2: Ocular trauma Flashcards
Where do the majority of eye injuries occur?
At work
What are some mechanisms of eye injury?
Blunt force trauma
Penetrating injuries
Burns
What must be recorded before examining the eyes of someone with an injury?
Visual acuity
How is the eye examined?
Front to back
lids, conjunctiva, cornea, anterior segment, pupils, fundus
What dye is used to examine the eyes?
What colour does it turn under blue light?
Fluorscein
green
- History is key
- Visual acuity
- Fluorescein
What type of fracture can be caused by orbital trauma?
Orbital blowout fracture
What sign is produced on a CT head by an orbital blowout fracture?
Tear drop sign
prolapse of fat into maxillary sinus
Which walls of the orbit are most commonly damaged by orbital blowout fractures?
Which muscle is commonly trapped?
Medial and inferior walls
Inferior rectus
What sign is caused by inferior rectus entrapment in an orbital blowout fracture?
What symptom does this cause?
Inability to ELEVATE affected eye because muscle is trapped (contracted)
Diplopia
What type of bleeding is caused by blunt force trauma?
Subconjunctival haemorrhage
What should you be suspicious of in all traumatic eye injuries involving significant force?
Globe rupture
What is traumatic uveitis?
Inflammation caused by proteins released by traumatic injury
think also: sympathetic ophthalmia
What is blood in the anterior chamber called?
What does it indicate?
What is pus in the anterior chamber called?
Hyphaema
Significant intraocular injury
Hypopyon
What’s this?
Dislocated lens
What’s this?
Retinal detachment
What’s this?
Choroid tear
What is commotio retinae?
Bruised retina
What name is given to a bruised retina?
Commotio retinae
What is a laceration?
Deep cut/tear in surface
Corneal lacerations cause a communication between the outside world and the eye.
What can this cause?
What sign is produced on fluorescein staining?
Infection
Seidel test (aqueous fluid passes through communication and dilutes the fluroscein)
In what situation may the pupil become teardrop shaped?
Corneal laceration
Iris acts like omentum in Crohn’s, plugging the injury
What is the Seidel test?
Dilution of fluorescein
Caused by corneal laceration, aqueous fluid passing through communication
What autoimmune disease causes bilateral granulomatous uveitis in response to trauma in one eye?
What may it result in if untreated?
Sympathetic ophthalmia
Total blindness
What part of the anterior eye must be examined for foreign bodies?
Underneath upper lids
eye-e sub-tarsal
What will occur if residual metal is left in the cornea?
Rust ring
What medication is usually used for corneal abrasions / foreign bodies?
What are the two benefits of this?
Chloramphenicol drops QDS for a week
Antibacterial and moisturising
What investigation should be done to find intraocular foreign bodies?
X-ray orbits
(Acids / alkalis) cause more damage to the eye.
Why?
Alkalis
Rapidly penetrate, severely burn and cause scarring
Acid burns are self-limiting
Where are stem cells found in the eye?
Limbus
Alkali burns cause limbal ___.
Why is this so serious?
limbal ischaemia
only source of stem cells
Is the cornea usually vascularised?
No
so corneal vascularisation is a sign of serious injury
What two common chemicals are very alkaline and can cause chemical burns?
Lime
Cement
How are chemical burns treated?
Toxbase
pH paper
Slit lamp assessment
How do you treat lime / cement burns?
Physically remove
DON’T IRRIGATE because they create alkaline solutions which will make things worse
How are chemical burns treated?
Irrigate with at least 2L of saline
Keep checking pH throughout
A high percentage of eye injuries are ___.
preventable
How are eye injuries prevented?
Safe practice - goggles, training, guidelines
Education
