6.7 Duane Syndrome

Definition

  • Hallmark: Retraction of the globe on attempted adduction (co-contraction of lateral and medial rectus), resulting in narrowing of palpebral fissure.

Aetiology

Congenital cranial dysinnervation disorder.

  1. CNVI nucleus absent
  2. CNIII nucleus innervates LR (inappropriately) and MR (appropriately)

95% are sporadic (rarely autosomal dominant).

(Huber) Classification

Type I (>50%)

Limited AbDuction ± Esotropia in primary (mostly straight)

Type II

Limited ADDuction ± Exotropia in primary

Type III

Limited AbDuction and ADDuction ± Esotropia in primary

NB: Count the number of D’s to determine the type!
Can also be classified: esotropic, exotropic, or orthotropic Duane Syndrome

Examination Structure

1. Visual Acuity (Best Corrected)

  • Amblyopia uncommon

2. Spectacles

3. Inspection

  1. Abnormal head position- head turn / tilt to the same side (in Type 1)
  2. Hirschberg (Pupil margin = 15°, Iris margin = 30°) - ± small esotropia (in Type 1)
  3. (Lids often normal in primary, close on attempted adduction)
  4. (Pupils normal)
  5. Inspect for systemic associations (ears, face, neck etc. - see below)
Figure 6.7.1a Left Duane Syndrome (Type III)

Figure 6.7.1
Left Duane Syndrome (Type III)
A: Limited adduction of the left eye. Not narrowing of the left palpebral fissure.

Figure 6.7.1b Left Duane Syndrome (Type III)

Figure 6.7.1
Left Duane Syndrome (Type III)

B: Eyes straight in primary.

Figure 6.7.1c Left Duane Syndrome (Type III)

Figure 6.7.1
Left Duane Syndrome (Type III)
C: Limited abduction of the left eye. No narrowing of the palpebral fissure.

4. Cover-Testing

  • Often straight in primary despite marked abduction deficit (in Type 1)

5. Ocular Rotations

  • ~ 85% Unilateral
  • Hallmark: Retraction of the globe on attempted adduction (co-contraction of lateral and medial recti), resulting in narrowing of palpebral fissure
  • ± Upshoot / Downshoot in adduction

6. Systemic Associations? (~30% of Patients)

Duane syndrome can be associated with:

Goldenhar Syndrome
“LUMPED”

  • L ipodermoid
  • U pper lid colobomas
  • M icrophthalmia, Microsomia (hemifacial)
  • P reauricular skin tags
  • E pibulbar dermoid / Ear anomalies
  • D uane syndrome

Wildervanck Syndrome

  • Congenital Deafness
  • Fused cervical vertebrae (Klippel-Fiel anomaly)

Duane Radial Dysplasia Syndrome

  • Radial anomalies

Differential Diagnosis

CNVI palsy:

  1. Diplopia
  2. Marked ET in primary (for degree of abduction deficit)
  3. No retraction (can be difficult to appreciate in infant)
  4. Deviation greater for distance than near

Management

A. Treat Amblyopia / Refractive Error

  • Amblyopia is present in up to 15% of patients and is usually secondary to anisometropia / refractive error rather than the strabismus.

B. Surgical

Indications (Try to Avoid!)
  1. Abnormal head posture (NB: This actually protects against amblyopia!)
  2. Cosmetically unacceptable esotropia in primary, retraction, upshoot / downshoots

Surgery will not restore normal eye movements.

Operation

Do not resect as this will worsen retraction.

1. Type I with Esotropia

  • Ipsilateral MR recession or
  • Bilateral MR recession (if >30ΔET)
  • Avoid over recession of the MR as this will result in impaired adduction.
  • ±Ipsilateral LR
    • Large recession or fix to orbital all (for globe retraction)
    • Y split (for up / downshoots)
    • Transposition surgery (for limited abduction)

2. Type II with Exotropia

  • Recession of LR or
  • Bilateral LR recession (if >20ΔXT)

          

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