Head injuries and orbital fractures

Question 1

what are the bones that make up the skull

Answer 1

Occipital
* Parietal
* Temporal
* Frontal
* Sphenoid
* Ethmoid

Nasal
* Lacrimal
* Maxilla
* Zygomatic * Mandible
(only p tell friends something extra n late moo m z )

Question 2

what are the bones that make up the orbit

Answer 2

frontal

ethmoid

paletine

sphenoid - lesser and frontal

zygomatic

maxilla

lacrimal

Question 3

what are the bones of the orbital rim

Answer 3

superior orbital rim and upper medial rim on the frontal bone

lateral orbital rim on the zygomatic bone

inferior and lower medial rims on the maxilla

orbital floor on the upper border of the maxillary sinus

medial rim separating the orbit from the nose - lacrimal bone

medial wall and part of the posterior wall - ethmoid

rest of the posterior orbit - 2 wings of the sphenoid bone , the continuation of the lacrimal bone from the medial wall and the orbital process of the palatine bone

Question 4

where are the sinuses located

Answer 4

maxillary sinuses on the cheeks

frontal sinuses above eyebrows

ethmoidal sinus

on the outer bridges of nose / inner part of eye

Question 5

what are the main 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

medial rectus muscle
lateral rectus muscle

inferior rectus muscle

superior rectus muscle

inferior and superior oblique muscles

levator palpabele superiors

lacrimal nerve

frontal nerve

ocular motor nerve

trochlear nerve

nasocillary nerve

abducens nerve

tedious ring

Question 6

what is the cribifrom plate

Answer 6

part of the ethmoid bone

midline bones - part of the orbit , cranium and nose

transmits the olfactory nerves which allows for a sense of smell

a fracture to the cribriform plate can lead to css leaking into the nasal cavity and a loss of sense of smell

Question 7

what are the three types of head injury

Answer 7

open head injury , closed head injury, coup and contrecoup injuries

Question 8

what is a 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 are coup and countercoup injuries

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

what diagnoses are important to consider after a head injury

Answer 11

neurogenic palsy

damage to the eom- 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

Question 12

what ocular problems can head injuries cause

Answer 12

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 13

what ocular problems can be caused by whiplash

Answer 13

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).
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 14

how is optic atrophy related to a head injury

Answer 14

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 15

how are patients with head injuries orthoptically managed

Answer 15

In all cases of head injury (recent onset or longstanding) your orthoptic management may be complicated by…
 Loss of / weakened suppression  Loss of / weakened fusion
 Incomitance
 Visual field defect
 Insuperable torsion
 VA
 Weakness / paralysis of convergence / divergence
 Exophthalmos
- enopthalmos

Question 16

how are patients conservatively managed

Answer 16

• 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 17

what type of orbital injuries can be caused

Answer 17

eyelid injuries - lacerations to the eyelids that may involve the lid margins , result in tissue loss

canaliculi and lacrimal glands may be involved - may need to protect the cornea with artificial tears or taping of the lids

ptosis may be caused by swelling of the upper lid or damage to the lps

peri- orbital oedema - welling and/or haemorrhage (see soft tissue injury V orbital fracture). 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.

Question 18

what are the type of globe injuries

Answer 18

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

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 19

what are the type of globe injuries

Answer 19

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

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 20

what are the types of orbital fractures

Answer 20

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

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

Any part of the orbit can fracture. In the case of direct trauma, the location of the orbital fracture will depend on which area of the face sustains the impact and the mechanism of the injury. Impact to the upper third of the skull will be more likely to result in a supra-orbital fracture (roof of orbit and superior orbital rim), whereas an impact to the middle third of the skull will be more likely to result in a fracture of the zygoma (which can also be displaced), nasal bones, or orbital bones (orbital floor, medial wall, lateral wall

Question 21

what are le fort facial fractures

Answer 21

Classification of facial fractures into 3 types (Le Fort I, II and III) which are essentially commonly occurring lines of facial fracture.

