Orbits Flashcards
1
Q
What are the structures making up the roof of the orbit?
A
The lesser wing of the sphenoid
and the orbital plate of the frontal bone.
2
Q
What might a defect in the orbital roof cause?
A
pulsatile proptosis due to transmission of cerebrospinal fluid pulsation to the orbit.
3
Q
What are the structures making up the lateral wall of the orbit?
A
the greater wing of the sphenoid and the zygomatic.
4
Q
What are the structures making up the floor of the orbit?
A
three bones: the zygomatic, maxillary and palatine.
5
Q
What are the structures making up the medial wall of the orbit?
A
four bones: maxillary, lacrimal,
ethmoid and sphenoid. The lamina papyracea, which forms
part of the medial wall, is paper-thin and perforated by numerous foramina for nerves and blood vessels
6
Q
What sinusitis is orbital cellulitis most likely secondary to?
A
ethmoidal sinusitis due to paper thin wall and orbital connection
7
Q
What structures pass through the SOF?
A
○ The superior portion contains the lacrimal, frontal and trochlear nerves and the superior ophthalmic vein.
○ The inferior portion contains the superior and inferior divisions of the oculomotor nerve, the abducens and nasociliary nerves and sympathetic fibres from the cavernous plexus.
8
Q
What is Tolosa-Hunt syndrome?
A
Inflammation of the superior orbital fissure and apex (Tolosa–Hunt syndrome) may therefore result in a multitude of signs including ophthalmoplegia and venous
outflow obstruction
9
Q
What structures pass through the IOF?
A
the maxillary nerve, the zygomatic nerve and branches of the
pterygopalatine ganglion, as well as the inferior ophthalmic vein.
10
Q
What is the length of the intraorbital portion of the optic nerve?
A
25mm
11
Q
What conditions cause axial proptosis?
A
space-occupying lesions within the muscle cone such as a cavernous haemangioma or optic nerve tumours
cause axial proptosis
12
Q
What conditions cause proptosis and dystopia?
A
extraconal lesions
13
Q
What is dystopia?
A
displacement of the globe in the coronal plane, usually due to an extraconal orbital mass such as a
lacrimal gland tumour
14
Q
What measurements on exophthalmometry indicate exophthalmos?
A
20mm or more or a difference between the 2 eyes 2-3mm
15
Q
What are the causes of pseudoproptosis?
A
(the false impression of proptosis) may be due to facial asymmetry, enlargement of the globe (e.g.
high myopia or buphthalmos), lid retraction or contralateral
enophthalmos.
16
Q
What is enophthalmos and list some causes?
A
implies recession of the globe within the orbit. Causes include congenital and traumatic orbital wall abnormali-
ties, atrophy of the orbital contents (e.g. radiotherapy, scleroderma,
chronic eye poking in blind infants – the ‘oculodigital’ sign) or
sclerosis (e.g. metastatic scirrhous carcinoma, sclerosing orbital
inflammatory disease).
17
Q
What tests can differentiate a restrictive from neurological motility defect?
A
Forced duction test
Differential IOP test
Saccadic eye movements
18
Q
What is the forced duction test?
A
Under topical anaesthesia, the insertion of the muscle in an involved eye is grasped with forceps and the
globe rotated in the direction of reduced mobility. Checked
movement of the globe indicates a restrictive problem. No resistance will be encountered with a neurological lesion.
19
Q
What is the differential IOP test?
A
The IOP is measured in the primary position of gaze and then with the patient attempting to look in
the direction of limited mobility. An increase of 6 mmHg or more denotes resistance transmitted to the globe by muscle restriction (the Braley sign).
20
Q
What is the saccadic eye movements test?
A
in neurological lesions are reduced
in velocity, while restrictive defects manifest normal saccadic velocity with sudden halting of ocular movement.
21
Q
What is a bruit?
A
a sign found with a larger carotid–cavernous fistula. It is best heard with the bell of the stethoscope and is lessened or abolished by gently compressing the ipsilateral carotid
artery in the neck
22
Q
What is a pulsation?
A
caused either by an arteriovenous communication or a defect in the orbital roof. In the former, pulsation
may be associated with a bruit depending on the size of the
communication. In the latter the pulsation is transmitted from
the brain by the cerebrospinal fluid and there is no associated
bruit. Mild pulsation is best detected on the slit lamp, particularly by applanation tonometry.
23
Q
What is optic atrophy?
A
may be preceded by swelling,
is a feature of severe compressive optic neuropathy. Important
causes include thyroid eye disease and optic nerve tumours.
24
Q
What are opticociliary collaterals?
A
consist of enlarged pre-existing peri-
papillary capillaries that divert blood from the central retinal venous circulation to the peripapillary choroidal circulation when there is obstruction of the normal drainage channels
The collaterals may be associated with any orbital or optic nerve tumour that compresses the intraorbital optic nerve and impairs blood flow through the central retinal vein. The most common tumour associated with shunts is an optic nerve sheath meningioma but they may also occur with optic nerve glioma, central retinal vein occlusion, idiopathic intracranial hypertension and glaucoma.
25
What is Orbital CT good for?
1) Depicting bony structures
2) Location and size of space-occupying lesions.
3) Small fractures
4) Foreign bodies
5) Blood
6) Herniation of EOM and emphysema
7) Confirm an orbital abscess
26
What is MRI orbits good for?
1) Orbital apex lesions
2) Intracranial extension of tumours
3) Useful for monitoring inflammatory disease
4) STIR scans for TED
27
What tumour does opticociliary shunt vessels on the disc commonly represent?
Optic nerve sheath meningioma
28
What is the pathophysiology of Graves disease?
an autoimmune disorder
in which IgG antibodies bind to thyroid stimulating hormone
(TSH) receptors in the thyroid gland and stimulate secretion of
thyroid hormones.
29
What is the major risk factor to develop TED once a patient has Graves disease?
Smoking
30
What can radioactive iodine do to TED?
Worsen it
31
What is the pathophyisology of TED?
Organ-specific autoimmune
reaction in which an antibody that reacts against thyroid gland cells and orbital fibroblasts leads to inflammation of extraocular muscles, interstitial tissues, orbital fat and lacrimal glands characterized by pleomorphic cellular infiltration, associated with increased secretion of glycosaminoglycans and osmotic imbibition of water.
There is an increase in the volume of the orbital contents, particularly the muscles, which can swell to eight times their normal size. There may be a secondary elevation of intraorbital
pressure, and the optic nerve may be compressed. Subsequent degeneration of muscle fibres eventually leads to fibrosis, which exerts a tethering effect on the involved muscle, resulting in
restrictive myopathy and diplopia
32
Stages of TED?
Congestive (Inflammatory) stage in which eyes are red and painful. Remits in 1-3 years. Only 10% develop serious long term problems
Quiescent stage in which eyes white but painless motility defect may be present
33
What are some clinical features of TED?
(i) soft tissue involvement,
(ii) lid retraction,
(iii) proptosis,
(iv) optic neuropathy
(v) restrictive myopathy.
34
What is the EUGOGO classification and elaborate on it?
