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44 Questions

What is the primary treatment for Ocular Myositis?

Corticosteroids

The ______ barked

dog

What is the main cause of Dissociated Vertical Deviation?

Reduced light entering the eye

Pseudostrabismus is a condition where there is a manifest deviation of the visual axes.

False

What is the purpose of investigating binocular single vision and fusional control in the management of Pseudostrabismus?

To determine if further treatment is needed if associated with true strabismus

The _______________ muscle is responsible for torsion.

Oblique

What is a common sign of torsion?

Disc appears displaced and intorted or extorted in relation to the fovea

Match the following terms with their definitions:

Pseudostrabismus = Appearance of strabismus when no manifest deviation of the visual axes is present Dissociated Vertical Deviation = Spontaneous elevation of either eye intermittently when the stimulus to fixate is reduced Torsion = Rotation of the eye around its anteroposterior axis

Anterior transposition of IO is a surgical procedure used to treat Dissociated Vertical Deviation.

True

What is the primary concern when diagnosing muscle inflammation/swelling on a CT scan?

Rhabdomyosarcoma

True or False: A disorder of supranuclear pathways can result in diplopia.

False

What is the purpose of the horizontal gaze centre in the midbrain?

The horizontal gaze centre controls horizontal movement to the same side and projects to the ipsilateral abducens nucleus and to the medial rectus sub nucleus of the third nerve on the opposite side via MLF.

The _______________________ pathway lies at the region of the thalamus and midbrain.

vertical

Match the following brain areas with their functions in eye movement control:

Frontal pre-motor area = Initiates saccades Occipito-parietal area = Initiates pursuits Vestibular nuclei in the pons = Initiates VOR

What is the typical latency or delay of the ocular motor system's response to a saccadic eye movement?

100-300ms

True or False: The basal ganglia and thalamus are involved in smooth pursuit control.

True

What is the typical presentation of Double Elevation Palsy?

Limited elevation of one eye in both adduction and abduction, often with a congenital origin.

The _______________________ test may show full passive movement (negative result) or it may be positive in Double Elevation Palsy.

Forced duction

What is the primary concern when diagnosing muscle inflammation/swelling on a CT scan?

Rhabdomyosarcoma

A disorder of supranuclear pathways can result in diplopia.

False

What is the function of the middle temporal visual area in the superior temporal sulcus?

Encoding speed and direction of moving stimuli

The horizontal gaze centre projects to the ipsilateral abducens nucleus and to the _______________ sub nucleus of third nerve on opposite side via MLF.

medial rectus

What is the typical presentation of Double Elevation Palsy?

Limited elevation of one eye in both adduction and abduction

Match the following brain areas with their functions in eye movement control:

Frontal eye fields = Aid programming of predictive pursuit movements, initiation and maintenance Occipital cortex = Visual information processing Thalamus = Aid smooth pursuit control Parietal cortex = Motion processing

The basal ganglia and thalamus are involved in saccade control.

False

What is the typical latency or delay of the ocular motor system's response to a saccadic eye movement?

100-300ms

The vertical pathway lies at the region of the _______________ and midbrain.

thalamus

What is the function of the superior temporal sulcus in smooth pursuit eye movement?

Encoding speed and direction of moving stimuli

What is the primary goal of surgery in Dissociated Vertical Deviation?

To reduce frequent spontaneous elevation of one or both eyes

True or False: Ptosis can give the appearance of a horizontal deviation.

False

What is the purpose of investigating binocular single vision and fusional control in the management of Pseudostrabismus?

To determine if further treatment is needed as indicated

The _______________ muscle is responsible for torsion.

Oblique

What is a common sign of torsion?

