Block 11 Flashcards
What is a strabismus
Person cannot not align both eyes simultaneously under normal conditions. It can move in, out, up, or down
Can be constant or intermittent
What are the causes of strabismus
Congenital
Accommodative ET
Abnormal visual development
Neurological
What are the types of strabismus
CN palsy
Neurological diseases
Post. Fossa tumor
Increased ICP
LR
Primary
Secondary
Tertiary action
1: abduct
2: none
3: none
MR
Primary
Secondary
Tertiary
1: adduct
2: none
3: none
SR
Primary:
Secondary:
Tertiary:
1: elevate
2: intort
3: adduct
IO
Primary
Secondary
Teritary
1: extort
2: elevate
3: abduct
IR
Primary:
Secondary:
Tertiary:
1: depress
2: extort
3: adduct
SO
Primary:
Secondary:
Tertiary:
1: intort
2: depress
3: abduct
What are the symptoms of cranial nerve paralysis
Double vision Blurry vision Decreased peripheral vision HA Dizziness
CN 3 innervates what…
SR MR IR IO Superior palpebral EW nucleus
How does a CN 3 palsy appear
Down and out
Ptosis
Dilated pupil, no accommodation
What are the common causes of CN3 palsy in children
Congenital
Vascular
Tumor
What are the common causes of CN 3 palsy in adults
Demyelination disease
Vascular
Tumor
Diabetes
What are the common causes of CN 3 palsy in elderly
Vascular
Tumor
What are some causes of CN3 palsy
Ischemic/vascular Intracranial aneurysm Neoplasm Trauma Migraine Inflammatory Infectious
What test would you do on CN 3 palsy
CH External exam VA CT (exo, hypo) EOMs Pupils NPC Accommodation testing Hess-lancaster
What palsy is most common in children
CN 4
What muscles are innervated by CN 4
SO
How does a CN 4 palsy appear
Eye is up and in
Compensatory head tilt to the opposite side of palsy
What nerve has the longest intracranial pathway
CN 4
Why can a CN 4 palsy cause ipsilateral Horner’s syndrome
Because it runs near the sympathetic fibers
What is the Horner’s syndrome triad
Miosis
Ptosis
Anhidrosis
What are common causes of CN 4 palsys in children
Abnormal development of CN4/peripheral nerves
What are the common causes of CN 4 palsy
#1 idiopathic #2 head trauma WITH loss of consciousness
What tests are performed for CN4 palsy
CH External exam CT EOMs Pupils Parks 3 step NPC Hess-Lancaster
What muscles are innervated by CN 6
LR
How does CN 6 palsy appear
Esotropia
Compensatory head turn towards the affected eye
What nerve has the longest external course through the cranium
CN 6
What injury is CN 6 susceptible to
Injury Increase ICP Mastoid infection Skull fracture Tumors
What is the presentation of CN 6 palsy
Ipsilateral paresis of LR
Convergent strabismus in temporal gaze
Lateral diplopia
Ipsilateral paresis of facial muscles
What palsy is most common in adults
CN 6
T/F the LR has 1 anterior ciliary muscle that innervates it
True
Why is the LR affected so much by ischemia
It has only one anterior ciliary muscle
What are some causes of CN 6 palsy
Trauma Aneurysm Ischemia Idiopathic Demyelination diseases Neoplasms Inflammation Meningitis
What tests are done in CN 6 palsy
CH External exam VA CT EOMs Hess-Lancaster
What is affected in Cavernous sinus palsy
CN 3, 4, V1, V2, 6, Horner’s
NOT the optic nerve
What is the number one cause of cavernous sinus palsy
Neoplasms
Carotid cavernous fistula, aneurysm, fungal infxn, inflammation
What is affected in orbital apex syndrome
CN 3, 4, v1, 6, Horner’s, Optic Nerve
What are the common causes of orbital apex syndrome
1 neoplasms
Fungal, inflammation
MR palsy causes
Exo
N>D
IR palsy
Hyper/exo
SR palsy
Bilateral
V exo pattern
IO palsy
Eso
What is affected in double elevator palsy
SR and IO of the SAME eye
How does double elevator palsy present
No elevation in abduction or adduction
Bells pheromones IS present
What is double depressor palsy (monocular depression deficiency)
IR and SO in the age eye are affected
How does double depressor syndrome appear
No depression in ab/adduction
Head is tilted down
What are causes of neurogenic palsys
Congenital Traumatic Inflammation Neoplastic Ischemic Toxic Demyelination diseases Idiopathic
Supranuclear palsy
Lesions above the oculomotor nerve nuclei
How does a supranuclear palsy appear
Gaze palsy Tonic gaze deviation Vergence anormality Saccadic/smooth pursuit disorders Nystagmus Ocular oscillations
What is internuclear palsy
Lesion of the medial longitudinal fasciculus
What are causes of internuclear palsy
MS in younger patients
Vascular in elderly
What is nuclear palsy
Unilateral CN3 with bilateral ptosis or SR underaction
Palsy of IR, IO, or MR
Browns syndrome
Bilateral CN 3- sparred levator function
What is infranuclear palsy
CN 3, 4, 6
If CN 3 is affected in infranuclear palsy how does it appear
Central pupil sparing
Peripheral with pupil
In infranuclear if the pupil is spared what caused it?