1) sight-threatening due to optic neuropathy or corneal breakdown;
2) moderate–severe, with one of moderate–severe soft tissue involvement, lid retraction of 2 mm or more, diplopia and proptosis of 3 mm or more;
3) mild, with only a minor impact on
daily life.
35
What is lid retraction?
Retraction of upper and lower lids occurs in about 50% of patients
with Graves disease. Overaction of Müller muscle is postulated to
occur as a result of sympathetic overstimulation secondary to high
levels of thyroid hormones.
36
What is Dalrymple sign?
moderate bilateral asymmetrical lid retraction
37
What is Kocher sign?
severe bilateral lid retraction
38
What is von-Graefe sign?
lid lag on downgaze
39
What % of TED patients develop ophthalmoplegia which may be permanent?
Between 30% and 50% of patients
40
Motility defects in the order of frequency in TED?
○ Elevation defect caused by fibrotic contracture of the inferior rectus, may mimic superior rectus palsy and
is the most common motility deficit.
○ Abduction defect due to fibrosis of the medial rectus, which may simulate sixth nerve palsy.
○ Depression defect secondary to fibrosis of the superior rectus.
○ Adduction defect caused by fibrosis of the lateral rectus.
41
What % of patients with TED get optic neuropathy?
(up to 6%)
42
Does proptosis need to be present for optic nerve compression?
compression of the optic nerve
secondary to enlarged and congested rectus muscles may occur in the absence of proptosis.
43
How to assess for optic neuropathy in TED?
○ Visual acuity (VA) is usually reduced, but not invariably.
○ Colour desaturation is a sensitive feature.
○ There may be diminished light brightness appreciation.
○ A relative afferent pupillary defect, if present, should give cause for marked concern.
○ Visual field defects can be central or paracentral and may be combined with nerve fibre bundle defects. These findings, in concert with elevated IOP, may be confused with primary open-angle glaucoma.
○ The optic disc may be normal, swollen or, rarely, atrophic.
44
How to manage mild TED?
○ Lubricants for SLK, corneal exposure and dryness.
○ Topical anti-inflammatory agents (steroids, (NSAIDs), ciclosporin) are advocated by some authorities.
○ Head elevation with three pillows during sleep to reduce periorbital oedema.
○ Eyelid taping during sleep may alleviate mild exposure keratopathy.
45
How to manage moderate TED?
○ Systemic steroids are the mainstay of treatment for moderate–severe disease. Oral prednisolone 60–80 mg/day may be given initially and tapered depending on response.
Intravenous methylprednisolone is often reserved for acute compressive optic neuropathy, but tolerability is better, and outcomes may be superior, compared with oral treatment.
A lower-intensity regimen
in the absence of acute sight-threatening disease is 0.5 g once weekly for 6 weeks followed by 0.25 g once weekly for 6 weeks. A reduction in discomfort, chemosis and periorbital oedema usually occurs within 24 hours, with a maximal response within 2–8 weeks. Ideally, oral steroid therapy should be discontinued after several months, but long-term low-dose maintenance may be necessary.
○Orbital steroid injections are occasionally used in selected cases to minimize systemic side effects, but are typically considerably less effective than systemic treatment.
○ Low-dose fractionated radiotherapy. A positive response is usually evident within 6 weeks, with maximal improvement by 4 months; around 40% will not respond.
○Combined therapy with irradiation, azathioprine and low-
dose prednisolone may be more effective than steroids or
radiotherapy alone.
46
When is orbital wall decompression useful in TED?
if steroids are ineffective (20% receiving intravenous treatment) or
contraindicated. Orbital radiotherapy may also be administered, but is generally only used as an adjunct to other modalities.
47
What steroid regimen is a good idea for Optic neuropathy?
Pulsed intravenous methylprednisolone is commonly used, regimens including 0.5–1 g on 3 successive days with conversion to
oral treatment (e.g. 40 mg/day prednisolone) or 0.5–1 g
on alternate days, 3–6 times, keeping the maximum dose below 8 g to reduce the risk of liver compromise, followed by oral prednisolone.
48
What monoclonal disease modifying drug is useful in TED?
monoclonal antibody treatment with rituximab and teprotumumab. Teprotumumab is an inhibitor of insulin-like growth factor 1 receptor (IGF-1R) and is effective in reducing proptosis and the Clinical Activity Score in patients with TED.
49
How can the proptosis be treated once the inflammation has remitted in TED?
the patient can be left with cosmetically and functionally
significant proptosis, the treatment of which is essentially surgical. Surgical decompression increases the volume
of the orbit by removing the bony walls and may be combined with removal of orbital fat.
50
How many walls are decompressed in TED proptosis?
Most surgery is undertaken via an external approach, though the medial
wall and the medial part of the floor can be reached endoscopically. One-wall (deep lateral) decompression is
effective (approximately 4–5 mm reduction in proptosis) and may reduce the risk of postoperative diplopia
Two-wall (balanced medial and lateral) decompression provides a greater effect but with a significant risk of inducing diplopia
Three-wall decompression includes the floor with a reduction in proptosis of 6–10 mm but may lead to hypoglobus and carries a higher risk of infraorbital nerve damage and diplopia. Very severe proptosis may
require removal of part of the orbital roof in addition (four-wall decompression).
51
When is surgery for restrictive myopia performed in TED?
provided the inflammatory stage has
subsided and the angle of deviation has been stable for at least 6–12 months.
52
What type of muscle surgery is commonly performed in TED?
Recession of the inferior and/or medial recti is the most commonly indicated surgery (a rectus muscle is never resected, only recessed
in TED), generally utilizing adjustable sutures .
The suture is adjusted later the same day or on the first postoperative day to achieve optimal alignment and the
patient is encouraged subsequently to practise achieving single vision with a consistently accessible target such as a television.
53
How can lid retraction be treated in TED?
1) Mild lid retraction frequently improves spontaneously
2) Control of hyperthyroidism
3) Botulinum toxin injection to the levator aponeurosis and Müller
muscle may be used as a temporary measure in patients awaiting definitive correction.
54
What organisms are typically responsible for preseptal cellulitis?
Staphylococcus aureus and Streptococcus pyogenes,
55
Difference between preseptal and orbital cellulitis
in contrast to orbital cellulitis, proptosis and chemosis are absent and VA, pupillary reactions and ocular motility are unimpaired. The
patient is often pyrexial.
56
Treatment for preseptal cellulitis?
oral antibiotics such as co-amoxiclav
250–500 mg/125 mg 2–3 times daily or 875/125 mg twice daily,
depending on severity. Severe infection may require intravenous antibiotics. The patient’s tetanus status should be ascertained in
cases following trauma.
57
Which pathogens cause orbital cellulitis?
Streptococcus pneumoniae, Staphylococcus aureus,
Streptococcus pyogenes
and Haemophilus influenzae
58
How does orbital cellulitis actually happen?
infection originating typically from the paranasal (especially ethmoid) sinuses. Infection can also spread from preseptal cellulitis, dacryocystitis, midfacial skin or dental infection and can follow trauma, including any form of ocular surgery. Blood-borne spread from infection elsewhere in the body may occur
59
Differential diagnoses for orbital cellulitis?
