DIS - Eye Trauma II: Contusion Injuries - Week 7 Flashcards
Can you see the borders of subconjunctival haemorrhages?
Yes
How long do subconjunctival haemorrhages take to heal?
14 days
Define contusion injury. What causes the damage?
Blunt trauma
Damage is caused by pressure wave across the eye
What happens to IOP with contusion injury?
Transient but large change in IOP
Describe the coup mechanism for damage caused by contusion injury.
Local trauma at the site of impact
Describe the contre-coup mechanism for damage caused by contusion injury.
Injury at the opposite side of the eye caused by shockwaves striking the posterior pole
Describe the ocular compression mechanism for damage caused by contusion injury.
Globe is initially compressed by an object then rebounds, overshoots, and stretches beyond normal shape
List 10 anterior segment manifestations of contusion injury.
Abrasion/laceration Lid/conjunctival ecchymosis Hyphaema Torn iris/iridodialysis Angle recession Lens dislocation Cataract Vossius ring Traumatic uveitis Corneal endothelium damage
List 4 posterior segment manifestations of contusion injury.
Commotio retinae
Haemorrhages
Retinal tear/detachment
Macular oedema/holes
What is the most common form of contusion injury? List 5 symptoms.
Corneal abrasions
- pain
- blepharospasm
- lacrimation
- pseudoptosis
- photophobia
Why is ecchymosis common in the lids?
Vascularity and loose tissue structure
Can ecchymosis spread to the other eye?
Yes, due to subcutaneous supply
What do fractures to the orbit most commonly affect (2)?
The floor and medial wall
Which region of the orbit is the most likely to fracture? Where does it frequently occur along?
The floor of the orbital rim
Frequently occurs along thin bone covering infraorbital canal
Where do the bones of the maxilla tend to collapse into and what happens as a result?
Collpase into the maxillary sinus, orbital contents prolapse into the cavity created
What two muscles are generally affected by fractures of the orbital floor?
Inferior oblique and rectus
-defective elevation
What sinuses are involved with medial wall fractures? What are medial wall fractures most associated with?
Ethmoid sinuses
Medial wall fractures most associated with floor fractures
What are medial wall fractures apparent with?
Air crepitus
-air under skin
What should patients with a medial wall fracture avoid and why?
Avoid blowing nose or air may be forced into the soft tissue of the lids and surrounding skin
Are subconjunctival haemorrhages common or rare?
Quite common
How long do subconjunctival haemorrhages require to resolve and what treatment?
Several weeks
- no treatment needed
- can do cold compress first 24h, then warm compress next day
What is necessary to to confirm subconjunctival haemorrhage? What if you do not see this?
Defineable posterior border
-need imaging if you dont see
What should you do if you suspect idiopathic subconjunctival haemorrhage?
Blood thinners
List four characteristics of ruptures to sphincter pupillae.
Irregular, semi-dilated pupil
Pupils dont react to light/accommodation
Increased glare sensitivity
Monocular diplopia
List four characteristics of iridodialysis.
Often hyphaema
Pupil distortion
Increased glare sensitivity
Monocular diplopia
What should you rule out of the iris with contusion injury?
Hyphaema