0:00

This was a young woman who developed painful,

0:05

irritated left eye after an insect bite on the face.

0:11

As we scroll through these scans,

0:13

you note that they are performed with contrast

0:16

administration. For infectious inflammatory conditions,

0:20

we give intravenous contrast on the CT scans.

0:24

In this situation,

0:27

what we see with regard to the left eye is swelling of

0:31

the eyelid as well as swelling of the

0:35

sclera and cornea of the left eye.

0:40

And that cornea is somewhat irregular in its contour.

0:45

You also note that the patient has a fluid

0:48

collection superficial to the cornea.

0:54

This collection is seen as showing a border of contrast

1:00

enhancement as well as a small area

1:04

of edema within the collection.

1:07

Whenever we have air in an orbital collection,

1:10

we worry about polymicrobial disease and this is treated

1:14

much more aggressively than if it's a single staphylococcus

1:19

or staphylococcal epidymitis infection. In this case,

1:22

the inflammation remains anterior to the posterior

1:28

segment of the globe and it also remains

1:32

anterior to the orbital septum.

1:36

This would be termed preseptal cellulitis and the other

1:41

term that is used is periorbital cellulitis.

1:47

Periorbital cellulitis is distinguished from orbital

1:51

cellulitis or postseptal cellulitis depending

1:55

upon whether the orbital septum is involved.

1:59

The orbital septum is a dense,

2:01

fibrous tissue which inserts on the tarsal plates of the

2:05

eyelids and it prevents anterior infections from

2:10

infiltrating the retrobulbar space of the orbit.

2:16

So let's scroll these images and make sure that the

2:19

orbital fat is not involved in the intraconal space.

2:23

So as we look here, we have a nice,

2:26

clean optic nerve and the fat in the retrobulbar

2:30

compartment looks fine compared to the contralateral

2:34

side and there is no involvement

2:36

of the postseptal space.

2:39

So this patient we would characterize as having

2:42

periorbital cellulitis with a periorbital or lid abscess

2:49

for which the patient is likely to have intravenous

2:52

antibiotic therapy. Without the abscess,

2:56

one would simply have periorbital cellulitis.

3:00

Periorbital cellulitis is a diagnosis that is made in

3:04

the emergency room and is treated with oral antibiotics

3:07

as an outpatient that's to be contrasted with

3:11

orbital cellulitis. For orbital cellulitis,

3:14

the patient is generally admitted for at least 24 hours

3:18

of intravenous antibiotics because of the risk of

3:22

involvement of the optic nerve sheath complex

3:26

and potential infectious optic neuropathy.