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Clinical Ophthalmology > Orbit > Flashcards

Orbit Flashcards

1
Q

Orbit

A
  • Protect, support and maximise function of the eye
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2
Q

Orbit Anatomy

A
  • Orbit is surrounded by orbital bones
  • Orbital fat fills space between nerves and muscles - acts as a cushion
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3
Q

Clinical Features

A
  • Proptosis (bulging of the eye)
  • Reduction in VA
  • Pain
  • Diplopia
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4
Q

Clinical Evaluation

A
  • Complete ophthalmic examination
  • Careful H&S, including time course of the disease, past trauma, ocular surgery and systemic illnesses
  • Assessment of VA, VF, anterior and posterior segment evaluation, and external periorbital inspection
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5
Q

Investiagations

A
  • Imaging (CT/MRI/US)
  • Systemic investigations depending on clinical suspicion (e.g. blood tests such as thyroid function tests)
  • CT - good for bone abnormalities
  • MRI - good for soft tissues
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6
Q

Diffuse Idiopathic Orbital Inflammation Symptoms

A
  • typically unilateral in adults but can be bilateral in children
  • abrupt pain
  • diplopia
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7
Q

Diffuse Idiopathic Orbital Inflammation - Signs

A
  • Ocular and periocular redness
  • Conjunctival injection
  • Chemosis
  • Lid oedema
  • Proptosis
  • Exophthalmos
  • Motility restriction
  • No systemic manifestations (systemic symptoms common in children)
  • Palpable mass detected in 50% of cases
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8
Q

Diffuse Idiopathic Orbital Inflammation - Management

A
  • Observation for mild disease, in anticipation of remission
  • Systemic corticosteroids typically result in a dramatic improvement
    Prognosis generally excellent
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9
Q

Myositis

A
  • Acute to subacute idiopathic inflammation of the EOM muscles
  • Usually connected/related to other systemic diseases such as rheumatoid arthritis
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10
Q

Myositis Symptoms

A
  • Onset - usually early adulthood
  • Pain (worsened by eye movement)
  • Motility restriction
  • Diplopia
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11
Q

Myositis Signs

A
  • More subtle than IOI (above)
  • Lid oedema
  • Ptosis
  • Chemosis
  • Exophthalmos
  • Displacement of the globe
  • Vascular injection over affected muscle
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12
Q

Myositis Management

A
  • Aim - relieve discomfort and dysfunction
  • Systemic corticosteroids
  • Recurrence seen in 50%
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13
Q

Acute Dacryoadenitis

A
  • May be idiopathic or due to viral infection
  • Can be bilateral
  • Presentation in acute disease is with rapid onset of discomfort in region of lacrimal gland
  • May have increase/decrease in LG secretion, tender LG
  • Possible chemosis
  • Discharge may be reported
  • Swelling of lateral aspect of eyelid (s-shaped ptosis)
  • Occasionally proptosis
  • Treatment varies but not required in many cases
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14
Q

Orbital Cellulitis

A
  • Bacterial infection of tissue POSTERIOR to orbital septum
  • May develop from preseptal cellulitis
  • Main causes:
    • Sinusitis
    • Lid or face infection
    • Foreign body
    • hordeolum
    • dental abscess
    • Haematogenous
  • Can spread fast, especially in children
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15
Q

Orbital Cellulitis Symptoms

A
  • Sudden onset (more rapid than preseptal), unilateral
  • Pain
  • Chemosis
  • Abaxial displacement (if abscess forms)
  • Possibly raised IOP
  • Systemic symptoms such as a fever or feeling very unwell
  • Rapid loss of vision may occur from:
    • Optic nerve compression
      • Reduced VA
      • Impaired colour vision
      • RAPD
      • Make this almost certain
    • Optic neuritis
    • Vasculitis
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16
Q

Orbital Cellulitis Signs

A
  • Lid oedema and erythema (redness)
  • Dilated pupil
  • Motility - restricted range of movements, pain and diplopia reported
  • Proptosis (if diffuse disease occurs)
  • Marked ophthalmoplegia (weakness of EOM muscles?)
  • RAPD in the affected eye
  • Impaired colour vision
  • Papilledema
  • Perivasculitis
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17
Q

Orbital Cellulitis Management

A
  • Children - systemic antibiotics, sinus drainage only needed in 50% of cases
  • Adults - sinus and abscess drainage needed in 90% of cases
  • urgent/same day referral
18
Q

Preseptal Cellulitis

A
  • Bacterial infection of tissue ANTERIOR to the orbital septum
  • Bacteria may spread from nearby site:
    • Ocular (e.g. hordeolum, conjunctivitis)
    • Trauma (e.g. tree branch, insect bite)
  • May be spread of more remote infection:
    • Sinusitis
    • Middle ear infection
  • Less common and less severe than orbital
19
Q

Preseptal Cellulitis Symptoms

A
  • Most common in children (<10 yrs)
  • Typically unilateral
  • Swelling and redness of eyelids (tender eyelids also)
  • Pyrexia (fever, raised temp)
  • Malaise (general unwell feeling)
  • Irritability in children
20
Q

Preseptal Cellulitis Signs

A
  • Erythema (redness) of skin surrounding eye
  • Warm skin surrounding eye
  • Tender ocular region
  • Eyelid oedema
    • Increased weight of upper lid may cause ptosis
    • Narrowed palpebral aperture
  • CT scan - useful to exclude orbital cellulitis
21
Q

