1
Q
What bones make up the roof of the orbit
A
lesser wing of the sphenoid
and the orbital plate of the frontal bone.
2
Q
What bones make up the lateral orbital wall
A
the greater wing of
the sphenoid and the zygomatic
3
Q
What bones make up the floor of the orbit
A
three bones: the zygomatic, maxillary and
palatine.
4
Q
What bones make up the medial orbital wall
A
four bones: maxillary, lacrimal, ethmoid and sphenoid
5
Q
What structures pass through superior orbital fissure
A
Superior portion: lacrimal, frontal and
trochlear nerves and the superior ophthalmic vein.
Inferior portion: superior and inferior
divisions of the oculomotor nerve, the abducens and nasociliary nerves and sympathetic fibres from the cavernous plexus.
6
Q
What is Tolosa Hunt syndrome
A
Inflammation of the superior orbital fissure and apex
may therefore result in a multitude of signs including ophthalmoplegia and venous outflow obstruction.
7
Q
What runs through the inferior orbital fissure
A
maxillary nerve, the zygomatic nerve and branches of the pterygopalatine ganglion, as well as the inferior ophthalmic vein.
8
Q
Clinical features of orbital disease in general
A
Symptoms: eyelid/conjunctival swelling/redness/watering/pain/sunken eye impression/double vision/blurring/pulsation/bruit in orbit
Soft tissue involvement: eyelid/periocular oedema/ptosis/skin discolouration/ epibulbar injection. Caused by TED, orbital inflammatory disease, obstruction to venous drainage
Proptosis
9
Q
Which conditions cause axial proptosis?
A
space-occupying lesions within the muscle cone
such as a cavernous haemangioma or optic nerve tumours cause axial proptosis,
10
Q
Where can the pathology be in the orbit to cause dystopia and proptosis
A
extraconal lesions
11
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
12
Q
How are the Hertel and Luedde Exophthalmometer used
A
Rule resting on the lateral orbital margin. Using visualization of the corneal apices to determine the degree of ocular protrusion from a scale.
Readings >20mm abnormal
Difference greater than 2-3 mm between the eyes are suspiscious
13
Q
What is enophthalmos and list some causes
A
implies recession of the globe within the orbit.
Causes: congenital and traumatic orbital wall abnormalities, atrophy of the orbital contents (e.g. radiotherapy, scleroderma, chronic eye poking in blind infants – the ‘oculodigital’ sign or sclerosis
14
Q
How does the forced duction test differentiate restrictive from neurological motility defect
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 indicates restrictive. No resistance noted in neurological
15
Q
What is the differential IOP test
A
IOP is measured in the primary posi-
tion 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).
16
Q
What do saccadic eye movements look like in neurological vs restrictive pathology
A
in neurological lesions are reduced
in velocity, while restrictive defects manifest normal saccadic velocity with sudden halting of ocular movement.
17
Q
What are the causes of orbital pulsation
A
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
18
Q
What are optociliary 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.
19
Q
What conditions are associated with optociliary shunt vessels
A
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.
20
Q
What is MRI useful for in orbital scans
A
Demonstrate orbital apex lesions and intracranial extension of orbital tumours and is useful for imaging orbital inflammatory disease
21
Q
What sequencing in MRI scans is good for TED
A
STIR
22
Q
Pathogenesis of thyrotoxicosis
A
an autoimmune disorder in which IgG antibodies bind to receptors in the thyroid gland and stimulate secretion of thyroid hormones.
23
Q
Treatment options for Thyrotoxicosis
A
carbimazole, propylthiouracil, propranolol, thyroid ablation with radioactive iodine and partial
thyroidectomy.
24
Q
What are the risk factors for TED
A
Once a patient has Graves disease, the major clinical risk factor for developing TED is smoking. Women are five times more likely to be affected by TED than men, but this largely reflects the increased incidence of Graves disease in women.
Radioactive iodine used to treat hyperthyroidism can worsen TED.
