Orbital Disorders

Question 1

How does an orbital blow out fracture occur?

Answer 1

Blunt force trauma of an object equal to our greater than the size of the orbit results in the fracture of the orbital floor (maxilla bone). (Upon impact the orbital floor absorbs shockwaves and thus fractures). (Can also be a fracture of the medial wall, however, this is less common)

Question 2

Is an orbital blow-out fracture a common injury?

Answer 2

Yes in fact it is the most common orbital injury.

Question 3

What are the signs and symptoms of an orbital blowout fracture?

Answer 3

Signs and symptoms are variable- they range from asymptomatic with minimal bruising and swelling to diplopia (double vision), enophthalmos, and hypoesthesia of the cheek on the affected side. Herniation (movement) of orbital contents (fat) into maxillary sinus.

Question 4

What is enophthalmos?

Answer 4

Enophthalmos is the posterior displacement of the eyeball within the orbit due to changes in the volume of the orbit (bone) relative to its contents (the eyeball and orbital fat), or loss of function of the orbitalis muscle. BASICALLY AN EYE THATS SUNKEN IN

Question 5

What is hypoesthesia?

Answer 5

Reduced sensation a.k.a numbness

Question 6

Why is hypoesthesia a symptom of an orbital blowout fracture (where the fracture has been of the orbital floor)?

Answer 6

Branches of the trigeminal nerve - specifically the infraorbital nerve passes along the orbital floor- sometimes that nerve is damaged leading to that loss of sensitivity.

Question 7

How can an orbital blow out fracture cause orbital emphysema?

Answer 7

It results from the forceful entry of air into the orbital soft tissue spaces.

Question 8

Whta is brusing around the eye clinically refered to as?

Answer 8

Periorbital haematoma

Question 9

What is Periorbital haematoma?

Answer 9

Bruising around the eye

Question 10

Following an orbital floor fracture why is there a limitation of eye movement (specifically upgaze)?

Answer 10

Because of the entrapment of tissues- i.e. of the eye muscles and the surrounding fat . This causes a mechanical restriction of eye movement. (Nerve trauma could also lead to ascoiated loss of sensation of the cheek on the affected side adding to mechanical restriction).

Question 11

How would you confirm an orbital floor fracture?

Answer 11

Conducting a CT scan Checking VA Check for RAPD Assess ocular motility using hess chart

Question 12

What is RAPD?

Answer 12

Relative Afferent Pupillary Defect (RAPD) is a condition in which pupils respond differently to light stimuli shone in one eye at a time due to unilateral or asymmetrical disease of the retina or optic nerve.

Question 13

What is RAPD?

Answer 13

Relative Afferent Pupillary Defect (RAPD) is a condition in which pupils respond differently to light stimuli shone in one eye at a time due to unilateral or asymmetrical disease of the retina or optic nerve.

Question 14

How would you manage a patient with an orbital floor fracture?

Answer 14

Initially conservative managment (basically means to just monitor carefully). May prescribe Prophylactic antibiotics to reduce risk of infection. May prescibe corticosteroids to reduce swelling. If symptoms don’t improve or if initial symptoms are very severe ( a.k.a large orbital floor fracture) then the patient may need to undergo surgery.

Question 15

What are some indications following an orbital floor fracture that the pateint may need surgery?

Answer 15

-Significant enophthalmos -50% of the floor is damaged -Persisitent Diplopia

Question 16

How does the surgical management of an orbital floor fracture occur?

Answer 16

Essentially the aim is to create an artifical floor thus surgery includes using a variety of synthetic implants e.g polyethylene or metallic mesh to repair the original floor and maintain integrity.

Question 17

What is orbital cellulitis?

Answer 17

Orbital cellulitis is an infection of the soft tissues in the orbit posterior to the orbital septum

Question 18

How does orbital cellulitis occur?

Answer 18

Occurs commonly from bacterial infection spread via the paranasal sinuses

Question 19

If left untreated what can orbital cellulitis lead to?

Answer 19

Sight loss and potentially fatal cerebral complications.

Question 20

Is orbital cellulitis deemed as a medical emergency?

Answer 20

Yes

Question 21

What condition is orbital cellulitis difficult to diffrentiate from?

Answer 21

Pre-septal cellulitis

Question 22

What are clinical features of Orbital Cellulitis?

Answer 22

Periorbital swelling

Severe orbital pain

Fever

Conjunctivitis and chemosis

Loss of colour vision

Proptosis

Impaired movement of the eye +/- RAPD

Question 23

What is chemosis?

Answer 23

Chemosis is swelling of the tissue that lines the eyelids and surface of the eye (conjunctiva). Chemosis is swelling of the eye surface membranes because of accumulation of fluid.

Question 24

What is proptosis?

Answer 24

Proptosis is protrusion of the eyeball (basically eyeball sticks outwards). Exophthalmos means the same thing.

Question 25

What is the treatment for Orbital Cellulitis?

Answer 25

Hospitalisation Imaging High dose of _IV antibiotics_ May need surgical intervention.

Question 26

What is the difference in symptoms between Pre-septal and orbital cellulitis?

Answer 26

Add Images

Question 27

What is the most common thyroid eye disease?

Answer 27

Graves Disease

Question 28

What is Graves's disease?

Answer 28

An autoimmune disease.

Question 29

Is graves disease associated with hyperthyroidism or hypothyroidism?

Answer 29

Hyperthyroidism - so an increase in secretion of thyroid hormone

Question 30

What happens in Grave's disease?

Answer 30

The immune system mistakenly attacks the thyroid which causes it to become overactive.

Question 31

How does Grave's disease affect the eye?

Answer 31

Exophthalmos, autoimmune inflammation of extraocular muscles (which therefore swell) as well as swollen Retrobulbar tissues

Question 32

What is retrobulbar?

Answer 32

Area located behind the globe of the eye (i.e. the eyeball).

Question 33

What are symptoms of Grave's Disease?

Answer 33

Grittiness of the eyes - bc eyelids can't close so areas of the eye are drying out essentially kerititis. Photophobia (increased light sensitivity) Lacrimation (flowing of tears)- because eyelids can't close so uneven spreading of tears across surface (and ofcourse ocular surface is drying out from eyelids not being able to close properly). Pressure or pain in the eyes Loss of VA and colour vision if Optic Nerve stretched enough as eyes are bulging out.

Question 34

What are clinical signs of Grave's Disease?

Answer 34

Periorbital oedema Lid retraction – upper and lower Lid lag Proptosis (exophthalmos) Conjunctival Oedema (chemosis) Optic neuropathy

Question 35

What is lid lag?

Answer 35

Lid lag is the static situation in which the upper eyelid is higher than normal with the globe in downgaze. The eyelid takes longer to fall back to normal position after looking up. (An early sign of Grave's Disease).

Question 36

What is corneal desiccation?

Answer 36

pertains to the area of the cornea not adequately resurfaced with tears (can be seen nicely with fluorescin).

Question 37

What tests would you do to assess thyroid eye disease?

Answer 37

Thyroid function Tests CT scans

Question 38

How would you manage thyroid eye disease?

Answer 38

Conservatively ( i.e. carefully monitor - this is done initially) Immunosupressive drugs/surgery Decompression Surgery - bones limit expansion of orbital tissue thus eyeball pushes forward and so when all other forms of management fail, an operation may be done to take out walls of the orbit in order to allow the tissue to take up this space rather than push the eyball forward (as pushing eybal forward stretches/damages the optic nerve). (This surgery is a last resort)!