Orbital fractures and head injury 1 Flashcards
Which bones make up the skull
Occipital
Parietal
Temporal
Frontal
Sphenoid
Ethmoid
Nasal
Lacrimal
Maxilla
Zygomatic
Mandible
What bones make up the orbit
Frontal bone
Zygomatic
Maxilla
Lacrimal bone
Ethmoid
Sphenoid (lesser and greater
wings of sphenoid)
Palatine bone
Which bones make up the orbit rim
Superior orbital rim & upper medial rim - frontal bone
Lateral orbital rim - zygomatic bone
Inferior and lower medial rims - maxilla
Orbital floor - upper border of the maxillary sinus
Medial rim separating orbit from nose - lacrimal bone
Medial wall and part of the posterior wall - ethmoid
Rest of posterior orbit - 2 wings of the sphenoid bone, the continuation of the
lacrimal bone from the medial wall and orbital process of the palatine bone
Where are the sinuses located
Maxillary sinus
Ethmoidal sinuses
Frontal sinuses
What are the structures within the orbit
Optic foramen
* Superior orbital
fissure
* Inferior orbital
fissure
* Infraorbital
foramen
* Infraorbital notch
* Trochlear notch
* Supraorbital
notch
* Optic nerve
* Ophthalmic
artery
* MR muscle
* LR muscle
* IR muscle
* SR muscle
* IO muscle
* SO muscle
* LPS muscle
* Lacrimal nerve
* Frontal nerve
* Oculomotor
nerve
* Trochlear nerve
* Nasociliary
nerve
* Abducens nerve
* Tendinous ring
What is the cribriform plate
Part of the ethmoid bone
Midline bone – part of the orbit, cranium & the nose
Transmits the olfactory nerves which allow a sense of smell
A fracture to the cribriform plate can lead to cerebro-spinal fluid (CSF) leaking
into the nasal cavity and a loss of sense of smell
Types of head injury
Open head injury
Closed head injury
Coup and countercoup injury
What is open head injury
This may also be called a ‘penetrating head injury’ as it is caused by an object
breaking the skull and entering the brain. This injury is often focal - affecting a
specific area of the brain. There may be an obvious compound fracture of the skull or
a more subtle fracture of the cribriform plate, paranasal air sinuses and / or the
middle ear. Whilst other fractures may be initially less obvious, they are not less
serious.
What is a closed head injury
Caused by a blow to the skull, but where the skull remains closed or intact. Damage
to the brain can be large areas of bruising, tearing and bleeding or can be more
localised to areas of bony prominences within the skull (i.e. the sphenoid ridges)
What is a coup and countercoup head injury
Coup and contrecoup injuries are associated with closed head trauma. The coup
injury occurs at the area of impact (direct blow) and the contrecoup injury occurs
on the opposite side of the impacted area (counter-blow). They may occur
individually or together. Coup and contrecoup injuries are associated with cerebral
contusion (bruising of the brain) and both are focal brain injuries, rather than diffuse
injuries, which occur over a more widespread area.
Clinical history of head injuries
Most patients present with a history of a head injury (examples: RTA (road traffic
accident), accident at work, sports injury or assault) BUT patients may not present
immediately after trauma.
Blunt head injury patients are more likely to be male, in a US study the ratio was M
1.5 : F 1 (Unger et al, 1990). In a study by Poon et al (1999) 55% of those with a
facial injury had an orbital injury and 16% of patients involved in a serious trauma
had orbital/ocular injuries.
Possible diagnosis’ after head injury
Neurogenic palsy
Damage to the extra ocular muscle – myogenic
Orbital fracture
Accommodation insufficiency / paralysis
Convergence insufficiency / paralysis
Loss of / weakened suppression
Loss of / weakened fusion
Visual field defect – especially if visual cortex or visual pathways involved
Damage to the optic nerve
Damage to the peri-ocular structures
Damage to the globe
Supra nuclear palsy and a skew deviation (lectures on these later)
Head injuries and ocular problems
A head injury may be sufficient to cause concussion. There may also be an
abnormality in local blood flow, haemorrhage, cell destruction or damage to the white
matter. Cranial nerve palsies are more common than a weakness or pareses of an
individual extraocular muscle. Fusion may be weakened or completely lost following
a head injury (called central fusion disruption). Convergence and/or accommodation
may be affected, causing a range of problems from paralysis to insufficiency.