25
What is the pathogenesis for thyroid ophthalmopathy
organ-specific autoimmune reaction in which anti-thyrotropin-receptor antibody reacts
against thyroid gland cells and orbital fibroblasts. Insulin-like growth factor 1 receptor (IGF-1R) and the thyroid-stimulating hormone receptor (TSHR) are upregulated in orbital and brow fat. This leads to inflammation of extraocular muscles, interstitial
tissues, orbital fat and lacrimal glands. Pleomorphic cellular infiltration and increased GAG secretions leads to osmotic water inhibition. Orbital volume content increases, muscles swell upto 8x normal size.
26
How does restrictive myopathy and diplopia come about in TED
Subsequent degeneration of muscle fibres eventually leads to fibrosis, which exerts a tethering effect on the involved muscle, resulting in restrictive myopathy and diplopia.
27
What is the progression of TED
a congestive (inflammatory) stage in which the eyes are red and painful. is tends to remit within
1–3 years and only about 10% of patients develop serious long- term ocular problems. A fibrotic (quiescent) stage follows in which the eyes are white, although a painless motility defect may be present.
28
Clinical features of TED
(1) soft tissue involvement, (2) lid retraction, (3) proptosis, (4) optic neuropathy and (5) restrictive myopathy.
29
What is the EUGOGO Activity features of TED
Spontaneous retrobulbar pain.
Pain on attempted upward or downward gaze.
Redness of eyelids.
Redness of conjunctiva.
Swelling of conjunctiva or plica.
Swelling of eyelids.
Chemosis.
30
What is the EUGOGO severity classification of TED
Mild, with only a minor impact on daily life.
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
Sight-threatening due to optic neuropathy or corneal
breakdown.
31
How does lid retraction occur in TED
50% of patients with Graves
Overaction of Müller muscle is postulated
to occur as a result of sympathetic overstimulation secondary to high levels of thyroid hormones. Fibrotic contracture of the levator palpebrae and inferior rectus muscles associated with adhesion to
overlying orbital tissues is another probable mechanism, together with secondary overaction in response to hypo- or hypertropia
produced by fibrosis.
32
When is lid retraction suspected in TED
when upper lid margin sits at the limbus or above resulting in scleral show
33
What is the Dalrymple sign
lid retraction or lid spasm in primary gaze leading to a widened palpebral opening
34
What is the Kocher sign
A staring and frightened appearance of the eyes, which is particularly marked on attentive
fixation
35
What is the von Graefe sign
signifies retarded descent of the upper
lid on downgaze
36
What percentage of patients with TED develop ophthalmoplegia
Between 30% and 50% of patients
37
What is the order of restrictive myopathy 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.
38
How does optic neuropathy occur in TED
serious complication caused by compression of the optic nerve or its blood supply at the orbital apex by the congested and enlarged recti and swollen orbital tissue. This may occur in the ABSENCE of Proptosis
39
What does imaging scan show in TED
typical pattern of extraocular muscle involvement in TED, consisting of muscle belly enlargement with tendon sparing. Imaging is also used in the assessment of optic nerve compression and prior
to orbital wall surgery.
40
How is TED treated?
depends on (a) clinical activity, (b)
severity and (c) duration of the orbitopathy.
Ant-inflammatory/immunosuppressive treatment less effective after 18 months of disease duration
Smoking cessation
Radio-iodine treatment
41
How is mild TED managed?
Lubricants for SLK, corneal exposure, dryness
Topical steroid/NSAID/Ciclospirin
Selenium daily for 6 months
Head elevation with 3 pillows reduce periorbital oedema
Eyelid taping during sleep alleviate exposure keratopathy
42
How is moderate- severe TED managed?
Use EUGOGO classification- treat if score 3 or more
Systemic steroids Prednisolone 60-80mg OD
IV methylprednisolone reserved for optic neuropathy but outcomes superior compared to oral prednisolone
IV Methylprednisolone + MMF superior compared to steroid alone
Orbital steroid injections in select cases
Low dose fractionated radiotherapy used as second line therapy. Used when steroids contraindicated/ineffective
Combined therapy with irradiation/azathioprine/low dose prednisolone more effective than just steroid/radiotherapy alone
Optic neuropathy - Pulsed IV methylprednisolone 0.5-1g OD for 3 days with oral conversion to 40mg OD Prednisolone/ 0.5mg alternated days IV, keep maximum dose to <8grams. Orbital wall decompression may be needed if steroids ineffective
43
what is a good low intensity regime for moderate-severe TED
IV methylprednisolone 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
44
Side effects of radiation therapy for TED
Cataract, radiation retinopathy, optic neuropathy and an increased risk of local cancer. The threshold for its use should be higher in younger patients and diabetics, the latter because of a possibly
increased risk of retinopathy.