Vascular
In infranuclear if the pupil is NOT spared what casued it?
Aneurysm
What are some management tests done for strabismus
CH
CT, Hess-Lancaster, EOMs
Differential diagnosis
Additional tests (MRI, blood work)
What are the causes of strabismus
Aneurysm
Neoplasms
Ischemic
In ischemic causes how do they happen?
> 40 yoa
Sudden onset
Resolves in 3 months
Treat systemic factors
What is the first step in strabismus treatment
Glasses
Fresnel prism
What are som either treatements for strabismus besides glasses
Occlusion
Botox
Surgery
When is Botox commonly used
In CN 6 palsy
What are the side effects of Botox
Soreness at injection site Weakness in injected muscle Muscle soreness in whole body Difficulty swallowing Red rash
What is a mechanical restriction
EOM is tethered or a systemic disease reduces the elasticity of one or more muscles
Incomitant nonparetic deviations
What are some common characteristics of mechanical restrictions
Gross limitation of ocular movement in one or more gazes
Small deviation of ortho in primary
Normal binoularity vision aided by compensatory head movement
Positive forced duction testing
What tests are done for mechanical restrictions
Alternate CT Maddox rod (prism over affected eye)
Both eyes: Hirschberg/Krimsky
What is Duanes syndrome characterized by
Limitations in ABDuction, ADDuction, or both
Type 1 Duanes
Limited ABDuction
Type 2 duanes
Limited ADDuction
Type 3 duanes
Limited ABDuction and ADDuction
T/F a patient with limited abduction in the absence of a significant strabismus in primary position should be considered Duane’s syndrome until otherwise proven
True
What are some characteristics of Duanes
Congenital Unilateral No strab in primary Enopthalmos in primary A/V pattern
What is the most common onset of Duanes
Sporadic during infancy
What causes Duanes syndrome
Fibrotic LR
MR that is inserted too far posteriorly
Anomalous innervation
How is binocularity in Duanes Syndrome patients
High level
Compensatory head posture toward affected eye
Amblyopia and diplopia are rare
How is motility in Duanes syndrome
Up/downshoot of affected eye during adduction
Mimics overaction of IO and/or SO
Surgery will not help overshoot
What is the differential diagnosis of Duanes
LR palsy
- absence of retraction with adduction
- esotropic angle larger in CN6P
- rarely have vertical anomalous movements
What are the treatments for Duanes
Surgery if significant strab in primary, help head posture, improve binocular field of vision
Prism to alleviate head posture
What is Browns syndrome
Restricted elevation on adduction
What are the characteristics of Browns
Unilateral
OD>OS
Females
Constant can be intermittent
What is the cause of BRowns
Sue to thickening of the SO tendon
Cannot move through throchlea effectively
Congenital
Acquired (trauma)
May improve with time
How is motility in Browns
Restricted elevation or absence of elevation in adduction
Positive forced duction
Minimal or no vertical deviation in primary
V pattern
Audible click
Head posture: chin elevated pointed towards posterior shoulder
Mild down shoot of affected eye
No overactin of ipsilateral SO
Widening of palpebral fissure in adduction
How is binocularity in Browns
High level of bingo vision in primary
Ortho in primary
Rare amblyopia
Rare diplopia
What is the differential for Browns
IO paresis
Hypotropia in primary
Head tilt to affected side/head Turn and elevation
A pattern
Can do parks 3 step
How do you treat Browns
Most do not need treatment
Primary: surgery
Secondary: prism (BU or yoked)
vision therapy to improve elevation in adduction (no successful)
What is MG
An autoimmune NM disorder of voluntary striated muscle
Who is most often affected by MG
Females Females under 40 Men over 60 Neonatal or congenital Onset can follow stress
What is the etiology do MG
Antibodies released and block and destroy ACh receptors
There are less receptors so less nerve signals so muscle weakness
Thymus gland could be involved (immune repsonse via T cells) larger thymus is MG patients
What is the halllmark of MG
Muscle weakness that worsens after periods of activity and improves after periods of rest
What are the 2 types of MG
Generalized (whole body)
Ocular (eyes)
Generalized MG signs and symptoms
Weakness of arm and leg Muscles
Difficulty with speech, chewing, swallowing, and breathing
What are the signs and symptoms of ocular MG
Ptosis (most common) (palsy of lev.,unilateral, progressive)
Diplopia
Nystagmus moments
Saccadic abnormalities
MG causes issue with what muscles
Skeletal muscle Orbicularis oculi Masseter (cant open jaw) Sternocleidomastoid (head droop) Tongue (poor gag repsonse) Diaphragm (death)
What is MG crisis
When muscels are too weak to control breathing