Infection
*Bacterial orbital cellulitis
*Fungal orbital infection
*Dacryocystitis
*Infective dacryoadenitis
Vascular lesions
*Acute orbital haemorrhage
*Cavernous sinus thrombosis
*Carotid–cavernous fistula Neoplasia
*Rapidly progressive retinoblastoma
*Lacrimal gland tumour
*Other neoplasm, e.g. metastatic lesion with inflammation, lymphoma, Waldenström macroglobulinaemia
*Rhabdomyosarcoma, leukaemia, lymphangioma or neuroblastoma in children
Endocrine
*Thyroid eye disease of rapid onset
Non-neoplastic inflammation
*Idiopathic orbital inflammatory disease
*Tolosa–Hunt syndrome
*Orbital myositis
*Acute allergic conjunctivitis with lid swelling
*Herpes zoster ophthalmicus
*Herpes simplex skin rash
*Sarcoidosis
*Vasculitides: granulomatosis with polyangiitis, polyarteritis nodosa
*Scleritis, including posterior scleritis
*Ruptured dermoid cyst
60
How to investigate orbital cellulitis?
*Ascertainment of tetanus immunization status in cases of
trauma.
*White cell count.
*Blood cultures.
*Culture of nasal discharge.
*High-resolution CT of the orbit, sinuses and brain is vital to confirm the diagnosis and exclude a subperiosteal or intracranial abscess. MRI is also sometimes performed.
*Lumbar puncture if meningeal or cerebral signs develop.
61
How to treat orbital cellulitis?
*Hospital admission is mandatory, with urgent ENT assessment and frequent ophthalmic review.
Paediatric specialist advice should be sought in the management of
a child and a low threshold should be adopted for infectious disease specialist consultation.
* Delineation of the extent of erythema on the skin using a
surgical marker may help in judging progress.
* Antibiotics are given intravenously, with the specific drug depending on local sensitivities. Ceftazidime is a typical choice, supplemented by oral metronidazole to cover anaerobes. Intravenous antibiotics should be continued until the patient has been apyrexial for 4 days, followed by 1–3 weeks of oral treatment.
62
What is Rhino-orbital Mucormycosis and which population of people does it tend to affect?
a rare aggressive and often fatal infection caused by fungi of the family Mucoraceae. It typically affects patients with diabetic ketoacidosis or immunosuppression and is extremely rare in the immunocompetent
63
How does rhino-orbital mucormycosis spread to the orbits?
Infection is acquired by the inhalation
of spores, which give rise to an upper respiratory infection. Spread then occurs to the contiguous sinuses and subsequently to the orbit and brain. Invasion of blood vessels by the hyphae results in occlusive vasculitis with infarction of orbital tissues.
64
How to investigate rhino-orbital mucormycosis
*Ascertainment of tetanus immunization status in cases of
trauma.
*White cell count.
*Blood cultures.
*Culture of nasal discharge.
*High-resolution CT of the orbit, sinuses and brain is vital to confirm the diagnosis and exclude a subperiosteal or intracranial abscess. MRI is also sometimes performed.
*Lumbar puncture if meningeal or cerebral signs develop.
65
What are some symptoms and signs of rhino-orbital mucormycosis
* Symptoms. Gradual onset facial and periorbital swelling, diplopia and visual loss.
* Signs are similar to bacterial orbital cellulitis, but tend to be less acute and with slower progression. Infarction superimposed on septic necrosis is responsible for the classic black eschar that may develop on the palate, turbinates, nasal septum, skin
and eyelids
66
What is the treatment for rhino-orbital mucormycosis
* Correction of the underlying metabolic defect should be instituted if possible.
* Intravenous antifungal treatment.
* Daily packing and irrigation of the involved areas with anti-
fungal agent.
* Wide excision of devitalized and necrotic tissues. Exenteration
may be required in unresponsive cases in order to reduce the
risk of death.
* Adjunctive hyperbaric oxygen may be helpful.
67
Histopathological diagnosis of NSOI/orbital pseudotumour?
pleomorphic inflammatory cellular infiltration followed by reactive fibrosis.
68
What are some symptoms and signs of NSOI?
acute or subacute ocular and
periocular redness, swelling and pain
*Signs
○ Pyrexia is present in up to 50% of children, but is rare in adults.
○ Congestive proptosis.
○ Mild to severe ophthalmoplegia may occur.
○ Features of optic nerve dysfunction, particularly if the inflammation involves the posterior orbit. There may be optic disc swelling.
○ Choroidal folds, if present, may be associated with reduced vision but optic neuropathy must always be suspected.
69
What is the course of NSOI?
Variable
○ Spontaneous remission after a few weeks without sequelae.
○ Intermittent episodes of activity, usually with eventual remission.
○ Severe prolonged inflammation eventually leading to progressive fibrosis of orbital tissues, resulting in a ‘frozen orbit’ characterized by ophthalmoplegia, which may be
associated with ptosis and visual impairment caused by optic nerve involvement.
70
How to investigate NSOI?
○CT shows ill-defined orbital opacification and loss of
definition of contents
○Biopsy is generally required in persistent cases to confirm
the diagnosis and particularly to rule out neoplasia and systemic inflammatory conditions.
○A wide range of other investigations may be considered to aid in the exclusion of alternative diagnoses, particularly infection, lymphoma and non-neoplastic infiltrative disorders such as sarcoidosis and Wegener granulomatosis.
71
How to treat NSOI?
* Observation, for relatively mild disease, in anticipation of
spontaneous remission.
*NSAIDs alone (e.g. ibuprofen) are often effective and may be tried in mild disease prior to steroid therapy. Co-prescription of a proton pump inhibitor should be considered.
*Systemic steroids should be administered only after the
diagnosis has been confirmed, as they may mask other pathology such as infection and Wegener granulomatosis. Oral prednisolone is initially given at a dose of 1.0–1.5 mg/kg/day, subsequently being tapered and discontinued over a number of weeks depending on clinical response.
*Radiotherapy may be considered if there has been no improvement after 2 weeks of adequate steroid therapy.
72
What is orbital myositis and what does histology show?
an idiopathic, non-specific inflammation of one or more extraocular muscles and is considered a subtype of IOID. Histology shows a chronic inflammatory cellular infiltrate
associated with the muscle fibres
73
What are some symptoms and signs of Orbital myositis?
*Symptoms. Acute pain, exacerbated by eye movement and diplopia. Onset is usually in early adulthood.
*Signs are generally less obvious than NSOI
○Lid oedema, ptosis and chemosis.
○Pain and diplopia associated with eye movements.
○Vascular injection over the involved muscle
○In chronic cases fibrosis of the affected muscle may occur with permanent restrictive myopathy.
74
What is the course of Orbital myositis?
○Acute non-recurrent involvement that resolves spontaneously within 6 weeks.
○Chronic disease characterized by either a single episode persisting for longer than 2 months (often for years) or recurrent attacks.
75
How is orbital myositis investigated?
primarily of MRI or CT, which show
enlargement of the affected muscles, with or without involvement of the tendons of insertion. This is in
contrast to TED-related muscle enlargement, in which the tendon is always spared. Additional investigations may be required in some cases.