45
What are some second line treatments for Moderate to severe TED
persistent, corticosteroid- resistant disease or non-response to first-line treatment includes the use of monoclonal antibody treatment with rituximab, tocilizumab or teprotumumab. Teprotumumab side effect is hearing loss
46
When is eyelid surgery done in TED
only aer any necessary orbital and then strabis-
mus procedures have been undertaken, as orbital decompression may impact both ocular motility and eyelid position, and extraocular muscle surgery may affect eyelid position
47
How can proptosis in TED be managed
Surgical decompression increases the volume of the orbit by removing the bony walls and may be combined with removal of orbital fat.
One-wall (deep lateral) decompression (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 signifcant 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.
48
How can restrictive myopathy be managed in TED
Surgery is required in most cases expe-
riencing persistent diplopia in the primary or reading positions of gaze, provided the inflammatory stage has subsided and the angle of deviation has been stable for at least 6–12 months. Until then, botox and prisms are used
49
What is the most common indicated surgery for 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
50
What are the 5 Chandler–Hubert classification of
orbital complications of sinus infection
Type I: preseptal cellulitis
Type II: post-septal cellulitis
Type III: subperiosteal abscess
Type IV: orbital abscess
Type V: cavernous sinus thrombosis
51
What organisms are responsible for preseptal cellulitis
S. aureus
S. pyogenes
52
What organisms are responsible for orbital cellulitis
Streptococcus pneumoniae, Staphylococcus aureus, Streptococcus pyogenes and
Haemophilus influenzae
53
Ddx of an acutely inflamed orbit
Infection: Bacterial/fungal orbital infection/dacryocystitis/infective dacryocystitis
Vascular:
acute orbital haemorrhage/cavernous sinus thrombosis/carotid cavernous fistula
Neoplasia:
Rapidly progressive retinoblastoma/lacrimal gland tumour/rhabdo/leukaemia
Endocrine:
TED of rapid onset
Non neoplsatic
Idiopathic orbital inflammatory disease
Tolosa, Tolosa Hunt, Orbital myositis, HZO, HSV skin rash, Sarcoid, Scleritis, ruptured dermoid cyst
54
Complications of orbital cellulitis
optic neuropathy, exposure
keratopathy, raised IOP, endophthalmitis and occlusion of
the central retinal artery or vein.
Subperiosteal abscess, most frequently located along the
medial orbital wall.
Intracranial complications, which are uncommon (3–4%) but extremely serious, include meningitis, brain abscess and cavernous sinus thrombosis.
55
How to investigate orbital cellulitis
Ascertain tetanus status in trauma case
White cell count
Blood cultures
Nasal discharge culture
HR-CT of orbit/sinus/brain
LP if meningeal/cerebral signs
56
How to manage orbital cellulitis
Admit with ENT review
Delineate erythema
Antibiotics IV: Cef/Metro continue until apyrexial for 4 days then step down
Monitor ON function every 4 hours min
Surgery: drain orbital abscess early + biopsy. Optic nerve compression may need canthotomy/cantholysis
57
What is Mucormycosis and who does it affect typically
rare aggressive and often fatal infection caused by fungi of the family Mucoraceae. Affects patients with DKA/immunosuppressed
58
How is mucurmycosis acquired
inhalation of spores with URTI. Spread to sinuses and orbit/brain invasion. Invasion of blood vessels leads by hyphae leads to occlusive vasculitis + infarction of orbital tissues
59
How to treat rhinoorbital mucormycosis
Admit
IV antifungal
Correct underlying metabolic defect
Daily packing and irrigation of areas with antifungal agent
wide excision of devitalized/necrotic tissue
hyperbaric oxygen
60
What is orbital pseudotumour
uncommon disorder characterized by non-neoplastic, non-infective,
space-occupying orbital infiltration with inflammatory features.
