01

Well, I've done a lengthy segment on ocular imaging,

0:05

and that's because I think that the individuals who

0:09

are interpreting orbital CT scans in the trauma

0:12

section are usually focused on fractures

0:15

and not on the injury to the soft

0:18

tissues, and in particular the injury to the anterior

0:21

segment where you have anterior hyphemas and open

0:24

globes and globe rupture of the anterior chamber.

0:29

So, we've done a relatively lengthy section on that.

0:32

Now, let's look at non-ocular orbital

0:35

trauma. And in that situation,

0:37

we really are focusing on fractures and

0:40

one of the complications of fractures,

0:42

which is entrapment.

0:44

And then, we also will talk a little bit about

0:46

retrobulbar hematoma and hematomas outside

0:50

the muscle cone in the extraconal space.

0:53

I want to use these diagrams to introduce the

0:55

topic. So, when we're talking about fractures,

1:00

sometimes those fractures can lead to entrapment,

1:04

which leads to restriction of

1:08

orbital or ocular motion.

1:11

So you see in the bottom left image, someone

1:16

who's been told to look upward

1:19

outwardly and to the right side,

1:22

and you notice that this globe is not moving.

1:25

The left globe is turning,

1:29

but the right is not moving.

1:31

And that is what we're talking

1:32

about by entrapment.

1:33

And this is demonstrated in the diagram above,

1:37

where we have the tendon has been trapped

1:43

and is fixed at the site of the fracture.

1:46

You see a small fracture here and there is no

1:50

movement of this globe as it's not able to turn

1:55

from right to left. It's kind of fixed in position.

1:57

So that's what we're referring

1:58

to with entrapment.

2:00

With regard to the orbital floor fractures,

2:03

which we're seeing here,

2:04

the typical muscle that is herniating through the

2:08

fracture segment is the inferior rectus muscle.

2:11

And with the inferior rectus muscle,

2:12

what happens is,

2:13

as you can see on the involved eye,

2:15

that the eye is not able to look up because the

2:19

inferior rectus muscle is sort of fixed in position

2:23

and not allowing that globe to rotate upward

2:26

when you tell the person to look up.

2:28

So obviously, the evaluation of entrapment is clinical.

2:34

We can suggest that the person likely has

2:37

entrapment when we see muscular or fat

2:39

herniation through a fracture fragment.

2:42

But remember that this is a

2:43

clinical evaluation overall.

Case 2 - Non-Ocular Orbital Trauma

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