Orbital disease Flashcards
1
Q
anatomy
A
- The orbit protects, supports and maximises the function of the eye
- The orbit contains the eye, EOMs, muscles, nerves vasculature & connective tissue
- Most complex anatomy of the human body
The orbit is a pear-shaped cavity, the stalk of which is the optic canal. - The roof consists of two bones: lesser wing of sphenoid bone & orbital plate of the frontal bone
- Lateral wall: zygomatic bone & greater wing of sphenoid bone
- Medial wall: maxillary bone, lacrimal bone, ethmoid bone, body of sphenoid bone
- Floor: maxillary bone, zygomatic bone, palatine bone.
2
Q
Thyroid eye disease
A
- Most common orbital lesion – 50%
- The thyroid regulates metabolism by realising thyroxin
- Immunological disorder that affects the orbital muscles and fat
- Middle-ages adults (30-50 years) are affected most frequently – almost unheard of in children and older people
- F > M, 3-4:1
- It is a bilateral process (since it is systemic), but often asymmetrical
o Can appear unilateral because it can be asymmetrical - Multiple muscles are involved simultaneously, most commonly the inferior and medial rectus.
- TED typically proceeds through an inflammatory stage in which the eyes are red & painful; tends to remit within 1-3 years, only 10% px’s = serious long-term ocular problems.
- A fibrotic (quiescent) stage follows in which eyes are white, although a painless motility defect may be present
3
Q
Thyroid eye disease symptoms
A
- Grittiness
- Red eyes
- Lacrimation
- Photophobia
- Ruffy lids
- Retrobulbar (behind the eyes) discomfort
- Cosmetics – staring/bulging appearance
4
Q
Thyroid eye disease signs
A
- Dry eyes – most common, inflammation which affects the muscles/fat also affects goblet cells in the conjunctiva which affect the tear film and make px more prone to dry eye
- Conjunctival injection -epibulbar hyperaemia
- Lid retraction
o 50% of patients with TED.
o Overaction of mullers muscle – sympathetic overstimulation due to high levels of thyroid hormones.
o Fibrotic contractor of levator & IR - Exophthalmos
- Diplopia
- Corneal exposure – punctate epithelial erosion, superior limbic keratoconjunctivitis, exposure keratopathy
- Optic nerve compression (optic neuropathy) RARE 6%
- Scleral show – showing above/below limbus
- Dystopia – one eye pivots on the same point – muscle not working – the whole eye is pushed to one side due to enlargement of the muscle
5
Q
Thyroid eye disease management
A
- Topic lubrication & steroids
- Oral immune-suppression
- Low dose radiotherapy – reduces immune system
- Soft tissue and bony decompression – surgery to make orbit bigger by removing the bone
- Upper lid lowering & lower lid elevation (need to wait for inflammation to settle)
- Squint surgery
- Disease stabilization can take up to 12 years
6
Q
PReceptus cellulitis
A
Preseptal cellulitis
* Infection of the subcutaneous tissues anterior to the orbital septum
* More common that orbital and regraded as less serious
* Severe complications such as abscess formation, meningitis and CS thrombosis may occur
* Rapid progression to orbital cellulitis may rarely occur
Presentation
* Condition manifests with a swollen, often firm, tender red eyelid that may be very severe
* Proptosis and chemosis are absent
* Visual acuity, pupils and ocular motility are unimpaired
7
Q
preceptus cellulitis treatment
A
- Oral antibiotics such as co-amoxiclav 2-3 times daily, depending on potency
- Severe infection may intravenous antibiotics
8
Q
Orbital cellulitis causes
A
- Sinusitis – 57% (sinuses are very close to the orbit)
- Lid/face infection – 28%
- Foreign body – 11%
- Haematogenous – 4%
9
Q
Orbital cellulitis - symptoms
A
- Rapid onset of pain – exacerbated by movement
- Swelling of the eye
- Malaise
- Visual impairment
- Double vision
- Commonly recent history of nasal, sinus or respiratory problems
10
Q
Orbital cellulitis signs
A
- Lid oedema & erythema