Usually unilateral in adults, bilateral in children
61
What does histology of orbital pseudotumour show (IOID)
pleomorphic inflamma-
tory cellular infiltration followed by reactive fibrosis
62
Signs/symptoms of IOID
Symptoms: acute/subacute ocular/periocular redness/swelling/pain.
Signs: Pyrexia/congestive proptosis/mild/severe ophthalmoplegia. Features of ON dysfunction. Choroidal folds
63
What is the natural history of IOID
Variable: spontaneous resolution within weeks without sequelae. Intermittent episodes of activity with eventual remission. Prolonged inflammation with fibrosis of orbital tissues resulting in frozen orbit + ptosis/ON compression
64
How to investigate IOID
CT shows ill defined orbital opacification and loss of definition of contents
Biopsy for persistent cases to confirm diagnosis/rule out neoplasia/systemic inflammatory conditions
Rule out lymphoma/non neoplastic infiltrative disorders like sarcoid/GPA
65
How to treat IOID
Observe
NSAIDS alone + PPI
PO Steroids once diagnosis confirmed. PO pred 1mg/kg taper over weeks
Orbital depot steroid
Radiotherapy if no response with PO steroid
66
What is orbital myositis
idiopathic non specific inflammation of one or more EOM. Subtype of IOID
67
What does histology of orbital myositis show
chronic inflammatory cellular infiltrate with the muscle fibres
68
Signs and symptoms of orbital myositis
Symptoms: pain exacerbated by eye movement. Onset in early adulthood.
Signs less obvious than IOID. Lid oedema/ptosis/chemosis/pain diplopia with eye movements/injected muscle/some cases fibrosis of muscle with permanent restrictive myopathy
69
What is the natural 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.
70
What does neuroimaging of orbital myositis show
primarily 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.
71
Treatment for orbital myositis?
NSAIDs may be ade-
quate 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.
72
Causes of acute dacryoadenitis?
idiopathic or due to viral (e.g. mumps,
Epstein–Barr, cytomegalovirus) or – rarely – bacterial infection; the lacrimal gland is often involved in IOID
Chronic conditions
such as sarcoidosis, Sjögren syndrome, thyroid disease and some chronic infections usually give a less acute onset and involvement
can be bilateral.
73
CT of dacryoadenitis vs tumour?
CT shows enlargement of the
gland and involvement of adjacent tissues without bony
erosion; the latter suggests a tumour.
74
What is Tolosa Hunt Syndrome
rare idiopathic condition caused by nonspecific granulomatous inflammation of the cavernous sinus, superior orbital fissure and/or orbital apex. It is a diagnosis of exclusion and
should be investigated fully
75
How to treat Tolosa Hunt syndrome
systemic steroids and other immunosuppressants as necessary
76
What is GPA and what serological test is useful
idiopathic multisystem granulomatous disorder that may involve the orbit, often bilaterally, usually by contiguous spread from the paranasal sinuses or nasopharynx.
cANCA
77
How to treat GPA
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
78
What is a carotid cavernous fistula
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.
79
What is a direct Carotid cavernous fistula
high-fow 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.
80
What is an indirect carotid cavernous fistula (dural shunt)?
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. Spontaneous rupture
of an atherosclerotic artery or of a congenital malformation is the usual cause and may be precipitated by minor trauma or straining.
81
Symptoms of direct and indirect CCF
direct. 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.
Indirect. Gradual onset of redness of one or both eyes is a typical presentation, caused by conjunctival vascular
engorgement.
82
What investigative tests are done for CCF
CT/MRI- prominence of superior ophthalmic vein and diffuse enlargement of EOM. Orbital doppler may show abnormal flow patterns. Definitive diagnosis: selective catheter digital subtraction angiography. CTA/MRA can be useful
83
How to treat direct and indirect CCF
Direct: most CCF are NOT life threatening- eye is at risk. Surgery indicated if no spontaneous closure. Post trauma unlikely to self close due to higher blood flow. Transarterial approach to repair and coil the artery or occlude the involved sinus. Sometimes craniotomy.
Indirect: if needed, treatment is transvenous closure of involved sinus. Spontaneous closure in upto 50%. Intermittent carotid compression increases likelihood of closure
84
What is an orbital dermoid cyst
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.
