Orbital fractures and head injury 1

Question 1

Which bones make up the skull

Answer 1

Occipital
Parietal
Temporal
Frontal
Sphenoid
Ethmoid
Nasal
Lacrimal
Maxilla
Zygomatic
Mandible

Question 2

What bones make up the orbit

Answer 2

Frontal bone
Zygomatic
Maxilla
Lacrimal bone
Ethmoid
Sphenoid (lesser and greater
wings of sphenoid)
Palatine bone

Question 3

Which bones make up the orbit rim

Answer 3

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

Question 4

Where are the sinuses located

Answer 4

Maxillary sinus
Ethmoidal sinuses
Frontal sinuses

Question 5

What are the structures within the orbit

Answer 5

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

Question 6

What is the cribriform plate

Answer 6

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

Question 7

Types of head injury

Answer 7

Open head injury
Closed head injury
Coup and countercoup injury

Question 8

What is open head injury

Answer 8

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.

Question 9

What is a closed head injury

Answer 9

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)

Question 10

What is a coup and countercoup head injury

Answer 10

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.

Question 11

Clinical history of head injuries

Answer 11

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.

Question 12

Possible diagnosis’ after head injury

Answer 12

 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)

Question 13

Head injuries and ocular problems

Answer 13

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).

Question 14

What is whiplash

Answer 14

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).

Question 15

What can whiplash cause

Answer 15

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).

Question 16

What is pupil cycle time

Answer 16

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).

Question 17

Optic atrophy secondary to head injury

Answer 17

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).

Question 18

What complicates the orthoptic management of head injuries

Answer 18

Loss of / weakened suppression
 Loss of / weakened fusion
 Incomitance
 Visual field defect
 Insuperable torsion
 VA
 Weakness / paralysis of convergence / divergence
 Exophthalmos
 Enophthalmos

Question 19

What is the conservative orthoptic management

Answer 19

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

Question 20

Eyelid injuries caused by

Answer 20

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.

Question 21

Peri-orbital oedema, swelling and/or haemorrhage

Answer 21

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.

Question 22

Retrobulbar haemorrhage

Answer 22

this is a serious problem that may cause proptosis,
limitation of eye movement and pain. The threat to vision is a medical emergency.

Question 23

Direct damage to the extra-ocular muscles

Answer 23

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.

Question 24

A review of open globe injuries- Agrawal et al (2013)

Answer 24

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)

Question 24

Cause of globe issues

Answer 24

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.

Question 25

Orbital fracture severity

Answer 25

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.

Question 26

Direct trauma is

Answer 26

an injury which results from a direct impact, e.g. a blow to the face

Question 27

Indirect trauma is

Answer 27

an injury which does not result from direct impact, e.g. whiplash

Question 28

Impact to the upper third of the skull more likely results in

Answer 28

a supra-orbital fracture (roof of orbit and superior orbital rim)

Question 29

Impact to the middle third of the skull most likely results in

Answer 29

a fracture of the
zygoma (which can also be displaced), nasal bones, or orbital bones (orbital floor,
medial wall, lateral wall).

Question 30

Le fort fracture 3 classification of facial fractures

Answer 30

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

Question 31

Paediatric orbital fracture commonality

Answer 31

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).

Question 32

Green stick fractures

Answer 32

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)

Question 33

Mean age of orbital fractures in children

Answer 33

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)).

Question 34

Supra- orbital fractures are…

Answer 34

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).

Question 35

Mechanism of supra orbital fractures

Answer 35

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).

Question 36

Characteristics of supra orbital fractures

Answer 36

 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)

Question 37

What is the superior orbital fissure and orbital apex

Answer 37

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.

Question 38

What are symptoms of orbital apex syndrome

Answer 38

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.