Upcoming Events
Log In
Pricing
Free Trial

Case 1 - Ocular Injury/Globe Anatomy

HIDE
PrevNext

0:01

When we think about ocular injury,

0:03

we have to know a little bit about the anatomy of the globe.

0:07

So, ocular injury, we're referring to the globe. And we like

0:11

to think of the globe in terms of these various segments of the globe.

0:15

We talked initially about the anterior

0:17

segment, which includes the anterior, the anterior chamber,

0:20

the lens and the uveal body.

0:22

And we'll talk a little bit about

0:23

the anatomy of the uveal body.

0:25

Then we have the posterior chamber.

0:26

Suffice it to say that this is such a small area of the globe that we actually

0:31

don't see very much trauma to the posterior chamber.

0:35

The large area behind the lens is actually the vitreous.

0:38

And within the vitreous, we also look at the vitreous membranes

0:42

of which the chloroid and the retina are most important.

0:45

The sclera is the ocular membrane that is on the outermost portion of the globe.

0:51

So here is a diagram of a globe, and I will

0:56

point out what we talked about initially, which is the surface of the globe,

1:02

in front of the lens, is the cornea. You see labeled here.

1:06

You see that there is an anterior chamber,

1:11

which is labeled here. Anterior chamber just behind the cornea

1:16

and in front of the lens.

1:18

The posterior chamber, which, as I said, is a very small area that we really are

1:23

unable to discern pathology in, is labeled here.

1:28

It's behind the anterior chamber, obviously, and in front of the vitreous,

1:32

and it is in close approximation to the lens.

1:36

I talked about the uveal tract, and the uveal tract includes the ciliary

1:42

body with the ciliary muscle, as well as portions of the choroid.

1:47

The choroid, as you can see here, is labeled in red.

1:51

And it goes all the way up to communicate

1:55

with that ciliary apparatus at the uveal tract.

2:00

So if we follow the choroid all the way

2:03

back, we can see it goes all the way back to the insertion site of the optic nerve.

2:09

Let's look at the membrane that is

2:11

superficial to the choroid, that is the retina.

2:14

So the retina is seen as this yellowish material, which stops at this juncture.

2:22

When we look at it on the axial scan, it's usually at 10 o'clock and 2 o'clock.

2:26

This will be 2 o'clock, this would be 10 o'clock.

2:28

And the area where it stops is known as the ora serrata.

2:33

So the retina does not go up as far as

2:36

the uveal tract, the ciliary apparatus, whereas the choroid does.

2:42

And that's going to be helpful to us

2:44

in separating choroidal detachments from retinal detachments.

2:48

And then finally, we have the outermost

2:51

covering of the globe, and that is the sclera.

2:55

And we could sort of follow that all

2:57

the way up until it communicates with the cornea.

3:00

And again, here is the sclera over here.

3:03

And we saw a little area of scleral injury on the first case that was shown.

3:09

So here is the junction of the optic nerve

3:12

with the posterior aspect of the globe and the communication with the retina.

3:16

And this area here is usually referred to as the papilla.

3:20

And we have this little hyaloid canal, which is obliterated with maturation.

3:25

So looking at this diagrammatically. Again, we see the choroid as it continues

3:31

into the ciliary body, and the retina, which stops beforehand.

3:38

And I mentioned the uveal track

3:40

which consists of the iris, which is the colored portion

3:43

of the eyeball, the ciliary body and the choroid.

3:48

This is another example of ocular injury.

3:51

And once again on the right side this time, which might imply a left handed

3:56

person who is hitting the person in the eye with the fist.

3:59

Here we see the soft tissues lying superficially.

4:02

We see the outline of the sclera leading to the cornea.

4:06

We see that the anterior chamber on the affected eye is of higher density

4:12

than the anterior chamber on the unaffected eye.

4:15

We see that the depth of the anterior chamber on the left side is greater than

4:20

the depth of the anterior chamber on the right side.

4:24

So there is indeed anterior chamber globe rupture.

4:27

And then we see this unusual appearance.

4:30

It's almost a right angle here to the lens, which has also been traumatized.

4:34

The lens is less dense than the lens on the left side.

4:38

Again, a traumatic cataract with lens

4:42

rupture, anterior chamber hyphema, anterior chamber rupture.

4:47

And the vitreous looks just fine.

4:50

So when we think about the location

4:53

of blood, blood in the anterior chamber, you'll hear this quite frequently

4:57

from the ophthalmologist, is called anterior hyphema.

5:00

It'll be labeled on the ophthalmology note as A.H.

5:04

Posterior chamber blood is not in the vitreous, it's in the posterior chamber.

5:08

Let's go back to this. Here's this little area known as the posterior chamber.

5:12

We usually don't discern blood

5:14

in that location, but they may refer to a posterior hyphema.

5:18

Hemorrhage in the vitreous is called vitreous hemorrhage, obviously,

5:22

and that's in the big part of the globe behind the lens.

5:25

And then we can talk about the various types of detachments of the membranes.

5:29

And the two most common are coroidal detachment and retinal detachment.

Report

Faculty

David M Yousem, MD, MBA

Professor of Radiology, Vice Chairman and Associate Dean

Johns Hopkins University

Tags

Neuroradiology

Head and Neck

Emergency

© 2024 Medality. All Rights Reserved.

Contact UsTerms of UsePrivacy Policy