76
How is orbital myositis treated?
Treatment is aimed at relieving discomfort and dysfunction,
shortening the course and preventing recurrences. NSAIDs may be adequate in mild disease, but systemic steroids are generally required and usually produce dramatic improvement, although recurrence is seen in 50%. Radiotherapy is also effective, particularly in limiting recurrence.
77
What are the causes of acute dacryoadenitis?
idiopathic or due to viral (e.g. mumps, Epstein–Barr, cytomegalovirus) or – rarely – bacterial infection
78
How does acute dacryoadenitis present?
There is tenderness over the lacrimal gland and injection of the conjunctiva overlying the palpebral lobe may be
seen on upper lid eversion
79
What is Tolosa- Hunt syndrome?
rare idiopathic condition caused by
non-specific granulomatous inflammation of the cavernous sinus,
superior orbital fissure and/or orbital apex.
80
How does Tolosa- Hunt syndrome present?
Presentation is with
ipsilateral periorbital or hemicranial pain and diplopia due to
ocular motor paresis, with pupillary and eyelid involvement in
many cases. Proptosis, if present, is usually mild. Sensory loss along
the distribution of the first and second divisions of the trigeminal
nerve is common.
81
How is Tolosa Hunt syndrome treated and what is its clinical course?
systemic steroids and other immunosuppressants as necessary; the clinical course is characterized by remissions and recurrences.
82
What is Granulomatosis with polyangiitis?
an idiopathic multisystem granulomatous disorder that may involve the orbit, often bilaterally,
usually by contiguous spread from the paranasal sinuses or
nasopharynx.
83
How is GPA treated?
cyclophosphamide
and steroids, which are usually effective. In resistant cases ciclosporin, azathioprine, antithymocyte globulin or plasmapheresis
may be useful. Surgical decompression may be required for severe orbital involvement.
84
What is cavernous sinus thrombosis?
refers to clotting within the cavernous sinus, usually resulting from infection such as sinusitis, orbital or preseptal cellulitis or otitis.
85
What are the features of cavernous sinus thrombosis?
rapid onset and may include severe headache, malaise, nausea and vomiting, unilateral or often
bilateral proptosis, chemosis, congestion of the facial, conjunctival
and retinal veins, reduced vision and signs resulting from compromised function of the third to sixth cranial nerves, which run through the cavernous sinus.
86
How is cavernous sinus thrombosis investigated?
MRI and MRI venography.
Systemic investigation for infection is
also performed, including lumbar puncture.
87
How is cavernous sinus thrombosis treated?
consists of intravenous antibiotics and sometimes surgical drainage.
88
What is a carotid- cavernous fistula?
involves the development of an
arteriovenous fistula between the carotid artery and the venous cavernous sinus with a rise in venous pressure in the sinus and structures draining to it
89
What is a direct carotid- cavernous fistula?
high-flow shunts in which carotid artery blood passes directly into the cavernous sinus through a defect
in the wall of the intracavernous portion of the internal carotid
artery as a result of trauma (75%), including surgery, spontaneous rupture of an intracavernous carotid aneurysm or an atherosclerotic artery, the latter frequently in a middle-aged
hypertensive woman; spontaneous fistulae usually have lower flow.
90
What is an indirect carotid- cavernous fistula?
the intracavernous portion of the internal carotid artery remains intact. Arterial blood flows through the meningeal branches of the external
or internal carotid arteries indirectly into the cavernous sinus and the clinical features are subtler than in a direct fistula such that the condition may be overlooked. Spontaneous rupture of an atherosclerotic artery or of a congenital malformation is the usual cause and may be precipitated by minor trauma or straining. Connective tissue and collagen vascular disorders can be associated.
91
What are the symptoms of direct carotid-cavernous fistula?
Presentation may be days or weeks after head injury with a classic triad of pulsatile proptosis, conjunctival chemosis and a whooshing noise in the head.
92
What are the symptoms of indirect carotid-cavernous fistula?
Gradual onset of redness of one or both eyes is a typical presentation, caused by conjunctival vascular
engorgement.
93
What are the signs of a direct carotid-cavernous fistula?
○Immediate visual loss may be due to ocular or optic nerve damage at the time of head trauma.
○Delayed visual loss may occur as a result of exposure keratopathy, secondary glaucoma, central retinal vein occlusion, anterior segment ischaemia or ischaemic optic
neuropathy.
○Signs are usually ipsilateral to the fistula but may be bilateral, or even contralateral, because of midline connections between the two cavernous sinuses.
○Marked epibulbar vascular dilatation
○Chemosis, commonly haemorrhagic, particularly in the early stage
○ Pulsatile proptosis associated with a bruit and a thrill, both of which can be abolished by ipsilateral carotid compression in the neck
○Increased IOP due to elevated episcleral venous pressure and orbital congestion and sometimes angle closure glaucoma.
○Anterior segment ischaemia, characterized by corneal epithelial oedema, aqueous cells and flare and in severe cases iris atrophy, cataract and rubeosis iridis.
○Ptosis due to third nerve involvement.
○ Ophthalmoplegia (60–70%) due to the ocular motor nerve damage from initial trauma, an intracavernous aneurysm or the fistula itself.
○ Fundus examination may show optic disc swelling, venous dilatation and intraretinal haemorrhages from venous stasis and impaired retinal blood flow.
94
What are the signs of an indirect carotid-cavernous fistula?
○Milder epibulbar vascular dilatation than with a direct fistula
○Exaggerated ocular pulsation, which is readily detected on slit lamp applanation tonometry.
○The presence of ‘corkscrew’ epibulbar vessels is a common subtle later sign. These are not pathognomonic and can be found in normal eyes.
○Raised IOP, often bilateral but higher on the side of the fistula.
○Proptosis and bruit are mild if present.
○Ophthalmoplegia caused by sixth nerve palsy or swelling of extraocular muscles in marked cases.
○Fundus may be normal or manifest moderate venous dilatation, with later tortuosity as with corkscrew conjunctival vessels, this is not pathognomonic
95
How to investigate suspected carotid-cavernous fistula?
CT and MRI may demonstrate prominence of
the superior ophthalmic vein and diffuse enlargement of extraocular muscles, though these may only be visible with a direct fistula. Orbital
Doppler imaging may show abnormal flow patterns, particularly in the superior orbital vein. Definitive diagnosis may involve selective catheter digital subtraction angiography, especially in mild dural fistulae, though CT and MRI angiography can be useful.
96
How is direct carotid cavernous fistula treated?
Most carotid–cavernous fistulae are not life-threatening
Surgery is indicated if spontaneous closure does not occur. A post-traumatic fistula is much less likely to close on its own than a spontaneous fistula because of higher blood flow.
Treatment is likely to consist of a transarterial approach to repair the artery eg coil or occlude the involved sinus (e.g. coil, balloon). Craniotomy for arterial repair is occasionally
needed.
97
How is indirect carotid cavernous fistula treated?
If required, treatment usually involves transvenous occlusion of the involved sinus. Spontaneous closure or occluding thrombosis sometimes (up to 50%) occurs. Intermittent carotid compression under specialist supervision has been reported to increase the likelihood that this will take place.