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 22

how likely are children to develop paediatric orbital fractures

Answer 22

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

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).
Dr Gemma Arblaster – Year 2 2022

Dr Gemma Arblaster – Year 2 2022
Mean age of orbital fracture in childhood = 12.5 years and 92% were male (Hatton et al, 2001). The most common aetiology for a childhood orbital fracture is a sports injury

Question 23

what is a supra orbital fracture

Answer 23

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: 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:
 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

Question 24

where are the superior orbital fissure and orbital apex located

Answer 24

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 25

what is superior orbital fissure syndrome

Answer 25

Can occur when a fracture involves the superior orbital fissure. There may be involvement of the 3rd, 4th, 5th (ophthalmic branches) & 6th cranial nerves.

Question 26

what is orbital apex syndrome

Answer 26

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.

Question 27

what are lateral wall fractures

Answer 27

A fracture of the zygoma can occur, but more commonly it is displaced upwards or downwards from its attachment, which is determined by the direction of the blow. It may be associated with an orbital floor blow out fracture as well.
Characteristics:
 Oedema and haemorrhage
 Downward displacement can cause enophthalmos, pseudoptosis and a
flattened cheek bone
 Upward displacement can cause exophthalmos and an accentuated cheek bone
 May also have damage to EOM or nerves causing diplopia
 May also have disturbed motility of lower jaw if affecting temporomandibular
joint

Question 28

what is a nano orbital fracture

Answer 28

A fracture to the nasal bones may be isolated or associated with an orbital fracture. Often caused by direct trauma to the mid third of the face.
Characteristics:
 Flattened nose
 Traumatic telecanthus (12-20%) ~ increased distance between medial canthi  Oedema - swollen medial canthal area
 Epitaxis (nose bleed)
 Nasal obstruction
 Damage to lacrimal apparatus

 Emphysema
 Damage to inferior oblique origin (or other EOM or nerve)  Lack of skeletal support on palpation of nose
 CSF leak – consider a fracture of the cribriform plate

Question 29

what is a orbital fracture

Answer 29

fracture due to increased orbital pressure - causes thinnest parts to blow out

weakest part of orbit= maxilla- causing a blow out fracture of orbital floor

next weakest = ethmoid - causing a blowout fracture of the medial wall

Question 30

what is a pure blow out fracture - and a impure blowout fracture

Answer 30

pure - fracture of the internal orbital walls only - e.g. orbital floor

impure- a fracture of the internal orbital walls plus a fracture of the orbital rim

Question 31

what are the two proposed theories for the mechanisms of blow out fractures

Answer 31

Hydraulic theory / blow out theory – the force of the object displaces the globe backwards, increasing the intraorbital pressure with a resulting fracture in the area of least resistance i.e. posterior orbital floor (Smith and Regan, 1959).

Buckling theory – the force of the blow is transmitted through the bone from the orbital rim to the floor of the orbit.

Question 32

what are the different types of pure blow out fractures

Answer 32

Linear or trap door: fracture is open and closed after injury with no loss of orbital contents, yet there may be incarceration of soft tissue/muscle in trap door
Hanging drop of hinged bony fragment: herniation of orbital contents into fracture
Depressed: a piece of the fractured orbit is punched out
Comminuted: fracture of the orbit which shatters into several bony fragments. In an orbital floor blow out fracture of this type the bony fragments are displaced into the maxillary antrum

Question 33

what are the characteristics of orbital blow out fractures

Answer 33

Ecchymosis - ‘black eye’
 Subconjunctival haemorrhage
 Oedema – swelling
 Enophthalmos and pseudoptosis - due to increased orbital space
 Anaesthesia / hypoanaesthesia - ipsilateral cheek and upper lip and teeth in
an orbital floor blow-out fracture (if infraorbital nerve affected )
 Limitation of ocular movement and diplopia – this is a mechanical defect, so
the limitation will be in the position away from the defect
 Orbital floor blow-out fracture – limited elevation (?also depression)  Medial wall blow-out fracture – limited ABDuction (?also ADDuction)
 Pain on attempted movement
 Globe retraction on attempted movement
 Increased IOP on attempted movement
 Orbital emphysema - warned not to blow nose!