Convergence & divergence paralysis has been reported to co-exist after head injury
(Nashold & Seaber, 1972).
What is whiplash
A closed head injury where the lower part of the body is thrust forward and the neck
is thrown into hyperextension (head moves backwards), then the neck is thrown into
flexion (head moves towards the chest).
What can whiplash cause
A range of ocular problems have been described following whiplash including blurred
vision (most common), diplopia, seeing spots in front of the eyes, objects receding,
CI (Burke and Orton, 1993) and reduced accommodation and ‘pupil cycle time’
(Brown, 1991).
What is pupil cycle time
Pupil cycle time involves using a slit lamp light to induce pupil constriction and timing
how many regular oscillations of pupil construction and relaxation occur using a stop
watch. Evidence from pharmacological testing suggests that pupil cycle time is a
sensitive measure of dysfunction of the parasympathetic efferent limb of the pupillary
light reflex. It has been suggested that whiplash associated with defective
accommodation may be caused by interruption of the sympathetic innervation to the
eye (Brown, 2003).
Optic atrophy secondary to head injury
Direct optic neuropathy is caused by direct damage to the optic nerve (e.g. in a
penetrating head injury). Indirect optic neuropathy is an injury to the optic nerve due
to the non-penetrating effects of trauma (e.g. haemorrhage, oedema). Both direct
and indirect optic neuropathy may result in optic atrophy. In optic atrophy the patient
will have a severe reduction in VA, a pale optic disc and an RAPD. This may be
unilateral or bilateral. Subtle optic atrophy should be considered if no other cause is
found in a case of loss of previously good VA. There are limited treatment options;
usually observation for spontaneous improvement is recommended (Steinsapir &
Goldberg, 2011).
What complicates the orthoptic management of head injuries
Loss of / weakened suppression
Loss of / weakened fusion
Incomitance
Visual field defect
Insuperable torsion
VA
Weakness / paralysis of convergence / divergence
Exophthalmos
Enophthalmos
What is the conservative orthoptic management
Fresnel prisms
Advice on using an abnormal head posture or head movements
Orthoptic exercises
Monocular occlusion – total or sector
Bangerter foils, occlusive tape (blender / leukosilk)
Refractive correction – consider near ADD
Eyelid injuries caused by
lacerations to the eyelids may involve the lid margins and result in
tissue loss, as well the canaliculi and lacrimal glands may be involved (may need to
protect the cornea with artificial tears or taping of lids). Ptosis may be caused by
swelling of the upper lid or damage to the LPS. Surgical repair may be needed.
Peri-orbital oedema, swelling and/or haemorrhage
If the oedema is significant – you will need to carefully examine whether
the patient can open their eye to test their VA. Need to ensure globe is intact and
functioning.
Retrobulbar haemorrhage
this is a serious problem that may cause proptosis,
limitation of eye movement and pain. The threat to vision is a medical emergency.
Direct damage to the extra-ocular muscles
this may be a muscle laceration or an
avulsion. Need to carefully look for globe damage and how far back damage
extends. If recent onset damage – there may be swelling, whereas if damage
acquired some time ago – there may be scar tissue.
A review of open globe injuries- Agrawal et al (2013)
Corneal abrasion - mild
Subconjunctival haemorrhage
Hyphaema (blood in anterior chamber)
Penetrating injury (ophthalmic emergency ?foreign body)
Lens damage and/or dislocation
Retinal detachment, haemorrhage, contusion
Choroidal ruptures
Optic nerve damage (direct or indirect optic neuropathy)
Cause of globe issues
May result from blunt or sharp trauma and can cause devastating damage. A globe
injury is usually an ophthalmic emergency and may require urgent surgical repair.
Orbital fracture severity
Orbital fractures can vary hugely in severity, from a minimally displaced fracture of an isolated part of the orbit requiring no surgery, to complex fractures of multiple orbital bones that require surgery and reconstruction by maxillofacial surgeons.
Direct trauma is
an injury which results from a direct impact, e.g. a blow to the face
Indirect trauma is
an injury which does not result from direct impact, e.g. whiplash
Impact to the upper third of the skull more likely results in
a supra-orbital fracture (roof of orbit and superior orbital rim)
Impact to the middle third of the skull most likely results in
a fracture of the
zygoma (which can also be displaced), nasal bones, or orbital bones (orbital floor,
medial wall, lateral wall).