98
What is a Dacryops and how is it treated?
a frequently bilateral cyst of the lacrimal gland that is thought to develop from a dilated obstructed duct. A round cystic lesion protrudes into the superior fornix from the palpebral lobe of the gland and may present with inflammation
Treatment involves excision or marsupialization, with histopatho-
logical analysis.
99
What is a dermoid cyst?
An orbital dermoid cyst is a choristoma (a mass of histologically
normal tissue in an abnormal location) derived from displacement of ectoderm to a subcutaneous location along embryonic lines of closure
100
Symptoms of dermoid cyst?
Dermoid cysts are one of the most frequently encountered orbital
tumours in children.
*Symptoms
○A superficial orbital dermoid cyst presents in infancy with a painless nodule, most commonly located in the
superotemporal and occasionally the superonasal part of the orbit.
○A deep dermoid cyst presents in adolescence or adult life with a gradually increasingly protruding eye, or acutely with an inflamed orbit due to rupture.
101
Signs of dermoid cyst?
○Superficial: a firm round smooth non-tender mass 1–2 cm
in diameter, mobile under the skin but usually tethered to the adjacent periosteum. The posterior margins
are easily palpable, denoting a lack of deeper origin or extension.
○Deep: proptosis, dystopia or a mass lesion with indistinct posterior margins
102
What is a good tip when removing a dermoid cyst?
take care not to rupture the wall of the cyst, as this can cause a granulomatous inflammation in the surrounding tissue.
102
How to investigate dermoid cyst?
○ Superficial: imaging shows a well-circumscribed heterogeneous cystic lesion
○Deep: imaging again shows a well-circumscribed lesion. Some deep dermoids, associated with bony
defects, may extend into the inferotemporal fossa or intracranially
103
What is a sinus mucocoele?
develops when the drainage of normal paranasal sinus secretions is obstructed due to infection, allergy, trauma, tumour or congenital narrowing.
A slowly expanding cystic accumulation of mucoid secretions and epithelial debris develops and gradually erodes the bony walls of
the sinus, causing symptoms by encroachment upon surrounding
tissues.
104
What is an Encephalocoele?
is formed by herniation of intracranial contents through a congenital defect of the base of the skull and can be located at the front or back of the head.
105
Meningocoele vs meningoencephalocoele?
A meningocoele contains only dura whilst a meningoencephalocoele also contains brain tissue.
106
What is posterior orbital encephalocoele associated with?
NF 1
107
What are primary orbital varices?
(combined venous–lymphatic malformations of the orbit) consist of a plexus of thin-walled distensible low-flow vein-like vessels that are commonly, though not always, intrinsic to the normal circulation.
108
What is a hamartoma?
a disorganized overgrowth of mature tissues normally present in the involved area
109
What are some associations of primary orbital varices?
Varices of the eyelids and conjunctiva
110
Where are primary orbital varices found?
Most cases are unilateral and the most frequent site is upper nasal.
111
What are the signs of primary orbital varices?
Intermittent non-pulsatile proptosis without a bruit is reported. If there is free communication with the normal circulation, reversible proptosis may be precipitated or accentuated by increasing venous pressure through coughing, straining, the Valsalva manoeuvre
112
What is the treatment for primary orbital varices?
Small lesions generally do not require treatment. Surgical excision is technically difficult and often incomplete because the lesions
are friable and bleed easily. It can be complicated by severe orbital
haemorrhage and vascular optic nerve compromise.
Specialized techniques such as embolization and carbon dioxide laser surgery may be helpful adjuncts. Indications include recurrent thrombosis, pain, severe proptosis and optic nerve compression
113
What is lymphangioma?
a rare hamartomatous vascular tumour that tends to enlarge and infiltrate diffusely with time. Some authorities believe lymphangiomas to be a variant of venous orbital
anomaly (varices) across a single spectrum and the term ‘combined venous–lymphatic malformations of the orbit’ has been suggested
Although usually isolated from the main circulation, bleeding into the lumen may occur with subsequent formation of blood-filled ‘chocolate cysts’ that regress spontaneously with
time.
114
What are the symptoms/signs of lymphangioma?
Anterior lesions typically manifest as several soft bluish masses in
the upper nasal quadrant
Posterior lesions may cause slowly progressive proptosis, or
initially may lie dormant and later present with the sudden onset
of painful proptosis secondary to spontaneous haemorrhage, which may be associated with optic nerve compression. Involvement of the lids, conjunctiva and oropharynx may be
seen; intracranial lesions may also be present.
115
What is the treatment for lymphangioma?
In many cases the visual prognosis is good without treatment.
Surgical excision is difficult because lesions are not encapsulated,
friable, bleed easily and commonly infiltrate normal orbital tissues; repeated subtotal excision may be necessary. Persistent sight-threatening chocolate cysts can be drained or removed sub-totally by controlled vapourization using a carbon dioxide laser.
116
What is the most common tumour of the orbit and periorbital area in childhood?
Capillary haemangioma
117
What kind of -oma is a capillary haemangioma?
Hamartoma
118
What is Kasabach- Merrit Syndrome?
Large or multiple lesions (capillary haemangiomas) may have associated visceral involvement, which can lead to serious complications such as thrombocytopenia
119
What is the incidence of capillary haemagioma in the general population?
5%
120
What are the symptoms and signs of capillary haemangioma?
* Symptoms. The lesion is usually noticed by the parent, usually
in the first few months of life. Approximately 30% are present
at birth.
* Signs. Extensive underlying orbital involvement should always be ruled out in a seemingly purely superficial lesion:
○ A superficial cutaneous lesion (‘strawberry naevus’) is bright red
○ Preseptal (deeper) tumours appear dark blue or purple through the overlying skin
○ A large tumour may enlarge and change in colour to a deep blue during crying or straining, but both pulsation and a bruit are absent.
121
How to investigate suspected capillary haemangioma?
Imaging is generally performed for other than very small lesions, mainly to rule out more extensive orbital
disease. Ultrasound shows medium internal reflectivity and on MRI or CT the lesion appears as a soft tissue mass in the anterior orbit or as an extraconal mass with finger-like
posterior expansions
The orbital cavity may show
enlargement but there is no bony erosion.
122
What is the treatment for capillary haemangioma?
Treatment is indicated principally for amblyopia secondary to induced astigmatism, anisometropia, occlusion or strabismus and less commonly for
cosmesis, optic nerve compression or exposure keratopathy.
*Beta-blockers. Oral propranolol is now widely used. The prescription and monitoring should generally be carried out by a paediatrician. Topical preparations including timolol are equally effective, with excellent longterm results and no systemic side effects
*Steroids
Injection of triamcinolone acetonide or betamethasone into a cutaneous or preseptal tumour is usually effective in early lesions.
*Laser may be used to close blood vessels in superficial skin lesions less than 2 mm in thickness.
*Interferon alfa-2a and vincristine may be used for some steroid-resistant sight-threatening lesions.
*Local resection with cutting cautery or carbon dioxide laser may reduce the bulk of an anterior circumscribed tumour, but is usually reserved for the late inactive stage unless a resistant
tumour is sight- or life-threatening.
