Ophthamology: Ocular and Orbit Injuries Flashcards Preview

Clinical Neuro Exam 1 > Ophthamology: Ocular and Orbit Injuries > Flashcards

Flashcards in Ophthamology: Ocular and Orbit Injuries Deck (31):
1

What is the ultimate goal in treatment of an eye after traumatic injury?

Diagnose and protect a ruptured globe to protect extravasation of contents.

2

What is the immediate treatment for:
-flate anterior chamber, hyphema, blind eye, or obvious extravasation of globe contents?

Put a shield over the eye and get an ophtho consult.

3

What kind of traumatic injury causes a restriction in upward gaze.

Blowout fracture and entrapment with damage to extraocular muscles.

4

How long does corneal epithelium take to heal?

12-36 hours

5

Other than testing VA and using fluorescein dye to locate the scratch, what else should be done if a corneal abrasion is suspected?

Evert the upper lid to look for a foreign body.

6

What is the Seidel Test?

Test to look for a penetrating injury to the globe and leaking aqeuous humor.

-under white light the fluorescein dye appears green w/i an orange background

-under blue light the fluorescein dye appears green with a dark green background

7

What is the treatment for a corneal abrasion in a patient that wears contact lenses?

Fluoroquinolone or Tobramycin
(want to cover pseudomonas)

8

What is the treatment for a corneal abrasion in a patient that does not wear contact lenses?

Erythromycin Ophthalmic Ointment
-QID x 5 days
(Quater in Die = 4 times a day)

9

What causese the photophobia in iritis?

Ciliary muscle spasm. Can also lead to a consensual photophobia in opposite eye.

10

Corneal abrasions can present with an anterior chamber reaction. The ACR is performed with a slit lamp shined on the cornea and results in sparkes and flares of light. What accounts for the sparkles and what accounts for the flare?

Sparkles: suspended white blood cells
Flare: suspended protein (maybe the start of pus formation)

11

Treatment for iritis pain due to spasm of ciliary muscle.

Atropine: for 2 weeks potent cycloplegic
(cycloplegia is paralysis of the ciliary muscle)

NSAIDs: 3 days

12

What is the main cause of a traumatic hyphema?

Rupture Iris Root Vessel

13

What is the main cause of a spontaneous hyphema?

Patient with Sickle Cell Disease having a sickle cell attack

14

Describe the 0-IV grading of hyphema.

Based on how much of the anterior chamber is filled w/ blood

0 : only suspended RBCs viewed in anterior chamber reaction

I : less than 1/3 of the ant. chamber filled

II : 1/3 to 1/2 of ant. chamber filled

III : greater than 1/2 chamber filled

IV : eight ball (completely filled)

15

Why should you give an anti-emetic during treatment of patients with a hyphema?

Vomitting can cause rupture of more blood vessels in the eye and make the situation worse.

16

What can you give patients that have a hyphema to decrease IOP by dilating the Canal of Schlemm?

Timolol - a beta blocker that will prevent dilation of the pupil

17

What class of drugs should you not give a patient with a spontaneous hyphema and why should you not give these drugs?

If the hyphema is spontaneous, you usually suspect the patient has sickle cell disease.

Do NOT give carbonic anhydrase inhibitors because this will cause a drop in pH and further induce sickling of the cells.

18

What is the difference between a lens subluxation and lens dislocation?

Sublux: disruption of about 25% of zonular fibers, however, the lens is still in the pupillary aperture.

Dislocation: complete disruption of the zonular fibers and the lens is not in the pupillary aperture.

19

What two hereditary conditions predispose patients to have lens displacements?

1. Homocystinuria
2. Marfan Syndrome

20

What condition causes photopsia?

Photopsia is "seeing" flashing lights and floaters.

Occurs in retinal detachment with associated vitreous hemorrhage.

21

What causes the flashing lights and floaters in photopsia?

Flashing Lights: separation of posterior retinal mechanically stimulates the neural layer of the retina creating an electrical reaction due to release of phosphenes.

The floaters result from light reflecting off RBCs released from ruptured vessels.

22

What is the Shafer Sign?

Floating pigment in the vitreous humor that indicates retinal detachment.

23

If the macula is involved in a retinal detachment, how long does a physician have to perform treatment before the macula is irreversibly injuried.

3 days

24

What is the treatment (2 things) for a retrobulbar hemorrhage?

1. Timolol: beta blocker that opens the canal of schlemm to decrease IOP

2. Lateral Canthotomy: incision in the lateral part of the conjunctiva to further relieve pressure in the orbit

25

What is a blowout fracture?

Fracture in the orbital floor which includes the maxillary, palatine, and zygomatic bones. These bones "blow out" into the maxillary sinus. Affects the fat around the extra-ocular muscles which become stuck in the sinus (space created in the fractured bone) impairing movement of the eye: especially upward and lateral due to the inferior rectus and inferior oblique muscles being affected.

(The superior, lateral, and medial regions of the orbit can be fractured but are less common)

26

What are the two theories on a blowout fracture?

1. Buckling Theory: force hits the orbital rim which transmits to the orbital floor and causes the bones to fracture into the maxillary sinus.

2. Hydraulic Theory: force on the eyeball distorts it and the globe pushes on the orbital floor causing a fracture into the maxillary sinus.

27

What is the "tear drop" sign?

Orbital contents or fat herniating down into the maxillary sinus after a blowout fracture.

Viewed on coronal CT scan

28

What is the treatment for a bowout fracture?

Ice packs for 1-2 days. Consult plastic surgeon for repairs if muscles are entrapped.

If it is a superior blowout fracture: consult neurology for possible CNS involvement.

29

What is chemosis?

Conjunctival Swelling

30

What is unique about the pupil in a ruptured globe?

It is often irregular and the irregularity points toward the site of rupture.

31

Why are anti-emetics administered in a patient with a ruptured globe?

Vomitting raises IOP and can cause further extravasation of globe contents.