What are teh most common associations of MG
Thymomas
Thymus hyperplasia
Thyroid disease
Autoimmune (rheumatoid factor)
What do you use to diagnose ocular MG
Old photos
EOMs>fatigue
- Ptosis with prolonged up gaze or rapid opening and closing of eye
- Conan’s lid twitch (down gaze, the upper lid will twitch as patient looks up)
Ice test (2-5 minutes, ptosis will get improve) (cold makes the ACh breaks down much slower, there will be more ACH available)
What is the clinical pearl of MG
Presence of an inconsistent deviation along with ptosis and restricted ocular motility
What are some further tests that can be done in MG
Electromyography
Sleep test
Systemic antiAChase agents (tension and neostigmine test)
Pysical/Neuro exam
Blood test
MRI/CT scan
Pulmonary function
How can you treat culver MG
Occlusion**
Prism (not successful)
Strabismus/ptosis surgery (not common)
Spontaneous remission occurs in 30% of cases
What is teh systemic treatment for MG
AntiAChase agents Immunosuppressive drugs Thymectomy Plasmapheresis (severe) IV immunoglobulin (severe)
No cure, treat signs and symptoms
What is Graves Disease
Autoimmune disorder that results from overproduction of thyroid hormone
Hyperthyroidism
What are teh 2 types of Graves
Graves dermopathy
Graves Ophthalmopathy
What are the signs and symptoms of Graves
Enlargement of thyroid Weight loss He’s sensitivity Change in menstruation Fatigue Thick red skin Tachycardia Budging eye ** ED
What is Graves ophthalmopathy
Autoimmune inflammation of orbital tissue and muscles
Most common cause of spontaneous diplopia in middle aged people
What is teh histology of Graves Ophthalmopathy
Enlargement of EOMs
Reduced elasticity and motility
Affected EOMs produces an incomitant deviation
What are the characteristics of Graves Ophthalmopathy
Bilateral
Females
Younger than 40
Inherited
What are the risk factors for Graves Ophthalmopathy
Stress
Pregnancy
Autoimmune
Smoking
What are common signs of Graves Ophthalmopathy
Periorbital congestion Pro ptosis Lid lag Exophthalmos Optic neuropathy Impaired ocular motility
Dry gritty sensation, photophobia, tearing, double vision, pressure behind eyes, vison loss
How is motility affected in Graves Ophthalmopathy
Positive forced duction IR most commonly affected LR is least affected (IR>MR>SR>LR) In severe cases eye is tethered down There will be a restriction in upgaze and hypotropia of affected eye
What is Graves ophthalmopathy often mistaken for
SR paresis
What is eye alignment in Graves
Diplopia worse in the morning
Restriction of elevation and abduction (hypotropia)
Could also have ET, XT, cyclotorsion)
How do you diagnose Graves Ophthalmopathy
Tonometry (increased in up gaze)
Hertel exophthalmometer
Slit lamp (keratopathy)
Optic nerve eval (optic neuropathy)
CT of orbits, thyroid fxn tests (T3/T4/TSH)
What is the prognosis for Graves Ophthalmopathy
Spontaneous improvement
Deviation may persist even with control
Improvement in motility can occur with decreased orbital edema
What are the treatment options for Graves Ophthalmoscopy
Prism (Fresnel)
Surgery (in significant ocular deviations/restrictions)
Artificial tears
Cold compress for eyelid edema
Smoking cessation
What is the systemic treatment for Graves ophthalmopathy
Radioactive iodine therapy
Corticosteroids
Anti-thyroid drugs
Thyroidectomy
These will not always improve ocular symptoms)
Ocular signs may worsen for 3-6 months)
Versions
Conjugate movements of both eyes
Ductions
One eye
How do you record versions
SAFE
How do you record ductions
Record as a percent of normal
What is uncrossed diplopia
ESO
Light hits nasal retina
What is uncrossed diplopia
EXO
Light hits temporal retina
Crosses the VA of the fixating eye
Maddox Rod
Red Light through white dot
Ortho
Maddox Rod
Red Line to the right
Eso
Uncrossed diplopia
Maddox Rod
Red line to the left
Exo
Crossed diplopia
Maddox Rod
Red line below
R hyper
Maddox Rod
Red line above
L hyper
What is fibrosis syndrome
Tissues of EOMs are abnormal
Replaced with fibrotic tissue
What are some presentations of fibrosis syndrome
Severely restricted eye movements
Ptosis
Can elevation
How many muscles are affected in fibrosis syndrome
All muscles or just 1
What is the most common muscle affected by fibrosis syndrome?
How does it appear
IR
Hypodeviation 20-30 degrees below horizontal
What is the onset of fibrosis syndrome
Congenital (Autosomal dominant)
Acquired (sporadic)
Stable, non-progressive
How is bino in fibrosis syndrome
Poor
What can occur in fibrosis syndrome
Poor versions and ductions Ptosis Amblyopia Assymmetrical Cosmesis Reduced stereopsis
What are the treatments for fibrosis syndrome
Amblyopia therapy
Manage ptosis
Manage abnormal head movement
Difficult to treat with surgery