Preseptal Cellulitis Management

A
  • Risk of mis diagnosing orbital cellulitis as preseptal
  • Preseptal can progress to orbital in children
  • Emergency referral to ophthalmologist (telephone call)
  • IP optometrists can prescribe oral antibacterial drugs for adults if diagnosis is not in doubt
22
Q

Orbital vs Preseptal

A
  • Orbital more severe than preseptal
  • Orbital more sudden onset than preseptal
  • No proptosis and chemosis in preseptal
  • VA, pupil reaction, ocular motility unimpaired in preseptal
23
Q

Rhino-orbital Mucormycosis

A
  • Aggressive rare fungal infection
  • Acquired by inhalation of spores giving rise to an upper respiratory infection
  • Spreads to sinuses, orbit and brain
24
Q

Rhino-orbital Mucormycosis Symptoms

A
  • Gradual onset facial and periorbital swelling
  • Diplopia
  • Vision loss
25
Q

Rhino-orbital Mucormycosis Signs

A
  • Similar to orbital cellulitis
  • But less acute and slower progression
  • Complications include:
    • Retinal vascular occlusion
    • Multiple CN palsies
    • Cerebrovascular occlusion
26
Q

Rhino-orbital Mucormycosis Management

A
  • Correction of underlying metabolic defect if possible
  • Intravenous antifungal treatment
27
Q

Lacrimal Gland Tumours

A
  • Infiltrative processes (such as inflammatory disease and lymphoma)
  • Structural disorders (such as cysts)
  • Epithelial tumours represent 20-25% of all LG lesions
  • Almost all LG lesions result in a mass effect, with swelling of the lateral eyelid and often a downward and medial displacement of the globe
  • Inflammation causes:
    • Pain
    • Chemosis
    • Oedema
28
Q

Lacrimal Gland Tumours - Pleomorphic Adenoma & Adenoid Cystoid Carcinoma

A
  • Pleomorphic adenoma (benign mixed cell tumour) - do not biopsy, potential to become malignant, 25% of lacrimal mass lesions
  • Adenoid cystoid carcinoma - 23% commonly in the fourth decade of life
29
Q

Lacrimal Gland Tumours signs/symptoms

A
  • Exophthalmos
  • Downward globe displacement
  • Ptosis
  • Diplopia
  • Pain as a result of perineural invasion
  • Treatment involves surgical incision
  • High mortality rate
30
Q

Paediatric Orbital Tumours

A
  • Dermoid cysts (benign)
  • Capillary haemangioma (most common)
  • Rhabdomyosarcoma (aggressive, tend to be fatal)
31
Q

Adult Orbital Tumours

A
  • Lymphoid tumours
  • Cavernous haemangioma
  • Meningiomas
32
Q

Orbital Tumours Investigation and Treatment

A
  • Imaging
  • Incisional or excisional biopsy
  • Radiotherapy
  • Chemotherapy
  • Complication of treatments
33
Q

Optic Nerve Glioma

A
  • Typically affects children
  • Prognosis variable
34
Q

Optic Nerve Glioma - Symptoms

A
  • Slowly progressive visual loss
  • Followed by proptosis (sequence may be reversed)
35
Q

Optic Nerve Glioma - Signs

A
  • Proptosis
  • ONH initially swollen, becomes atrophic (loss of nerve fibres?)
  • CRVO often seen
  • Intracranial spread to chiasm and hypothalamus may develop
36
Q

Optic Nerve Glioma Management

A
  • Resection means all vision in operated eye will be lost, as tumour is intrinsic to ON
  • Observation in px’s where tumour is confined to orbit, especially if good vision and no significant cosmetic impairment
  • Surgical excision with preservation of the globe for those with large/growing tumours
  • Radiotherapy may be combined with chemotherapy for tumours that preclude surgical excision
37
Q

Optic Nerve Sheath Meningioma

A
  • Benign tumour
  • Tumour may invade ON, or encircle it
  • Less common than optic nerve gliomas
  • Typically affect middle aged women
  • Prognosis good in adults, although tumour may be more aggressive in children
38
Q

Optic Nerve Meningioma Symptoms

A
  • Gradual visual impairment in one eye
  • Transient obscuration of vision may occur
39
Q

Optic Nerve Meningioma Signs

A
  • Visual loss
  • Optic atrophy
  • Opticociliary shunt vessels
  • Simultaneous occurrence of all 3 (above) uncommon
  • Motility defects (particularly in upgaze)
  • Proptosis
40
Q

Optic Nerve Meningioma Management

A
  • May not be required for middle aged px with slow growing tumour
  • Excision for aggressive tumour, especially if eye is blind or risk of intracranial extension
41
Q

Orbital Trauma Signs

A
  • Orbital floor fractures most common
  • Oedema and ecchymosis of the eyelids and periorbital region
  • Diplopia, enophthalmos (sunken eye), or hypoesthesia (lack of sensation) of the cheek and gum
42
Q

Orbital Trauma - Investigation & Treatment

A
  • CT scan
  • Examination of globe
  • Charting of ocular motility
  • Surgical repair (orbital floor)

Clinical Ophthalmology (10 decks)

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