85
What is the histology of a dermoid?
lined by keratinized stratified squamous
epithelium (like skin), have a fibrous wall and contain dermal appendages such as sweat glands, sebaceous glands and hair follicles; epidermoid cysts do not contain adnexal structures.
86
Signs of dermoid cyst
Superotemporal location orbit. Firm round smooth non tender mass 1-2cm diameter mobiel under skin but tethered to periosteum. Deeper dermoids cause dystopia/mass lesion with indistinct margins
87
How to investigate and treat orbital dermoids
Ix: imaging for all cases. r/o dumb bell/sub periosteal extension
superficial: imaging shows well circumscribed heterogenous cystic lesion
deep: well circumscribed lesion. Some deep dermoids with bony defect extend into inferotemporal fossa/intracranially
treat superficial by excision in toto without rupturing lesion as it can cause severe granulomatous inflammation
deep: excision in toto. similar reason
88
What is a sinus mucocoele
develops when drainage of paranasal sinus secretions blocked (infection/allergy/trauma/congenital narrowing). Expanding cystic debris erodes bony walls of sinus causing enroachment on orbital tissues. Usually from frontal or ethmoid mucocoele. Rarely maxillary sinus.
89
What are primary orbital varices
plexus of thin-
walled distensible low-flow vein-like vessels that are commonly,
though not always, intrinsic to the normal circulation. Associations include varices of the eyelids and conjunctiva
90
What is a hamartoma
a disorganized over-
growth of mature tissues normally present in the involved area
91
What are some features of orbital varices
unilateral and nasal
non pulsatile proptosis without bruit. Can be precipitated by valsalva manoeuvre, head down position/ external compression of jugular veins.
92
What are MRI/CT/US/Venography features of orbital varices
lobulated mass with variable contrast enhancement and phleboliths + orbital expansion.
93
How to treat orbital varices
surgical excision difficult and incomplete. most dont need treatment. Bleed easily. Complicated by severe orbital haemorrhage + vascular optic nerve compromise.
94
What is a lymphangioma
rare hamartomatous vascular tumour that
tends to enlarge and infiltrate dffusely 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.
95
What is a classic feature of lymphangiomas
chocolate cysts due to bleeding into the lumen which regresses spontaneously with time
96
What is a capillary haemangioma?
most common tumour of the orbit and periorbital area in childhood. An
established tumour is composed of anastomosing small vascular channels without true encapsulation. It is a hamartoma and believed to be due principally to endothelial
cell proliferation.
97
What is Kasabach Merritt syndrome
Large/ multiple Capillary haemangiomas with visceral involvement and thrombocytopaenia and high output cardiac failure
98
What are the signs of Capillary Haemangioma
strawberry naevus bright red, preseptal deeper tumours dark blue/purple through skin located superiorly. Large tumour becomes blue when crying. Pulsation bruit absent. Deep tumours--> proptosis without skin discolouration.
99
How to investigate capillary haemangioma
Imaging for other than very small lesions to rule out more extensive orbital extension. USS shows medium internal reflectivity and on MRI/CT soft tissue mass in anterior orbit/extraconal mass with finger like posterior expansions. Orbital cavity may show enlargement but no bony erosion
100
What is the natural course of a capillary haemangioma?
rapid growth and 3-6 months after diagnosis. Followed by slow phase of natural resolution in which 30% resolve by age 3 and 75% by age 7. Treatment for secondary amblyopia/ astigmatism/ anisometropia/ occlusion/ strabismus.
101
How is capillary haemangioma treated
beta blockers- oral propranolol. topical timolol equally effective. no side effects.
steroids: injection of kenalog into a cutaneous/ preseptal tumour effective. Regression in 2 weeks. Deep orbital injection may cause CRAO.
Laser can be used to close blood vessels in superficial skin lesions <2mm thick. Inferferon alfa 2a and vincrinstine for steroid resistant sight threatening lesions. Local resection with cutting cautery/CO2 laser reduce bulk of anterior tumour. Reserved for late inactive stage.
