Orbital Disorders Flashcards
What is an orbital blow out fracture?
Trauma caused by a blunt object striking the eye
What bones does a blow out fracture affect?
It damages the floor of the orbit which is called the maxilla and sometimes can also damage the medial wall which is the ethmoid bone
Describe the ethmoid bone
A paper thin bone
What lies underneath the orbital bones
Under the bones is an air filled space called the sinus eg. ethmoid sinus
What happens when the floor of the orbit it broken?
There is just space underneath so all the surrounding orbital fat and muscle goes into that space
What are some obvious signs of an orbital blow out fracture?
Enophthalmos, subconjunctival haemorrhage, periorbital haematoma (bruising/swelling)
What are some not so obvious signs?
Diplopia, orbital emphysema, hypoesthesia of the cheek on the affected side
What is orbital emphysema?
Forceful entry of air into the space
Which nerve can be damaged from a fracture and what does this nerve supply?
Infra orbital part of the trigeminal nerve.
It supplies sensation to the skin of cheek
Why may the patient experience diplopia after an orbital blow out fracture
If the floor is damaged, the eye is mechanically restricted so they will have a problem looking up so diplopia is experience in primary position but greater on upgaze
What test must you perform on a suspect orbital blow out fracture?
Ocular motility
RAPD
VA
What further tests are needed?
CT scan gives good resolution shows soft tissues and bones
How would you manage an orbital blow out fracture?
Depends on severity
Monitor or send to A&E if severe
Prophylactic antibiotics to reduce risk of infect
Corticosteroids and cold compress to reduce swelling
Does the orbital blow out fracture require surgery?
If diplopia persists, significant enophthalmos, 50% of orbital floor involved
How is surgery done?
Synthetic implants eg. polyethylene or metallic mesh is used to repair the broken orbital floor
What is orbital cellulitis?
Bacterial infection of soft tissues of the eye behind the orbital septum
What is the orbital septum?
It holds back the orbital contents
Who does orbital cellulitis commonly occur in?
People with sinus infections
The infection spreads via paranasal sinus to the orbital septum
What are the signs of orbital cellulitis?
Proptosis, Motility pain and discomfort,
VA, colour vision reduced in severe cases, RAPD present in severe cases
Fever, swelling of orbit and between brows, conjunctivitis
How would you manage orbital cellulitis?
Refer emergency as sight and life threatening.
Why is orbital cellulitis life threatening?
The infection can spread from the orbit to the cranial cavity
What will they do at the hospital for orbital cellulitis?
They are put on intravenous antibiotics to fight the infection
CT scan is done to investigate
May require surgery to drain the sinus of infection
What is preseptal cellulitis?
Infection infornt of the orbital septum, less serious
What are the signs of preseptal cellulitis?
Looks the same as orbital cellulitis meaning you will see swelling but no proptosis or RAPD, motility, VA, colour vision all normal
How would you manage preseptal cellulitis?
Refer emergency, don’t try to differentiate, even in hospitals the will be put on antibiotics straight away
What is thyroid eye disease?
Commonly caused by Grave’s disease
Autoimmune disease
Elevated thyroid levels
What are the signs of TED?
Inflammation of EOMs and retrobulbar tissues
Exophthalmos, lid retration, lid lag
Swollen neck
Conjunctival oedema, corneal desiccation
What are the symptoms of TED?
Grittiness, photophobia, lacrimation, loss of VA and colour vision if optic nerve is involved
How can TED cause dry eyes and keratitis?
TED patient is not able to close their eyes fully because the eyeball is sticking out. This causes the eye surface to dry out
How can optic nerve be affected in TED?
As they eye is being pushed forward the optic nerve is being stretched
What can occur in extreme cases of TED?
Optic neuropathy
How would you manage TED?
Monitor
Immunosuppression
Decompression surgery
What is Immunosuppression?
Suppressing the body’s ability to fight disease, this is deliberately induced by drugs
What is Decompression surgery?
Taking out the orbit walls to create space for the eye to go back in
Only done when vision is threatened of for cosmetic purposes
Is TED reversible when thryoid levels come back down?
Sometime TED will continue to develop even if thyroid levels return back to normal