123
What is the course of capillary haemangioma?
rapid growth 3–6 months after diagnosis, followed by a slower phase
of natural resolution in which 30% of lesions resolve by the age of 3 years and about 75% by the age of 7.
124
What is a cavernous haemangioma?
occurs in middle-aged adults, with a
female preponderance of 70%. The growth may be accelerated by
pregnancy. It is the most common orbital tumour in adults and is
probably a vascular malformation rather than a neoplastic lesion.
Although it may develop anywhere in the orbit, it most frequently occurs within the lateral part of the muscle cone just behind the globe and behaves like a low-flow arteriovenous malformation.
125
What are the symptoms and signs of cavernous haemangioma?
* Symptoms. Slowly progressive unilateral proptosis; bilateral
cases are very rare.
*Signs
○ Axial proptosis which may be associated with optic disc oedema and choroidal folds.
○ A lesion at the orbital apex may compress the optic nerve without causing significant proptosis. Gaze-evoked transient blurring of vision may occur.
○ There may be impairment of extraocular muscle excursion.
126
What does histology of cavernous haemangioma show?
congested variably sized endothelial-lined vascular channels separated by fibrous septa
127
How to investigate suspected cavernous haemangioma?
CT and MRI show a well circumscribed oval lesion, usually within the muscle cone. There is only slow contrast enhancement. Ultrasound is also useful.
128
What is the treatment for cavernous haemangioma?
Many cavernous haemangiomas are detected by chance on scans performed for unrelated reasons and observation alone is often appropriate.
Symptomatic lesions require surgical excision in most cases because they gradually enlarge. The cavernous haemangioma, unlike its capillary counterpart, is usually well-encapsulated and relatively easy to remove
129
What is a pleomorphic lacrimal gland adenoma?
Pleomorphic adenoma (benign mixed-cell tumour) is the most common epithelial tumour of the lacrimal gland and is derived from the ducts and secretory elements including myoepithelial cells.
130
What does histology of a pleomorphic lacrimal gland adenoma show?
the inner layer of cells forms glandular tissue that may be associated with squamous differentiation and keratin production.
The outer cells undergo metaplastic change leading to the formation of myxoid tissue.
131
What are the symptoms and signs of pleomorphic lacrimal gland adenoma?
* Symptoms. Painless slowly progressive proptosis or swelling
in the superolateral eyelid, usually of more than a year’s duration. Old photographs may reveal an abnormality many years prior to presentation.
*Signs
○Orbital lobe tumour presents as a smooth, firm, non- tender mass in the lacrimal gland fossa with inferonasal
dystopia. Posterior extension may cause proptosis, ophthalmoplegia and choroidal folds.
○ Palpebral lobe tumour is less common and tends to grow
anteriorly causing upper lid swelling without dystopia, which may be visible to inspection
132
How to investigate suspected pleomorphic gland adenoma?
CT shows a round or oval mass, with a smooth outline and indentation but not destruction of the lacrimal
gland fossa. The lesion may indent the globe and calcification may be shown.
133
What is the treatment for pleomorphic gland adenoma?
Treatment involves surgical excision. If the diagnosis is strongly suspected, it is wise to avoid prior biopsy to prevent tumour.
Seeding into adjacent orbital tissue, although this may not always
be possible in the context of diagnostic uncertainty. Tumours of the palpebral lobe are usually resected, along with a margin of normal tissue, through an anterior (trans-septal) orbitotomy. Those of the orbital portion are excised through a lateral orbitotomy.
134
How is a lateral orbitotomy done for tumour excision?
1. The temporalis muscle is incised
2. The underlying bone is drilled for subsequent wiring
3. The lateral orbital wall is removed and the tumour excised including a margin of adjacent tissue and periorbita
4. The lateral orbital wall and temporalis are repaired. The prognosis is excellent provided excision is complete
135
What are the different types of lacrimal gland carcinoma in order of frequency?
adenoid cystic (50%),
pleomorphic adenocarcinoma,
mucoepidermoid,
squamous cell
136
What does histopathology of lacrimal gland carcinoma show?
Nests of basaloid cells with numerous mitoses
137
What are the symptoms of a lacrimal gland carcinoma?
* Symptoms. A malignant mixed-cell tumour presents in three main clinical settings:
○ After incomplete or piecemeal excision of a benign pleomorphic adenoma, followed by one or more recurrences over a period of several years with eventual malignant
transformation.
○As a long-standing proptosis or swollen upper lid that
suddenly starts to increase.
○Without a previous history of a pleomorphic adenoma as
a rapidly growing lacrimal gland mass, usually of several
months’ duration.
○The history is shorter than that of a benign tumour.
○Pain is a frequent feature of malignancy but may also
occur with inflammatory lesions.
138
What are the signs of a lacrimal gland carcinoma?
○ A mass in the lacrimal area causing inferonasal dystopia.
○ Posterior extension, with involvement of the superior
orbital fissure, may give rise to
epibulbar congestion, proptosis, periorbital oedema and ophthalmoplegia
○Hypoaesthesia in the region supplied by the lacrimal nerve.
○Optic disc swelling and choroidal fold
139
What are the investigations for suspected lacrimal gland carcinoma?
○ CT shows a globular lesion with irregular serrated edges, often with contiguous erosion or invasion of bone. Calcification is commonly seen within the tumour.
○Biopsy is necessary to establish the histological diagnosis. Subsequent management depends on the extent of tumour invasion of adjacent structures as seen on imaging.
○Neurological assessment is mandatory because adenoid-
cystic carcinoma exhibits perineural spread and may extend into the cavernous sinus.
140
What is the treatment for lacrimal gland carcinoma?
Treatment involves excision of the tumour and adjacent tissues.
Extensive tumours may require orbital exenteration or midfacial resection, but the prognosis for life is frequently poor. Radiotherapy combined with local resection may prolong life and reduce pain. Adjuvant intra-arterial chemotherapy and/or brachytherapy may be utilized in some cases.
141
What is an optic nerve glioma?
a slowly growing, pilocytic astrocytoma that typically affects children (median age 6.5 years)
142
What does histopathology of optic nerve glioma show?
spindle-shaped pilocytic (hair-like) astrocytes and glial filaments
143
What is the prognosis for optic nerve glioma?
The prognosis is unpredictable; some have an indolent course with little growth, while others may extend
intracranially and threaten life.
144
What conditions is optic nerve glioma associated with and is the prognosis superior when they have this condition?
Approximately 30% of patients
have associated neurofibromatosis type I (NF1) and in these patients the prognosis is superior.
145
What are the symptoms and signs of optic nerve glioma?
*Symptoms
○ Slowly progressive visual loss followed later by proptosis, although this sequence may occasionally be reversed.
○Acute loss of vision due to haemorrhage into the tumour can occur, but is uncommon.
*Signs
○ Proptosis is often non-axial, with temporal or inferior dystopia
○ The optic nerve head, initially swollen, subsequently becomes atrophic
○ Opticociliary collaterals and other fundus signs such as central retinal vein occlusion are occasionally seen.
○Intracranial spread to the chiasm and hypothalamus may develop.