102
What is a cavernous haemangioma and where is it found in the orbit?
most common orbital tumour in adults and is
probably a vascular malformation rather than a neoplastic lesion.
lateral part of the muscle cone just behind the globe behaves like a low flow arteriovenous malformation
103
What does histology of cavernous haemangioma show?
endothelial-lined vascular channels of varying size separated by fibrous septa
104
Signs and symptoms of cavernous haemangioma
symptoms: slow progressive unilateral proptosis.
Signs: axial proptosis, associated with optic disc oedema and choroidal folds. Lesion at orbital apex may compress ON without proptosis. Impairment of EOM excursion
105
How to investigate cavernous haemangioma
CT/MRI show well circumscribed oval lesion within muscle cone. Slow contrast enhancement. USS also helpful.
106
How to treat Cavernous haemangioma
many are detected incidentally. Observation alone appropriate. Symptomatic lesions need excision as they enlarge. Usually well encapsulated unlike capillary counterpart and easier to remove
107
What is a pleomorphic lacrimal gland adenoma
the most common epithelial tumour of the lacrimal gland and is derived from the ducts and secretory elements including myoepithelial cells.
108
What does histology show on pleomorphic lacrimal gland adenoma
inner layer of cells forms glandular tissue that may be associated with squamous differentiation and
keratin production.
Outer cells undergo metaplastic change leading to the formation of myxoid tissue.
109
Symptoms/signs of lacrimal pleomorphic adenoma
symptoms: painless slow progressive ptosis/swelling in superotemporal eyelid >1 year
orbital lobe tumour smooth firm non tender mass in lacrimal gland fossa with inferonasal dystopia.
palpebral lobe tumour less common grows anteriorly causing upper lid swelling without dystopia
110
CT findings in lacrimal pleomorphic adenoma
round/oval mass with smooth outline and indentation but no destruction of lacrimal gland fossa. The lesion may indent the globe and calcification may be shown
111
How to treat pleomorphic lacrimal gland adenoma
surgical excision- wise to avoid biopsy to prevent tumour seeding. Tumours of palpebral origin resected with normal tissue through anterior trans septal orbitotomy
112
What are the common histological types of lacrimal gland carcinoma in order of frequency
adenoid cystic (50%), pleomorphic adenocarcinoma, mucoepidermoid and squamous cell
113
What are the histological features of lacrimal gland carcinoma
nests of basaloid cells with numerous mitoses
114
Can an incomplete excision of a benign pleomorphic adenoma lead to malignant transformation
yes!! BEWARE OF IT
115
What investigations are done for lacrimal gland carcinoma and what do they show
CT- globular lesion irregular serrated edges with contiguous erosion/bone invasion. Calcification seen within the tumour
Biopsy- helps make diagnosis. Neurological assessment mandatory as adenoid cystic carcinoma shows perineural spread into cavernous sinus
116
What is the treatment for lacrimal gland carcinoma
excision of tumour and adjacent tissues. Extensive tumours may require orbital exenteration/midfacial resection. Poor prognosis. Radiotherapy + local resection may prolong life and reduce pain. Adjuvant intra arterial chemo/brachytherapy may be useful
117
What is an optic nerve glioma
slowly growing, pilocytic astrocytoma that typically affects children (median age 6.5 years).
118
What are the histological findings of an optic nerve glioma
spindle-shaped pilocytic (hair-like) astrocytes and glial filaments
119
What is the commonest association of optic nerve glioma
NF1- superior prognosis (30%) of optic nerve glioma patients will have NF1
120
Signs/symptoms of optic nerve glioma
slow progressive visual loss + proptosis later. acute loss of vision due to haemorrhage into tumour
proptosis- non axial with temporal/inferior dystopia. ONH swollen then atrophy. Opticociliary collaterals and RVO seen, intracranial spread to chiasm/hypothalamus may be seen
121
What are the MRI and CT findings in optic nerve glioma
MRI- shows tumour well and intracranial extension
CT- in patients with NF1 associated shows fusiform enlargement of ON with clear cut margin by intact dural sheath. In patients without NF1, nerve more irregular and low density areas
122
How to treat optic nerve glioma
As tumour intrinsic to nerve- vision will be lost if nerve resected.
Observation in patients with pilocytic astrocytoma and confined to orbit especially if good vision and no significant cosmetic impairment. Spontaneous regression reported but rare.