Intorted or extorted disc

Match the following terms with their definitions:

Pseudostrabismus = Appearance of strabismus when no manifest deviation of the visual axes is present Dissociated Vertical Deviation = Spontaneous elevation of either eye intermittently when the stimulus to fixate is reduced Torsion = Rotation of the eye around its anteroposterior axis

The fovea-optic disc relationship is observed in congenital cases to measure torsion _______.

objectively

True or False: A wide IPD gives the appearance of a convergent deviation.

False

What is the characteristic feature of CPEO Myositis?

Bilateral ptosis and orbicularis weakness

Kearns Sayre syndrome is associated with CPEO Myositis.

True

What is the typical age of onset for CPEO Myositis in Kearns Sayre syndrome?

before the age of 20 years

CPEO Myositis is a type of mitochondrial disorder associated with ____________.

Kearns Sayre syndrome

What is the primary investigation for Ocular Myositis?

Case history

Ocular Myositis is a chronic condition that requires lifelong treatment.

False

Match the following clinical features with the correct condition:

Painful diplopia = Ocular Myositis Bilateral ptosis = CPEO Myositis Proptosis = Ocular Myositis Normal pupils = CPEO Myositis

What is the primary management strategy for Ocular Myositis?

Corticosteroids

Study Notes

CPEO Myositis

  • Chronic progressive external ophthalmoplegia (CPEO) is a mitochondrial disorder associated with Kearns-Sayre Syndrome
  • Clinical features:
    • Progressive symmetrical loss of motility, with upgaze being the first to be affected
    • Bilateral ptosis and orbicularis weakness
    • Normal pupils and accommodation
    • Diplopia is not usually complained of due to symmetrical and slow progression
    • Final stages have virtually no eye movements with a positive forced duction test (FDT) due to secondary fibrosis
  • Limitation of eye movement
  • Kearns-Sayre Syndrome:
    • CPEO in childhood (before the age of 20 years)
    • Fine pigmentary retinopathy
    • Clinical features: heart conduction block, deafness, cerebellar ataxia
  • Management:
    • Funduscopy
    • ECG
    • Orthoptic assessment (including UFOF, ptosis preps/Fresnel's)

Ocular Myositis

  • Inflammation of one or more extraocular muscles (EOMs) resulting in impairment of function
  • Sudden onset, can be acute or chronic (acute onset can become chronic)
  • Clinical features:
    • Painful diplopia
    • Acute pain (periocular pain)
    • Proptosis
    • Oedema (periorbital/chemosis/swelling of the conjunctiva/eyelid swelling and redness)
    • Underlying inflammatory disease/autoimmune disorder
    • Restricted ocular motility and strabismus
  • Investigations:
    • Case history (painful diplopia and photophobia)
    • Visual acuity (reduced)
    • Cover test (type of strabismus relates to the affected EOM)
    • Ocular motility (exophthalmos and lid oedema is evident in multiple EOM paresis)
  • Diagnosis and management:
    • Corticosteroids (highly effective in medical management of inflammation)
    • Surgery may be required for residual restrictive strabismus
    • Prisms may be required
    • Consider Botox
    • Self-limiting, usually resolves within 8 weeks
    • CT scan shows marked inflammation/swelling of one or more muscles, including the tendon
    • Ensure it is not Rhabdomyosarcoma, a highly malignant tumor that presents in childhood, usually associated with acute proptosis and strabismus

Supra/Infra/Inter Pathways

Supranuclear Disorders

  • Signals controlling ocular movement are initiated in the cerebral hemispheres and then transmitted to the gaze centres in the midbrain and oculomotor nuclei
  • Supra-nuclear neuronal pathways conduct impulses from cerebral hemispheres to gaze centres
  • Control saccades, pursuits, and vestibular
  • Disorder results in palsies of conjugate (connected) movement

Gaze Palsies

  • Inability to make conjugate eye movements in one direction
  • Does not cause diplopia as visual axis usually remains parallel
  • Investigating each reflex and conjugate movement makes it possible to establish where the lesion lies
  • E.g. frontal lesion = unilateral saccadic palsies, occipital lesion = unilateral pursuit palsies