146
What are the investigations for suspected optic nerve glioma?
○MRI effectively demonstrates the tumour and may show intracranial extension if present
○CT in patients with associated NF1 shows a fusiform enlargement of the optic nerve with a clear-cut margin
produced by the intact dural sheath. In patients without NF1 the nerve is more irregular and shows low-density
areas.
147
What is the treatment for optic nerve glioma?
As the tumour is intrinsic to the optic nerve, resection means that all vision will be lost in the operated eye.
*Observation may be considered in patients with a typical pilocytic astrocytoma on imaging in whom the tumour is confined to the orbit, especially if there is good vision and no significant cosmetic impairment. Serial MRI is important if this option is
chosen. Spontaneous regression has been reported, usually in NF1, but is very rare.
*Surgical excision with preservation of the globe is indicated in those with large or growing tumours where complete resection of the tumour can be achieved, particularly if vision is poor and proptosis significant. A key goal is to prevent chiasmal
involvement and an intracranial approach may be necessary to
achieve adequate resection.
*Radiotherapy may be combined with chemotherapy for tumours with extension that precludes complete surgical excision.
148
How to investigate suspected optic nerve glioma?
○ MRI effectively demonstrates the tumour and may show intracranial extension if present
○CT in patients with associated NF1 shows a fusiform enlargement of the optic nerve with a clear-cut margin
produced by the intact dural sheath. In patients without NF1 the nerve is more irregular and shows low-density
areas.
149
What is an optic nerve sheath meningioma?
a benign tumour arising
from meningothelial cells of the arachnoid villi surrounding the
intraorbital, or less commonly the intracanalicular, portion of
the optic nerve.
In some cases, the tumour merely encircles the optic nerve whilst in others it invades the nerve, growing along the fibrovascular pial septa.
150
Where within the optic nerve do most optic nerve sheath meningiomas come from?
about two-thirds of all meningiomas affecting the optic nerve arise from extension of primarily intracranial lesions.
151
What does histopathology of optic nerve sheath meningioma show?
meningothelial (irregular lobules of meningothelial cells separated
by fibrovascular strands and psammomatous (psammoma bodies among proliferating meningothelial cells types are distinguished.
152
What is the prognosis for optic nerve sheath meningioma?
The prognosis for life is good in
adults, although the tumour may be more aggressive in children, in whom 25% occur. They are more common in neurofibromatosis type II (NF2).
153
Does proptosis precede visual loss in optic nerve sheath meningioma
YES!
154
What are the symptoms and signs of optic nerve sheath meningioma?
* Symptoms typically consist of gradual visual impairment in one eye. Transient obscurations of vision may occur.
*Signs. The classic (Hoyt–Spencer) triad consists of progressive visual loss, optic atrophy and opticociliary shunt vessels, although the simultaneous occurrence of all three signs in one individual is actually uncommon.
The usual sequence of involvement is the opposite of that seen in tumours that develop outside the dural sheath:
○Optic nerve dysfunction and chronic disc swelling followed by atrophy.
○Opticociliary collaterals (30%), which regress as optic atrophy supervenes.
○Restrictive motility defects, particularly in upgaze
○Proptosis
155
What is the Hoyt Spencer Triad?
progressive visual loss, optic atrophy and opticociliary shunt vessels
156
What are the investigations for suspected optic nerve sheath meningioma?
○ CT shows thickening and calcification of the optic nerve
○MRI is the investigation of choice
○Ultrasonography (especially coronal) may be useful.
157
What is the treatment for optic nerve sheath meningioma?
Treatment may not be indicated in a middle-aged patient with a slowly growing lesion, but excision is required for an aggressive tumour, particularly if the eye is blind or there is a risk of intracranial extension.
Attempts at optic nerve-sparing surgery commonly fail but may be considered on a case basis.
Fractionated stereotactic radiotherapy may be appropriate as a vision-sparing approach, or as adjunctive treatment following surgery.
158
What is a plexiform neurofibroma?
The most common peripheral neural
tumour of the orbit.
159
What fibromatous condition is plexiform neurofibroma almost exclusively associated with?
NF-1
160
What are the symptoms/signs of plexiform neurofibroma?
Classically, involvement of the eyelids causes mechanical ptosis with a characteristic S-shaped deformity.
Diffuse involvement of the orbit with disfiguring hypertrophy of
periocular tissues may occur.
On palpation the involved tissues are
said to resemble a ‘bag of worms’. Malignant change can occur and should be suspected if there is rapid change; radiotherapy may promote this.
161
What is the treatment for plexiform neurofibroma?
Treatment is often unsatisfactory and complete surgical removal is extremely difficult. Orbital surgery should be avoided when possible because of the intricate relationship
between the tumour and important structures.
162
What % of patients with isolated neurofibroma have NF1
10%
163
What type of lymphoma is commonly found in the orbit?
The majority of orbital lymphomas are
non-Hodgkin and most of these (80%) are of B-cell origin
164
What are the symptoms and signs of orbital lymphoma?
The onset is characteristically insidious.
*Symptoms. An absence of symptoms is common, but may include discomfort, double vision, a bulging eye or a visible mass.
*Signs
○ Any part of the orbit may be affected. Anterior lesions may be palpated and generally have a rubbery consistency
○Occasionally the lymphoma may be confined to the conjunctiva or lacrimal glands, sparing the orbit.
○Local lymph nodes should be palpated, but systemic evaluation by an appropriate specialist is required.
165
What are the investigations for suspected orbital lymphoma
○ Orbital imaging, usually with MRI
○ Biopsy is usually performed to establish the diagnosis.
○ Systemic investigation to establish the extent of disease.
166
What is the treatment for orbital lymphoma?
Radiotherapy is used for localized lesions and chemotherapy for
disseminated disease and some subtypes. Immunotherapy (e.g.
rituximab) is a newer modality that may assume a dominant role
in the future. Occasionally a well-defined orbital lesion may be
resected.
167
What is the most common soft tissue sarcoma of childhood and what % occur in the head and neck?
Rhabdomyosarcoma
40% head and neck
168
What is the average age of onset for rhabdomyosarcoma?
7
169
What are the 4 subtypes of rhabdomyosarcoma?
* Embryonal constitutes the majority (85%) of orbital lesions.
Cells may show light microscopic features of striated muscle
differentiation. Embryonal usually carries a good prognosis.
* Alveolar makes up most of the balance of orbital RMS. Fewer cells show skeletal muscle differentiation than embryonal and the prognosis is worse. Particular chromosomal translocations are characteristic on cytogenetic analysis of biopsy material.
*Botyroid (4%) and pleomorphic RMS are much less common in the orbit.
170
What are the symptoms and signs of Rhabdomyosarcoma?
* Symptoms. Rapidly progressive unilateral proptosis is usual
and may mimic an inflammatory condition such as orbital cellulitis.
*Signs
○The tumour is most commonly superonasal or superior, but may arise anywhere in the orbit, including inferiorly It can also arise in other tissues, such as conjunctiva and uvea.
○Swelling and redness of overlying skin develop but the skin is not warm
○Diplopia is frequent, but pain is less common.