Surgical excision with globe preservation in large tumours if vision poor/proptosis significant. Goal is to prevent chiasmal involvement and intracranial approach may be needed for complete resection. Radiotherapy + chemotherapy for tumours with extension precluding complete excision
123
What is 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.
two-thirds
of all meningiomas affecting the optic nerve arise from extension of primarily intracranial lesions.
124
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)
125
What is the association of Optic nerve sheath meningioma
NF-2
126
What comes first in Optic nerve sheath meningioma. Vision loss or proptosis
vision loss
127
What are the symptoms and signs of optic nerve sheath meningioma
gradual visual impairment
Hoyt Spencer Triad
progressive visual loss
optic atrophy
opticociliary shunt vessels
ON dysfunction + chronic disc swelling followed by atrophy
opticociliary collaterals 30% regressing as optic atrophy supervenes, restrictive motility defects in upgaze, proptosis.
128
What investigations are done in optic nerve sheath meningioma and what do they show
CT- thickening and calcification of ON
MRI choice investigation
US especially coronal useful
129
How is optic nerve sheath meningioma treated
may not be indicated in middle aged patient with slow growing lesion but excision needed for aggressive tumour if eye blind/risk of intracranial extension. ON sparing surgery fails. Fractionated stereotactic radiotherapy may be appropriate or adjunctive following surgery
130
What is the most common peripheral neural orbital tumour
Plexiform neurofibroma. Almost exclusively associated with NF1
131
How does plexiform neurofibroma present
Mechanical ptosis with S shaped deformity. Tissues resemble a 'bag of worms' on palpation.
132
What is the commonest orbital lymphoma
Non Hodgkin - most (80%) are B cell origin. Affects older individuals.
133
What are the symptoms and signs of orbital lymphoma
discomfort, diplopia,proptosis, visible mass
signs- anterior lesions may be palpated and have rubbery consistency. lymphoma may be confined to conjunctiva/ lacrimal gland/spare orbits
local lymph nodes palpated but systemic evaluation required
134
What investigations are done for suspected orbital lymphoma
Orbital imaging with MRI
Biopsy
Systemic Ix to establish extent
135
What is the treatment for orbital lymphoma
Radiotherapy for localised lesions/ chemotherapy for disseminated disease.
Immunotherapy with rituximab and a well defined orbital lesion may be resected
136
What is the most common soft tissue tumour of childhood
Rhabdomyosarcoma
40% develop in head and neck
137
What is the commonest primary orbital malignancy in children and what is the average age of diagnosis
Rhabdomyosarcoma
Average age 7 years
138
What gene is responsible for Rhabdomyosarcoma
Various including variants of RB1 (retinoblastoma gene)
139
What are the 4 subtypes of rhabdomyosarcoma
Embryonal (85%)- Good prognosis
Alveolar
Botryoid (4%)
Pleomorphic
140
What are the signs and symptoms of rhabdomyosarcoma
rapidly progressive unilateral proptosis- mimics orbital cellulitis
tumour superonasal/superior but even inferiorly. Can arise in conj/uvea. Diplopia frequent pain less common.
141
What do the Ix show in Rhabdomyosarcoma
MRI- poorly defined mass
CT poorly defined mass of homogenous density with adjacent bony destruction
Incisional biopsy to confirm diagnosis and histology subtype
142
What are the commonest site for RMS metastases
Lung
Bone
143
How to treat RMS
IRSG defined guidelines for RMS treatment.
Combination chemo/ radiotherapy. Sometimes surgical debulking. A single oncogenic fusion gene associated with treatment resistance and 40-45% decreased survival rate.Entinostat with chemo can improve prognosis. If confined to orbit good prognosis
144
What are the commonest primary tumours with orbital metastases
Breast (upto 70%)
Bronchus
Prostate
Skin (melanoma)
GI tract
Kidney
145
What do the investigation findings show in orbital metastatic tumours
CT/MRI show encapsulated mass
Fine needle biopsy useful
Search for primary tumour important if not known to have cancer
146
What is the treatment for orbital metastatic tumours
Aim is preserve vision/ reduce pain. Most patients die within 12 months (average 4 months). Radiotherapy is mainstay of treatment. systemic therapy may be of benefit. Surgical excision is often carried out. Orbital exenteration only done if all else fails
147
Where does neuroblastoma arise from?
neural crest derived tissue of sympathetic nervous system. Most common in abdomen
148
What is the most common sinus tumour to invade the orbit
Maxillary carcinoma
149
What are polyostotic disease in sinus tumours associated with (syndrome)
Mc Cune Albright
150
What is silent sinus syndrome
Rare- middle aged people affected. Spontaneous collapse of maxillary sinus and orbital floor secondary to negative pressure in sinus. CT confirms diagnosis.
