3.2 Duane's Retraction Syndrome Flashcards
(28 cards)
What are the different aetiologies with Duanes?
Innervation of LR by extra branches of the IIIrd CN in place of absent VIth nerve fibres.
Absent VIth nerve nucleus
Abnormal LR
Bursa like structure separating the tendon and trochlea
Co-contraction theory
Mechanical
Genetic abnormalities
List some of the ocular associations with Duanes
o Coloboma
o Heterochromia irides
o Microphthalmos
o Cataract
o Congenital crocodile tears
o Persistent pupillary membrane
o Marcus Gunn jaw-winking phenomenon
List some of the systemic associations with Duanes
o Goldenhar’s syndrome
o Klippel-Feil syndrome
o Hearing loss, abnormal ear formation
o Thalidomide syndrome
o Cervical spina bifida
o Wildervanck syndrome
o Moebius syndrome
What does CCDD stand for?
Congenital cranial dysinnervation disorder
What are the main elements of CCDD’s?
- Onset at birth
- Cases can be isolated or familial
- A genetic abnormality has been identified in some familial cases
- Non-progressive
- Arises from defects affecting the brainstem and cranial nerve development
What is the onset of Duanes?
Congenital
What are the classifications/types of Duanes?
Type A, B and C
Describe Duanes Type A
Limited abduction and less limited adduction (ABduction limitation >ADduction limitation)
Describe Duanes Type B
Limited abduction but normal adduction
(ABduction limitation only)
Describe Duanes Type C
Limitation of adduction exceeds limitation of abduction
(ADduction limitation > ABduction limitation)
What are the four variants of Duanes?
Vertical retraction syndrome
Congenital adduction deficit with synergistic divergence
Acquired retraction syndrome
Co-innervation with other branches of the IIIrd nerve
What is vertical retraction syndrome?
o Retraction and narrowing on elevation or depression
o Cause: Anomalous orbital structures rather than aberrant innervation.
(RARE)
What is congenital adduction deficit with synergistic divergence?
o Exotropia with marked limitation of adduction
o On attempted adduction, the eye moves further into abduction
o Also known as ‘the splits’
(RARE)
What is acquired retraction syndrome?
o Also known as ‘pseudo-Duane syndrome’
o Limitation of abduction
o Globe retraction in abduction
o Causes: trauma, systemic illness, orbital tumours
What is co-innervation with other branches of the third nerve?
o Innervation from the third nerve to both the LR and vertical muscles
o Co-innervation occurs causing an up-drift and down-drift on horizontal gaze
List features of Duanes
- Limitation of horizontal eye movements
- Abnormal head posture (to achieve field of BSV)
- Manifest strabismus when the head is straight
- Retraction of the globe on adduction with narrowing of the palpebral fissure
- Widening of the palpebral fissure on abduction
- Up shoot or down shoot on adduction
- Binocular single vision is usually present but with reduced stereo and poor convergence in some cases
- Rarely report diplopia
- Other developmental abnormalities (involving ear, eye, kidneys and genetic defects)
What are some extra orthoptic assessments to perform on Duanes patients?
o Hess chart (head kept straight and static)
o Field of BSV (head kept straight and static)
o Routine cycloplegic refraction and fundus check should be done in all cases (refractive error is neither more or less common in Duane’s when compared to the average population).
Name some differentials of Duanes
Trauma - Blow out fracture
Moebius syndrome
Congenital 6th nerve palsy
Infantile ET
What are non-surgical management options for Duanes?
o Correct any refractive error (hypermetropia may improve alignment in ET’s)
o Treat any amblyopia
o In uncommon cases of decompensation and diplopia, prisms should be trialled
When would we perform surgery on Duanes patients?
Decompensation
Moderate AHP and neck pain
Poor cosmesis (large esotropia)
What does surgery of Duanes aim to achieve/correct?
Improve field of BSV
Reduce AHP
Improve cosmesis if no BSV
What is the caveat we need to consider with surgical intervention on Duanes
AVOID SURGERY IF POSSIBLE - surgery outcome is unpredictable , results can range from no change in limitation in elevation in adduction to a complete superior oblique palsy.
What are the surgical options for Duanes type A and B (esotropia)?
- Recess one or both MR depending on angle – recommended
- Vertical muscle transposition surgery
What are the surgical options for Duanes type C (exotropia)?
- Unilateral or bilateral LR recessions