171
What does histopathology of rhabdomyosarcoma show?
(Masson trichrome stain); rhabdomyoblast in the centre of the field has cross striations
172
What are the investigations for suspected Rhabdomyosarcoma?
○MRI shows a poorly defined mass
○ CT shows a poorly defined mass of homogeneous density, often with adjacent bony destruction.
○Incisional biopsy is performed to confirm the diagnosis and establish the histopathological subtype and cytogenetic characteristics.
○Systemic investigation for metastasis should be performed, with lung and bone being the most common sites.
173
What is the treatment for Rhabdomyosarcoma?
Commonly used guidelines for staging and a corresponding treatment protocol were produced by the Intergroup Rhabdomyosarcoma Study Group (IRSG). Treatment encompasses a combination of radiotherapy, chemotherapy and sometimes surgical debulking. The prognosis for patients with disease confined to the orbit is good.
174
In order of frequency where are the primary tumours for orbital metastases?
the most common primary sites are breast (up to 70%), bronchus, prostate, skin (melanoma), GI tract
and kidney.
175
What are the signs of orbital metastases?
○ Dystopia and proptosis are the most common features.
○ Infiltration of orbital tissues characterized by ptosis, diplopia, brawny indurated periorbital skin and a firm orbit, with resistance to manual retropulsion of the globe.
○Enophthalmos with scirrhous tumours.
○Chronic inflammation.
○Primarily with cranial nerve involvement (II, III,IV, V, VI) and only mild proptosis with orbital apex
lesions.
176
What are the investigations for suspected orbital metastases?
○Imaging: CT and MRI typically show a non-encapsulated mass.
○Fine needle biopsy is useful for histological confirmation. If this fails, open biopsy may be required.
○A search for a primary must be carried out if the patient was not previously known to have cancer.
177
What are the treatment options for orbital metastases?
Treatment is aimed at preserving vision and relieving pain, because
most patients die within a year (average 4 months). Radiotherapy
is the mainstay of local treatment, but systemic therapy may also be of benefit. Surgical excision of the focus is occasionally carried out. Orbital exenteration is usually only performed if other modalities fail to control intolerable symptoms.
178
How does Neuroblastoma present?
one of the most common childhood malignancies. It arises from neural crest-derived tissue of the sympathetic nervous system, most commonly in the abdomen. Presentation is usually in early childhood.
Orbital metastases may be bilateral and typically present with the abrupt onset of proptosis accompanied by a
superior orbital mass and lid ecchymosis
179
What are some examples of childhood metastatic tumours?
Neuroblastoma
Langerhans cell histiocytosis
Myeloid Sarcoma
180
What is langerhans cell histiocytosis?
a rare group of disorders due to
clonal proliferations of histiocytes. Presentation ranges from localized disease, usually with bone destruction (eosinophilic granuloma), through multifocal bone involvement to a fulminant systemic disease. Soft tissues are less commonly involved, but cutaneous and visceral lesions may occur.
181
Where in the orbit do langerhans cell histiocystosis tend to occur?
Superotemporal quadrant
182
What is the most common paranasal sinus tumour which invades the orbit?
Maxillary carcinoma
183
What systemic condition is Fibrous dysplasia associated with
Polyostotic disease is associated with endocrine disorders and cutaneous pigmentation (McCune–Albright syndrome – 10% of cases).
184
How does maxillary carcinoma present?
○Otorhinolaryngological manifestations include facial pain
and swelling, epistaxis and nasal discharge.
○Ophthalmic features include upward dystopia, diplopia and epiphora
185
When is the removal of an eye or orbital content appropriate?
for intraocular or orbital malignancy or where the eye is blind and painful or unsightly.
186
What is enucleation and when is it indicated?
Removal of the globe
* Primary intraocular malignancies where other treatment modalities are not appropriate. The tumour is left intact within the eye for histopathological examination.
* After severe trauma where the risk of sympathetic ophthalmitis may outweigh any prospect of visual recovery
*Blind painful or unsightly eyes can also be managed by enucleation, although evisceration is generally considered the procedure of choice.
187
What is Evisceration?
refers to removal of the entire contents of the globe, whilst the sclera and extraocular muscles remain intact.
Generally, the cornea is removed to provide access to the ocular contents. Retention of the sclera and lack of disruption of the extraocular muscles provides better motility than is achieved after enucleation.
Evisceration provides disrupted and incomplete material for histology and should not be undertaken in the presence of suspected intraocular malignancy.
188
What is exenteration and what are its indications?
Exenteration involves removal of the globe together with the soft tissues of the orbit
*Orbital malignancy, either primary or where a tumour has invaded the orbit from the eyelids, conjunctiva, globe or
adnexa, when other forms of treatment have a very poor chance
of success.
*Non-malignant disease such as orbital mucormycosis is a rare
indication.
189
What is a cosmetic shell?
An ocular prosthesis that is used to cover a phthisical or unsightly eye. The shell can restore volume and often provides a good cosmetic appearance, with reasonable motility as a result of transmitted movements from the globe.
190
What is Post-enucleation socket syndrome (PESS)?
caused by failure to correct the volume deficit adequately. It is characterized by a deep upper lid sulcus, ptosis, enophthalmos and
backwards rotation of the top of the prosthesis.
191
What is Extrusion of an orbital implant?
significant concern with all implants.
Careful placement of an implant, ensuring it is sufficiently deep and is well covered with vascularized tissue, is more important than the choice of implant material.
192
When can initial socket moulds for ocular prosthesis be taken post enucleation/evisceration?
at around 6–8 weeks postoperatively and a temporary artificial eye placed whilst waiting for manufacture of a prosthesis shaped to fit the individual socket and matched to the fellow eye
193
What is Crouzon syndrome and what are their features?
A short anteroposterior skull
diameter, with midfacial hypoplasia giving a prominent lower jaw.
Proptosis due to shallow orbits and hypertelorism (wide orbital separation) are the most conspicuous
ocular features.
Vision-threatening complications
include exposure keratopathy and optic atrophy, mechanisms
including chronic papilloedema and cerebral hypoperfusion secondary to sleep apnoea. Strabismus (‘V’ exotropia, ametropia and amblyopia can occur and other ocular associations have been reported. Inheritance is usually autosomal dominant (AD); allelic variants in the gene FGFR2 are responsible.
194
What is Apert syndrome and what are their features?
the most severe of the craniosynostoses. Oxycephaly (conical skull), midfacial hypoplasia with a beaked nose and low-set ears syndactyly and developmental delay (30%) may be present. Shallow orbits,
proptosis and hypertelorism are generally less pronounced than in Crouzon syndrome, but the same vision-threateningcomplications occur. Inheritance can be AD, but in the majority of cases the condition is sporadic and associated with older parental age. As with Crouzon syndrome, it is frequently the
result of mutations in FGFR2.
195
What is Pfeiffer syndrome?
midfacial hypoplasia and down-
slanting palpebral fissures. Ocular features are similar to Apert syndrome. Inheritance is AD with genetic heterogeneity
196
What are the 3 conditions with craniosynostoses?
Crouzon syndrome
Pfeiffer syndrome
Apert syndrome