Question 34

what is muscle and soft tissue entrapment

Answer 34

An extraocular muscle and/or surrounding soft tissue may become trapped in an orbital fracture site. A trap door orbital floor blow-out fracture is the most common fracture for this to occur. The inferior rectus and/or surrounding soft tissue become trapped – this causes restricted elevation and there may also be globe retraction on attempted elevation. A medial rectus may become trapped in a medial wall fracture has also been reported

Question 35

in what populations are trap door fractures most common

Answer 35

A trap door fracture is more common in children. In a study of 24 children with orbital fractures, 11 were found to have trap door fractures. At the time of surgery 2/3 of those with trap door fracture had soft tissue trapped in the fracture site, whereas only 5 had extraocular muscle trapped (Gerber et al, 2013). In a study of 34 children under 18 who presented for surgery with an isolated orbital floor fracture, 69% had the inferior rectus trapped in the fracture site (Egbert et al, 2000). In children presenting with signs of an orbital fracture, those with nausea and vomiting are more likely to have an entrapped muscle and a poorer outcome (Cohen & Garrett, 2003).

Question 36

is surgery reccomended in trap door fractures

Answer 36

f entrapment is suspected, early surgery is recommended. Symptoms of entrapment include: nausea, vomiting, pain on eye movement and oculo-cardiac reflex (bradycardia, heart block, nausea, vomiting or syncope). Some patients can achieve complete resolution of their symptoms post-operatively (Egbert et al, 2000). Early diagnosis is important and early surgery is necessary to prevent EOM damage and improve prognosis

Question 37

what investigation needs to be done for a patient with suspected orbtial fracture

Answer 37

Ophthalmic Investigation
 Visual acuity
 Slit lamp examination (anterior segment & posterior segment)
 Measurement of exophthalmos / enophthalmos using a Hertle exophthalmometer or can use CT scans (Sung et al, 2013; Shah et al, 2013)
 Measurement IOP (intraocular pressure)
 FDT (Forced Duction Test)
 Electromyography/saccadic velocities
Radiological Investigations
 X-rays - readily available, but small fractures are difficult to detect and may be missed
 CT scans – more readily available than they used to be. Coronal sections are taken to determine the extent of the fracture and determine the nature of the antral soft tissue densities. CT scanning therefore allows visualisation of the EOM and soft tissues, but the CT evidence of a fracture may be minimal, they need to be carefully evaluated (Criden & Ellis, 2007)
 MRI scans – take longer and may be less readily available. Particularly useful to see herniation and entrapment more clearly

Question 38

what orthoptic investigations need to be done

Answer 38

Orthoptic investigation: Observation. Description. Documentation.

Case History
 Crucial – may be a recent history of trauma, but may be late presenting, consider events may be unwitnessed. Consider whether a head injury has also occurred.

Question 39

what symptoms would a patient with an orbital blow out fracture would they present with

Answer 39

Diplopia – note type and any changes or reversal in different gaze position
Shah et al (2013) found that herniation of soft tissue into orbital floor fracture site (in small & medium fractures only) were associated with a high risk of diplopia.
 Pain, especially on attempted eye movement
 Anaesthesia or hypoanaesthesia
 Orbital emphysema (air trapped in the orbit) – indicates a fracture of ethmoid sinuses. Patients are advised not to blow their nose post orbital fracture.
 Epistaxis (nose bleed) – advised not to blow the nose after a suspected orbital fracture.

Question 40

what signs would you see

Answer 40

Ecchymosis and oedema – lids may be closed. May need to hold lids open to test VA and examine the eye.
 Enophthalmos / exophthalmos
 Facial asymmetry – esp. in impure blow out with displacement of orbital rim
 Subconjunctival haemorrhage
 Hyphaema etc – damage to globe
 Unequal pupil sizes - sphincter muscle of iris may be damaged
 AHP as appropriate for deviation

Question 41

what would you need to look for in the investigation

Answer 41

ocular movements - looking particularly for restrictions, but may also see under and overactions

 Typically, mechanical (revise mechanical OM defects)  Restriction of elevation - orbital floor fracture
 Restriction of ABDuction - medial wall fracture
 Reversal of diplopia – from upgaze to downgaze
 Retraction of the globe
 Superior oblique defects may indicate trochlear damage
 ? tissue entrapment (see ‘trap door’ or ‘white eyed blow out’ fracture)
 ? an associated nerve palsy (see Scolozzi et al, 2022)
 ? an associated head injury as well
 General limitations of gaze are indicative of retrobulbar haemorrhage – important to consider ON function (VA, CV, CS, VEP)
 Pupil function

Question 42

what differential diagnosis needs to be done

Answer 42

soft tissue injury causes trauma to the orbit but doesn’t cause a fracture to the bone

