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- rare, transient involuntary spasm of EOM resulting in strab
- often hx of radiotherapy
Monocular elevation deficiency?
- congenital deficiency of monocular elevation in primary and abad-duction
- hypotropia of deficit eye
- SR palsy and IR contracture
- assoc: pseudoptosis and jaw winking
- tx: surgery
Treatment for nerve palsies
- ischemic: spontaneous resolving
- vasculopathy: GP to treat underlying cause
- aneurysm/compression: refer for MRI
- GCA: ESR and c-reactive protein
- trauma: CT
- nonsurgical: fresnel prism, botox, alt occlusion
Duane's type 1, 2 and 3?
- type 1: abduction limited + widen, adduction- globe retraction and narrowing, ST
- type 2: abduction widening, adduction- limited, retraction and narrow, XT
- type 3: abd and ad limited
- SO sheath syndrome
- vert diplopia in elevation
- hypertropia of affected eye- head tilt backwards
- Features: elevation worse ad, less primary, ok in ab, no SO overaction, V pattern, +ve forced duction testing
What is the cause of myasthenia gravis?
ACH receptor site antibodies reduce effectiveness of ACh- muscles become exhausted
What are 3 key ocular signs of myasthenia gravis?
- 1. Ptosis: bilateral, variable, switches eye, worse end of day
- 2. diplopia: vertical, variable, intermittent
- 3. obicularis weakness: cant prevent examiner from closing eyes, incomplete closure- exposure keratitis
What are the 3 types of lid retraction in myasthenia gravis?
- 1. cogan's lid twitch: prolonged downgaze, primary gaze will reveal upper lid twitch
- 2. transient lid retraction: prolonged upgaze
- 3. paraodixical sign: ptotic eye fixating- contralateral lid retraction, if lift lid of ptotic eye- innvervation will disappear
What are the goals of tx for myasthenia gravis?
- relief from diplopia and obstructed vision
- tx: prism, occlusion, ptosis crutch
Chronic progressive external ophthalmaplegia?
progressive systemic loss of ocular motility
What are some features of CPEO?
- symmetrical ptosis
- obicularis weakness
- gradually- no ocular motility
Management of CPEO?
- ECG: heart problems
- Prism: early maybe diplopic
- Ptosis crutches or surgery: avoid overwidening- px cant elevate eyes
Orbital myositis and pseudotumour?
- myositis: inflammatory swelling of one or more EOM
- pseudotumour: muscles + other structures
Features of an orbital myositis?
- limitation of movement- paretic in direction of muscle
- pain worse with eye movement
- lidswelling, redness, proptosis
Management of orbital myositis?
- self limiting
Strabismus fixus features?
- eyes are tethered in extreme position of gaze
- head turn to fixate with preferred eye
- ON blood supply strangulated
Strab fixus tx?
- surgery at early age
- ocular motility still severely limited
- but cosmesis is improved
Orbital blow out fracture sequelae?
- fracture of orbital floor - usually anterior and nasal floor bone are the thinnest
- orbital contents can prolapse into maxillary sinus
- orbita fat, IO, IR can be entrapped
- hypo in primary
Signs and sx of orbital blow out fracture?
- eye movement- limited depression and elevation
- pain- if gaze away from lesion site
Immediately after orbital blow out injury?
- swelling and ecchymosis of orbital tissue
- swelling subsides 4-6W
- CT/Xray: restricted eye movements due to: swelling, hb, entrapment
Immediate investigation of orbital blow out fracture?
- head posture
- Hess chart
- measurement of deviation
- CT scan
Management of orbital blow out fracture?
monitor 2-3 days 1st few weeks
What to look out for after swelling subsides?
- Macular edema
- Retinal detachment
- Ocular motor palsies
- Angle recession
- Iris sphincte rrupture
- Lens subluxation
- Choroidal rupture
Treatment of orbital blow out fracture?
- ice pack first few days
- broad spectrum ab- prophylaxis
- nasal decongestants
Early surgery for orbital blow out fracture?
- sx diplopia
- positive forced duction
- entrapped tissue
- no improvement after 7-14 days
Other indications of surgery?
- early enophthalmos >3mm
- significant globe ptosis
- significant inferior displacement
Conservative orbital fracture managment indications?
- normal eye movements
- no entrapment
- small fractures
- small enophthalmos