BV 11 - Myo neuro mechanical
Card Set Information
BV 11 - Myo neuro mechanical
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
: pseudoptosis and jaw winking
Treatment for nerve palsies
: spontaneous resolving
: GP to treat underlying cause
: refer for MRI
: ESR and c-reactive protein
: fresnel prism, botox, alt occlusion
Duane's type 1, 2 and 3?
: abduction limited + widen, adduction- globe retraction and narrowing, ST
: abduction widening, adduction- limited, retraction and narrow, XT
: abd and ad limited
SO sheath syndrome
vert diplopia in elevation
hypertropia of affected eye- head tilt backwards
: 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?
: bilateral, variable, switches eye, worse end of day
: 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
: prism, occlusion, ptosis crutch
Chronic progressive external ophthalmaplegia?
progressive systemic loss of ocular motility
What are some features of CPEO?
gradually- no ocular motility
Management of CPEO?
: heart problems
: early maybe diplopic
Ptosis crutches or surgery
: avoid overwidening- px cant elevate eyes
Orbital myositis and pseudotumour?
: inflammatory swelling of one or more EOM
: 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?
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
: restricted eye movements due to: swelling, hb, entrapment
Immediate investigation of orbital blow out fracture?
measurement of deviation
Management of orbital blow out fracture?
monitor 2-3 days 1st few weeks
What to look out for after swelling subsides?
Ocular motor palsies
Iris sphincte rrupture
Treatment of orbital blow out fracture?
ice pack first few days
broad spectrum ab- prophylaxis
Early surgery for orbital blow out fracture?
positive forced duction
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