There is commonly periorbital oedema and hypodermal bleeding, and there may be lacerations and abrasions. It is an important differential diagnosis and these patients are often seen early in the orthoptic clinic via casualty. In significant cases of oedema and haemorrhage there may be some limitation of ocular movement, but this should improve as the oedema and haemorrhage settle down. Consider whether an observation period would be helpful. Orbital imaging may be required to rule out a fracture of the orbit – is this urgent or should it wait until after a period of observation?
Soft tissue injuries can also look very similar to orbital cellulitis (a soft tissue infection of the orbit) and bacterial infections (often from sinusitis, passing from paranasal or ethmoid sinuses). In all cases there is oedema and it is possible to develop post- traumatic orbital cellulitis after an orbital injury. Orbital cellulitis and bacterial infections of the orbit are potentially life threatening and require emergency treatment with intravenous antibiotics.

Question 43

what are the surgical management options for orbital fractures

Answer 43

The aims of surgical intervention is to restore full orbital volume, restore globe movement and restore cosmesis; whilst also minimising and preventing early and late sequelae and complications.

Alinasab et al (2012) highlighted that there are differences in opinions and expertise, even within the field of specialty dealing with orbital fractures. Not all patients with an isolated orbital fracture will require surgery, but who performs surgery will vary in each hospital: Ophthalmologist – ocular plastic specialist,

Maxillofacial surgeon, ENT, Plastic surgeon – facial specialist or multidisciplinary teams. Not all surgeons will agree on whether surgery needed, type of surgery, surgical approach and the implant material to be used.

Surgical incisions and approaches
* Subciliary or subciliary extended laterally (if need more lateral access to the orbital rim)
* Subtarsal
* Infra orbital (eyelid approach - incision made along the inferior orbital margin
dissecting the orbicularis from the periosteum)

• Caldwell-Luc approach (through the maxillary antrum, between the canine and second molar teeth)
• Transconjunctival approach (through the inferior fornix of the conjunctiva)
• Endonasal approach (through the nose)
• Endoscopic approaches may also be used as they are considered safe and
  effective (Cheung et al, 2013)

Question 44

what materials are used for implants

Answer 44

An orbital blow out fracture may require repair, particularly if there is a significant defect in the orbital floor causing entrapment or significant enophthalmos. Various biomaterials are available, including autogenous graft material (bone or cartilage), a variety of alloplastic graft materials (silicon, Teflon, rubber, methacrylate, supramid, polyethylene and titanium (plate / mesh) and allogeneic graft materials (from a genetically non-identical individual from the same species). A systematic review has shown all materials are successful to variable degrees (Gunarajah & Samman, 2013) but it has been suggested recently that Silastic sheets are associated with a higher rate of complications (Moon et al, 2014). There is also no evidence so far of a long- term benefit of one implant material type over another (Baek et al, 2014). See also Dubois et al (2015) for a review.
With the advances in 3D modelling and 3D printing it is hoped that the planning of surgery and the development or personalised orbital implants can improve surgical accuracy and outcomes (Cui et al, 2014). However, results using both surgical techniques are thought to be comparable (Maher et al, 2022). Currently ‘bespoke’ orbital implants (or patient specific implants) are reserved for more complex fracture repairs. These are unlikely to be available as ‘standard clinical care’ in all centres you will visit.

Question 45

what are complications for surgical intervention

Answer 45

Migration of the implant used in reconstruction - ‘extrusion’, which may occur later
Infection – consider the mechanism of injury, most surgeons routinely prescribe antibiotics post-op (Courtney et al, 2000)
Ectropion - lower eyelid turns outwards
OM restriction and persistent diplopia
Lower eyelid oedema
Retrobulbar haematoma (rare) (Cheon et al, 201)

Question 46

when is late surgical intervention advised

Answer 46

Late orbital fracture repair is usually reserved for cases of significant enophthalmos where it is persistent / progressive.

EOM surgery is undertaken later in cases of significant diplopia / motility problems, often in depression & primary position, there may have also been a neurogenic palsy / myogenic damage to IR. It needs to be considered if there was a previous fracture repair or not - diplopia post fracture repair may improve with time and some patients may have residual diplopia relating to orbital implant / neurogenic / mechanical defect (Loba et al, 2012). Imaging may again prove useful in these cases.