151
Signs of silent sinus syndrome
facial assymetry
enophthalmos
diplopia due to IO entrapment
MRI shows maxillary sinus outlet obstruction, sinus opacification, sinus volume loss
152
How is silent sinus syndrome treated
early surgery better outcomes
surgical treatment is restoring sinus function by improving sinus drainage. Orbital floor reconstruction can be done at the same time.
153
What is enucleation and what are the indications
removal of the globe
1) Primary intraocular malignancies
2) After severe trauma where risk of SO outweighs any prospect of vision recovery
3) Blind painful or unsightly eyes
154
What is evisceration
removal of entire globe contents whilst sclera/EOM intact. Cornea removed to provide access to ocular contents. Should NOT be done in cases of intraocular malignancy
155
What is exenteration
removal of globe + soft tissues of the orbit
1) Orbital malignancy
2) Non malignant disease like orbital mucormycosis rare indication
156
What is a cosmetic shell
ocular prosthesis used to cover phthisical or unsightly eye. Shell can restore volume and provide good cosmetic appearance with some transmitted movements from the globe
157
When are orbital implants used
Orbital volume reduction happens after enucleation/ evisceration. Large prosthetic eye without underlying orbital implant does not provide satisfactory solution due to stretching of lower lid due to weight and poor mobility. Implant inserted when eye removed. Can be solid/porous Fibrovascular ingrowth into porpus facilitates motility of an overlying prosthesis
158
What is PESS
a combination of signs that occur as a consequence of a volume deficit of the orbital tissues. Common if implant not used. Upper lid loses support after enucleation and drops down over prosthesis
159
What are the features of PESS
Enophthalmos
Upper lid ptosis
Superior sulcus hollowing
Sagging lower lid
160
What are the surgical options to treat PESS
1) Insert secondary implant if absent
2) insert silicone block into inferior orbit if implant present
3) implant dermis fat graft
161
What is a conformer
After enucleation/ evisceration conformer made of silicone/ acrylic material placed to support conj fornices remains in place till socket fitted with artificial eye.
162
When can socket moulds be made after enucleation/evisceration
6-8 weeks post op
163
What are the 3 commonest craniosynostoses conditions
Crouzon syndrome
Apert syndrome
Pfeiffer syndrome
164
Features of crouzon syndrome
short AP skull diameter
midfacial hypoplasia
proptosis due to shallow orbits
hypertelorism
V exotropia
exposure keratopathy
optic atrophy
amblyopia
Inheritance AD gene FGFR 2
165
Features of Apert syndrome
most severe of craniosynostoses
oxycephaly
midfacial hypoplasia
beaked nose, low set ears
syndactly and developmental delay
shallow orbits/ proptosis/ hypertelorism less pronounced.
Inheritance AD. Mutation in FGFR2
166
Features of Pfeiffer syndrome
midfacial hypoplasia
down slanting palpebral fissures
similar ocular features to other craniosynostoses. Inheritance AD + genetic heterogeneity
167
Part 2
flashcards
Decks in class (20)
# Cards
-
Exam Techniques68
-
Eyelids183
-
Lacrimal Drainage System41
-
Orbit167
-
Dry Eye34
-
Conjunctiva80
-
Cornea183
-
Corneal and Refractive Surgery49
-
Episclera and Sclera35
-
Lens101
-
Glaucoma236
-
Uveitis191
-
Retinal Vascular Disease147
-
Acquired Macula Disorders163
-
Inherited Retinal Degenerations127
-
Retinal Detachment99
-
Vitreous Opacities10
-
Strabismus201
-
Neuro-ophthalmology352
-
Ocular Tumours164
