11.1 The Orbit Flashcards
Thyroid eye disease
General
Epidemiology
Risk factors
Stages
Clinical signs
General
- Also known as: Thyroid associated ophthalmopathy, Grave’s ophthalmopathy
- affects 25‐50% of patients with Graves disease
- Most common cause of unilateral or bilateral proptosis in adults
- Hyperthyroid (90%), hypothyroid (5%), euthyroid (5%)
- It is an autoimmune inflammatory disorder affecting the EOM and orbital soft tissues
Epidemiology
- 30‐50 years of age
- 4:1 F:M
RF
- Smoking (dose dependent, worse TED, poor response to Rx) - Radioactive iodine (can worsen TED)
2 Stages
- Congestive (inflammatory)
➡️Eyes are red and painful
- Fibrotic (latent)
➡️White eyes
➡️Sometimes painless motility defect
Clinical signs
- Soft tissue involvement
- Lid retraction
- Proptosis
- Restrictive myopathy
- Optic neuropathy
Preseptal vs orbital cellulitis causes
Perseptal cellulitis
- trauma
- Insect bites
- Local spread e.g. stye
- sinusitis
Orbital cellulitis
- Paranasal sinusitis (eth)
- Preseptal cellulitis
- Mid face/dental infection
- Dacryocystitis
Preseptal vs Orbital cellulitis clinical features
Preseptal cellulitis
- Eyelid swelling (w or w/o erythema)
- maybe eye pain/tenderness
- chemosis (rare)
- leukocytosis (maybe)
Orbital cellulitis
- Eyelid swelling (w or w/o erythema)
- Deep eye pain / tenderness
- Pain with eye movements
- Proptosis (usually, subtle)
- Opthalmoplegia (±diplopia) {paralysis of eye}
- Vision impairment (afferent pupillary defect)
- Chemosis
- Leukocytosis
Cavernous sinus thrombosis
- Usually from facial infection, sinusitis, orbital cellulitis
- Rapid onset, +/‐ initially unilateral, usually bilateral
- Fever, rigors, malaise
IOID
- Idiopathic inflammatory disease of orbital tissues and lacrimal gland
- Old name: Orbital pseudotumour
- Enlargement of extraocular muscles and tendons
- Orbital/eye pain
- Can be recurrent
- Less systemic signs
- DDx: TED, orbital cellulitis, tumour, CST, trauma
Direct Caroticocavernous fistula (CCF)
General
Findings
- High flow fistula
- Connects ICA directly to CS
- Most common type
- Mostly caused by trauma or aneurism
- presents shortly after or within weeks of the causative trauma
- pt is frequently aware of a loud bruit in the head
Findings:
- Corkscrew scleral vessels
- Conj injection
- Chemosis
- High IOP
- Pulsatile proptosis
- Orbital bruit
Indirect caroticocavernous fistula
General
Findings
- low flow fistula
- Connects meningeal branches of CA to CS
- Associated with hypertension atherosclerosis
- May close spontaneously
Findings:
- Corkscrew scleral vessels
- Conj injection
- Chemosis
- High IOP
Orbital trauma: Retrobulbar Hx
Signs and symptoms
- Eyelid swelling/haematoma
- Subconjunctival hx
- Limitation of eye movements
- Decreased sensation: cheek and tip of nose
Hx - Haemorrhage
Orbital trauma: Blow-out fracture
General
Signs and symptoms
- involve the orbital walls, but leave the orbital margin intact.
- The floor and medial wall are most frequently involved.
- The fracture is caused by an anteroposterior compression injury from a fist, a tennis ball or a similarly sized object which has a significantly larger diameter than the orbital margin.
Signs and symptoms
- Diplopia
- Enophthalmos
- Periorbital crepitus
- Decreased sensation: cheek and tip of nose
Paediatric orbital conditions: Rhabdomyosarcoma
- commonest primary malignant orbital tumour in children
- 3‐4% of all childhood cancer
- Males>females, mostly Caucasians
- 66% under 10 years, average age 7
- From undifferentiated, pluripotent cell of soft tissue, not
from EOM - Highly malignant: aggressive local spread through bones.
- Mets to chest
- Rapid proptosis over weeks
- unilateral
- Down and out displacement: location most common supero‐temporal orbit
- Red eyelid discolouration
Paediatric orbital conditions: trap‐door blow‐out fracture
- Greenstick orbital fracture
- Fat and muscle may entrap
- Urgent referral: surgery needed in 48‐72hours to prevent necrosis
- Surgery if:
◦ Oculocardiac reflex persists
◦ Early enophthalmos with facial asymmetry
◦ White‐eye appearance with entrapment
Orbital tumours: Vascular tumours
CAPILLARY HAEMANGIOMA
- Usually presents at or shortly after birth
- May enlarge with crying and may spontaneously disappear by the age of 5 years
CAVERNOUS HAEMANGIOMA
- commonest benign orbital tumour in adults
LYMPHANGIOMA
- Often occurs in children and may suddenly enlarge due to haemorrhage in the lesion
Orbital tumours: Neural tumours
OPTIC NERVE GLIOMA
- Fusiform intradural lesion
- Slow growing, usually benign
- Associated with NF‐1
- Non‐axial proptosis
- Optociliary shunt vessels
OPTIC NERVE SHEATH MENINGIOMA
- Rare and benign
- Adult women
- “tram‐track” or “donut” sign on MRI
Orbital tumours: Lacrimal gland tumour
Pleomorphic adenoma
- 4‐5th decade
- Men>women
- Benign, can have malignant change
- Slow growth and painless
Pleomorphic adenocarcinoma
- Elderly
- Rapid, progressive, painful proptosis
Orbital tumours: Metastatic tumours
- not common
Primary sites:
- breast
- bronchus
- prostate
