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
If there is iris damage with contusion injury, is it advisable to do gonioscopy?
Not for the first week
List 5 tests to do to assess the iris with contusion injury.
DFE
VA
IOP
Pupils
CV
What may be used in traumatic iritis initially if due to corneal abrasion and over what other drug?
Cycloplegic initially rather than steroids
Describe how contusion injury can result in angle recession (3).
Cornea is abruptly forced back, pressing on the iris, and against the lens
Aqueous cannot move into the posterior chamber, and moves into ciliary body
This tears the anterior face of the ciliary body at insertion
What can occur with angle recession and how long later?
Unilateral glaucoma months or years later
What do you expect of the pupil with angle recession due to contusion injury?
Traumatic mydriasis
Define hyphaema. What causes it?
Blood in the anterior chambel
Due to the rupture of iris or ciliary body vessels
What happens with hyphaema in most cases?
Resorbed without serious consequences
If not resorbed in a few days, what can occur with hyphaema (3)?
Increased IOP
Blood staining the cornea
Secondary glaucoma
How should cases of hyphaema be managed by optometrists?
Refer all cases unless its only trace
Describe the five grades of hyphaema.
Trace - RBCs visible, no layering
Grade 1 - <1/3rd AC depth
Grade 2 - 1/3 to 1/2 AC depth
Grade 3 - 1/2 to 90% AC depth
Grade 4 - 100% AC depth
What is the management with hyphamea (5)?
No physical activity
Bed rest with 30 degree head elevation
5% homatropine qid
Monitor for reebleed
Acetaminophen for pain
What two medications hsould individuals with hyphaema not take?
Aspirin
NSAIDs
How should cases of hyphaema be reviewed?
Every day for 3-4 days
What should you do if you see inflammation and IOP increase with hyphaema?
Inflammation - pred acetate 1% q2h
IOP increase - timolol 0.5% bid
When should you do gonioscopy on patients with hyphaema?
Several weeks after it is cleared
List 6 features of partial or total lens dislocation.
Reduced VA
Irregular astigmatism
Myopic shift
Abnormal ret reflex
Monocular diplopia
Deeper AC
List a feature of partial lens dislocation.
Tearing of suspensory ligaments
What is a vossius ring and in what age group is it more common?
Circle of iris pigment on the lens from impact of iris against lens
More often in the young
List three features of a rosette cataract. What two injuries can cause it? Is its onset acute or delayed?
Vacuoles, oedema, and fibre degeneration
Onset may be delayed
Contusion or perforation injuries
Are diffuse cataracts common or rare?
Rare
What are diffuse cataracts usually associated with? What may occur as a result (2) and with what?
Torn capsule
-secondary glaucoma or anterior uveitis can occur if the tear is large
Are zonular cataracts common or rare?
Rare
How do zonular cataracts appear?
Series of concentric opacities surrounded by clear lens
List 9 posterior segment damages you may see as a result of contusion injury.
Oedema
Cysts
Holes
Necrosis
Atrophic retinal changes
Commotio retinae
Retinal detachment
Haemorrhages
Choroidal tears
What is commotio retinae?
Retinal oedema
What appearance may the retina have with contusion injury? Is it transient or irreversible? What areas are usually affected and what layers of the retina is it confined to? Does it affect vision? Can it cause permanent damage?
Retina may appear milky within a few hours
Transient and reversible (usually four days)
Affects area surrounding ONH and macula
Confined to outer retinal areas
Vision reduced
May have permanent impairment due to development of pigmentary changes at the macula, cyst, or hole
What may occur with severe commotio retinae?
Cystoid muller cells may rupture, exacerbating oedema
When do choroidal tears often occur? What consequence does it have?
Occurs when trauma is combined with increase in IOP
Allows fluid to enter suprachoroidal space
Where do choroidal tears usually occur (2)?
Between the disc and macula or temporal to the macula
Wha can choroidal tears lead to?
Haemorrhage
Where do retinal detachments tend to occur if shortly after trauma? Otherwise, where?
Typically supero-temporal periphery
Otherwise commonly supero-nasal
What is a strong indicator of retinal detachment?
Tobacco dust in the anterior vitreous
What are three diseases that increase the risk of trauma related retinal detachment?
High myopia
Peripheral retinal degeneration
Aphakia
Are myopic changes more or less common with trauma? Explain why and note if it is permanent or transient.
More common due to spasm of accommodation
Usually transient
What five things should you assessif you suspect contusion injury?
Orbital fracture
EOM entrapment
Globe position
Globe rupture (seidel test)
Anterior and posterior segments
What are 7 screening tests to do if you suspect contusion injury?
VA
Pupils
Oculomotility
Colour vision
NPA
Amsler
IOP
Should you refer if there is retinal/ON dmaage with contusion injury?
Yes
What test is done to assess bone damage?
CT scan