Other

  • Double elevation palsy: often congenital, presumed to be caused by a supranuclear defect
  • Dissociated vertical deviation: spontaneous elevation of either eye intermittently when the stimulus to fixate is reduced
  • Pseudostrabismus: appearance of strabismus when no manifest deviation of the visual axes is present
  • Torsion: oblique muscle is responsible, can be measured objectively or subjectively

CPEO Myositis

  • Chronic progressive external ophthalmoplegia (CPEO) is a mitochondrial disorder associated with Kearns-Sayre Syndrome
  • Clinical features:
    • Progressive symmetrical loss of motility, with upgaze being the first to be affected
    • Bilateral ptosis and orbicularis weakness
    • Normal pupils and accommodation
    • Diplopia is not usually complained of due to symmetrical and slow progression
    • Final stages have virtually no eye movements with a positive forced duction test (FDT) due to secondary fibrosis
  • Limitation of eye movement
  • Kearns-Sayre Syndrome:
    • CPEO in childhood (before the age of 20 years)
    • Fine pigmentary retinopathy
    • Clinical features: heart conduction block, deafness, cerebellar ataxia
  • Management:
    • Funduscopy
    • ECG
    • Orthoptic assessment (including UFOF, ptosis preps/Fresnel's)

Ocular Myositis

  • Inflammation of one or more extraocular muscles (EOMs) resulting in impairment of function
  • Sudden onset, can be acute or chronic (acute onset can become chronic)
  • Clinical features:
    • Painful diplopia
    • Acute pain (periocular pain)
    • Proptosis
    • Oedema (periorbital/chemosis/swelling of the conjunctiva/eyelid swelling and redness)
    • Underlying inflammatory disease/autoimmune disorder
    • Restricted ocular motility and strabismus
  • Investigations:
    • Case history (painful diplopia and photophobia)
    • Visual acuity (reduced)
    • Cover test (type of strabismus relates to the affected EOM)
    • Ocular motility (exophthalmos and lid oedema is evident in multiple EOM paresis)
  • Diagnosis and management:
    • Corticosteroids (highly effective in medical management of inflammation)
    • Surgery may be required for residual restrictive strabismus
    • Prisms may be required
    • Consider Botox
    • Self-limiting, usually resolves within 8 weeks
    • CT scan shows marked inflammation/swelling of one or more muscles, including the tendon
    • Ensure it is not Rhabdomyosarcoma, a highly malignant tumor that presents in childhood, usually associated with acute proptosis and strabismus

Supra/Infra/Inter Pathways

Supranuclear Disorders

  • Signals controlling ocular movement are initiated in the cerebral hemispheres and then transmitted to the gaze centres in the midbrain and oculomotor nuclei
  • Supra-nuclear neuronal pathways conduct impulses from cerebral hemispheres to gaze centres
  • Control saccades, pursuits, and vestibular
  • Disorder results in palsies of conjugate (connected) movement

Gaze Palsies

  • Inability to make conjugate eye movements in one direction
  • Does not cause diplopia as visual axis usually remains parallel
  • Investigating each reflex and conjugate movement makes it possible to establish where the lesion lies
  • E.g. frontal lesion = unilateral saccadic palsies, occipital lesion = unilateral pursuit palsies

Other

  • Double elevation palsy: often congenital, presumed to be caused by a supranuclear defect
  • Dissociated vertical deviation: spontaneous elevation of either eye intermittently when the stimulus to fixate is reduced
  • Pseudostrabismus: appearance of strabismus when no manifest deviation of the visual axes is present
  • Torsion: oblique muscle is responsible, can be measured objectively or subjectively

Learn about Chronic Progressive External Ophthalmoplegia, a mitochondrial disorder associated with Kearns-Sayre Syndrome. Understand its clinical features, including progressive symmetrical loss of motility, bilateral ptosis, and more.

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