Orbital Disorders Flashcards
How does an orbital blow out fracture occur?
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)
Is an orbital blow-out fracture a common injury?
Yes in fact it is the most common orbital injury.
What are the signs and symptoms of an orbital blowout fracture?
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.
What is enophthalmos?
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
What is hypoesthesia?
Reduced sensation a.k.a numbness
Why is hypoesthesia a symptom of an orbital blowout fracture (where the fracture has been of the orbital floor)?
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.
How can an orbital blow out fracture cause orbital emphysema?
It results from the forceful entry of air into the orbital soft tissue spaces.
Whta is brusing around the eye clinically refered to as?
Periorbital haematoma
What is Periorbital haematoma?
Bruising around the eye
Following an orbital floor fracture why is there a limitation of eye movement (specifically upgaze)?
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).
How would you confirm an orbital floor fracture?
Conducting a CT scan Checking VA Check for RAPD Assess ocular motility using hess chart
What is RAPD?
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.
What is RAPD?
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.
How would you manage a patient with an orbital floor fracture?
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.
What are some indications following an orbital floor fracture that the pateint may need surgery?
-Significant enophthalmos -50% of the floor is damaged -Persisitent Diplopia
How does the surgical management of an orbital floor fracture occur?
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.
What is orbital cellulitis?
Orbital cellulitis is an infection of the soft tissues in the orbit posterior to the orbital septum
How does orbital cellulitis occur?
Occurs commonly from bacterial infection spread via the paranasal sinuses
If left untreated what can orbital cellulitis lead to?
Sight loss and potentially fatal cerebral complications.
Is orbital cellulitis deemed as a medical emergency?
Yes
What condition is orbital cellulitis difficult to diffrentiate from?
Pre-septal cellulitis
What are clinical features of Orbital Cellulitis?
Periorbital swelling
Severe orbital pain
Fever
Conjunctivitis and chemosis
Loss of colour vision
Proptosis
Impaired movement of the eye +/- RAPD
What is chemosis?
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.
What is proptosis?
Proptosis is protrusion of the eyeball (basically eyeball sticks outwards). Exophthalmos means the same thing.
What is the treatment for Orbital Cellulitis?
Hospitalisation
Imaging
High dose of IV antibiotics
May need surgical intervention.
What is the difference in symptoms between Pre-septal and orbital cellulitis?
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What is the most common thyroid eye disease?
Graves Disease
What is Graves’s disease?
An autoimmune disease.
Is graves disease associated with hyperthyroidism or hypothyroidism?
Hyperthyroidism - so an increase in secretion of thyroid hormone
What happens in Grave’s disease?
The immune system mistakenly attacks the thyroid which causes it to become overactive.
How does Grave’s disease affect the eye?
Exophthalmos, autoimmune inflammation of extraocular muscles (which therefore swell) as well as swollen Retrobulbar tissues
What is retrobulbar?
Area located behind the globe of the eye (i.e. the eyeball).
What are symptoms of Grave’s Disease?
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.
What are clinical signs of Grave’s Disease?
Periorbital oedema
Lid retraction – upper and lower
Lid lag
Proptosis (exophthalmos)
Conjunctival Oedema (chemosis)
Optic neuropathy
What is lid lag?
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).
What is corneal desiccation?
pertains to the area of the cornea not adequately resurfaced with tears (can be seen nicely with fluorescin).
What tests would you do to assess thyroid eye disease?
Thyroid function Tests CT scans
How would you manage thyroid eye disease?
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)!