- Chemosis
- Axial proptosis if diffuse disease occurs or abaxial displacement if an abscess forms
- Decreased ocular motility
- IOP may be elevated
- Rapid vision loss due to optic nerve compression/optic neuritis/vasculitis
11
Q
Orbital cellulitis - warning signs
A
- Dilated pupil
- Marked ophthalmoplegia (paralysis of the muscles within or surrounding the eye)
- Loss of vision
- RAPD
- Papilloedema
- Perivasculitis
- Violaceous lids – violet colour
- Systemic symptoms
12
Q
Orbital cellulitis treatment
A
- Same day referral – life threating condition
- Treatment is with systemic antibiotics
- Sinus drainage is needed in only 50% of cases
- For adults – drainage of sinus/adults needed in 90% cases
13
Q
Idiopathic orbital inflammatory disease symptoms
A
- Abrupt pain
- Swelling
- Acute/subacute ocular/periocular redness
- Systemic symptoms are common in children
14
Q
Idiopathic orbital inflammatory disease signs
A
- Pyrexia (raised body temperature) common in children
- Exophthalmos
- Conjunctival injection
- Chemosis
- Motility restriction
- Can be features of optic nerve dysfunction
15
Q
Idiopathic orbital inflammatory disease treatment
A
- Observation in mild cases, in anticipation of spontaneous regression
- NSAIDS
- Systemic corticosteroids = dramatic improvement
- Orbital depot steroid
- Radiotherapy
- Surgical resection in highly resistant cases
- Generally excellent prognosis
16
Q
Orbital myosites symptoms
A
- Acute pain
- Exacerbated by eye movement
- Diplopia – onset usually in early adulthood
17
Q
Orbital myositis signs
A
- Motility restriction
- Exophthalmos
- Displacement of globe
18
Q
Orbital myosites treatment
A
- Systemic corticosteroids usually result in prompt resolution
19
Q
Dermoid cyst
A
- Choristoma derived from displacement of ectoderm to a subcutaneous location along embryonic lines of closure
- Dermoid cysts are one of the most frequently encountered orbital tumours in children
- Superficial - firm round sooth non-tender mass about 1-2cm in diameter, mobile under the skin
- Deep – proptosis, dystopia, or a mass lesion with indistinct posterior margins
- Treatment – small lesions may be observed, and inflammation can be addressed with oral steroids, excision in toto
20
Q
Lacrimal gland tumours
A
- Pleomorphic adenoma (benign mixed cell tumour) > do not biopsy, potential to become malignant, 25% of lacrimal mass lesions
- Adenoid cystic carcinoma – 23% - fourth decade of life
- Exophthalmos, downward globe displacement, ptosis, diplopia and pain as a sresult of perineural invasion
- High mortality rate
21
Q
peadiatric orbital tumours
A
- Dermoid cysts – choristoma – mass of normal tissue at abnormal location
o Painless nodule, firm, round smooth non-tender mass 1-2cm - Capillary haemangioma
o Most common, birth defect, unilateral - Rhabdomyosarcoma
o Most common soft tissue carcinoma of childhood
22
Q
Adult orbital tumours
A
- Lymphoid tumours
o Metastasize – transported to the orbit due to rich blood supply - Cavernous haemangioma
o Middle ages females mostly, most common orbital tumour in adults, probably a vascular malformation. Shows as a slow progressive unilateral proptosis - Meningiomas
23
Q
investigating orbital tumours
A
- Imaging
- Incisional or excisional biopsy
- Radiotherapy
- Chemotherapy
- Complications of treatment
24
Q
Blow out fracture
A
- Floor fractures are most common – linked to bells phenomenon
- Transmission of force
- Sudden increase in the orbital pressure from an impacting object that is greater in diameter than the orbital aperture
- Periocular signs
o Variable ecchymosis
o Oedema
o Occasionally subcutaneous emohysema - Visual function
o Acuity should be checked - Infraorbital nerve anaesthesia
o Lower lid, cheek, side of nose, upper lip, teeth, gum is very common - Diplopia
25
Blow out fractures - investigations and tumours
* CT scan
* Examination of globe
* Charting of ocular motility
* Surgical repair