Le fort fracture 3 classification of facial fractures
Le Fort I fracture
▪ No ophthalmic significance, involves the nasal septum and travels laterally
▪ Also known as Guerin fracture or ‘floating palate’
Le Fort II fracture
▪ Occurs following a blow to the mid or lower maxilla
▪ Pyramid shaped fracture, relevant ophthalmically
▪ Associated with serious intracranial injury and increased mortality (Bellamy et
al, 2013)
▪ Involves orbital rim and the floor of the orbit
▪ Extends from the nasal bridge, through frontal processes of the maxilla,
inferolaterally across lacrimal bone, along floor of orbit to zygomatic
suture, then along infraorbital foramen, across the maxilla and ending
in the pterygo-maxillary fissure
Le Fort III fracture
▪ This is the most ophthalmically relevant of the Le Fort fractures, as it
extensively involves the orbit
▪ Associated with serious intracranial injury (Bellamy et al, 2013)
▪ Occurs following an impact to the nasal bridge or upper maxilla
▪ Starts at nasofrontal & frontomaxillary sutures, extends along medial
orbital wall, through the nasolacrimal groove & ethmoid bones. The
thicker sphenoid bone posteriorly usually prevents continuation of the
fracture into the optic canal. The fracture continues along orbital floor
along the inferior orbital fissure, superolaterally through lateral orbital
wall, through zygomaticofrontal junction and zygomatic arch. A branch
of fracture extends through ethmoid, through the vomer, and through
interface of the pterygoid plates to the base of the sphenoid
▪ This type of fracture predisposes the patient to CSF rhinorrhea more
commonly than the other types
Paediatric orbital fracture commonality
Children are less likely to sustain an orbital fracture as they have a relatively small
face compared to prominent cranium and have more cheek fat. They are therefore
more likely to sustain a fracture to the upper face & skull. Superior orbital fractures
have been found to be more likely in children (Patel & Bauer, 1998).
Green stick fractures
Due to the physiology of their bones greenstick fractures are more likely. In orbital
fractures, an adult fracture is more likely to be comminuted (shatter), whereas a
paediatric fracture would be more likely to be a clean ‘linear’ fracture. Paediatric
patients are also more prone to ‘trap door fractures’, with increasing risk of them in
younger patients (Gerber et al, 2013)
Mean age of orbital fractures in children
12.5 years and 92% were male (Hatton et
al, 2001).
The most common aetiology for a childhood orbital fracture is a sports
injury (Egbert et al, 2000). There are numerous review articles of paediatric orbital
fractures (Wei & Durairaj (2011), Gerber et al (2013)).
Supra- orbital fractures are…
A fracture of the roof of the orbit and/or superior orbital rim. Uncommon in both
adults and children, although children are at increased risk of supraorbital fractures
due to relative prominence of the cranium and a lack of frontal sinus pneumatisation
(Patel & Brauer, 1998).
Mechanism of supra orbital fractures
can occur due to a direct blow to the frontal region or an indirect blow to
the base of the skull which radiates to the roof of the orbit (contre-coup effect).
Characteristics of supra orbital fractures
Superior orbital swelling and haemorrhage
Oedema of upper lid – may have ptosis ?traumatic ptosis
Supra-orbital anaesthesia/hypo-anaesthesia
Superior rectus or superior oblique damage / palsy
Dislocation /damage to trochlear
Depression of supra-orbital rim – exophthalmos and displacement of the
globe
Retrobulbar haemorrhage – generalised limitation of movement
Emphysema
Leakage of CSF – may indicate a fracture of the cribriform plate
Infection (which can lead to meningitis)
What is the superior orbital fissure and orbital apex
The superior orbital fissure is a cleft, lying between greater & lesser wings of the
sphenoid bone. It contains 4th, 6th & superior & inferior divisions of the 3rd cranial
nerves; also the lacrimal, frontal and nasociliary branches of the ophthalmic division
of the trigeminal nerve (V1).
The orbital apex is the posterior narrow part of the orbit.
What are symptoms of orbital apex syndrome
Can occur when a fracture involves the apex of the orbit. There may be involvement
of the 2nd, 3rd, 4th, 5th & 6th cranial nerves & the central retinal artery & veins. There
may be proptosis and direct damage to the optic nerve, causing a reduction in VA
and optic atrophy.
