Duane Syndrome

Duane Syndrome Types

Duane Syndrome is classified into three types based on which eye movements are affected. The classification was developed by Huber in 1974 based on electromyographic studies.

Type 1 — Limited Abduction

Most common (~78% of cases)

What happens: The affected eye has significantly limited or absent ability to move outward (away from the nose). Movement inward (toward the nose) is normal or near-normal.

Globe retraction: When attempting to look inward, the eyeball retracts into the socket, and the eyelid opening narrows.

In daily life: People with Type 1 often develop a slight head turn toward the affected side to compensate, maintaining good binocular vision in their functional range.

Type 2 — Limited Adduction

Less common (~7% of cases)

What happens: The affected eye has limited ability to move inward (toward the nose). Outward movement is normal or near-normal.

Globe retraction: Retraction occurs when attempting to look inward, similar to Type 1.

In daily life: Head turns may be adopted to compensate. This type is sometimes confused with other forms of strabismus.

Type 3 — Limited Both Directions

Least common (~15% of cases)

What happens: The affected eye has limited movement in both directions — inward and outward.

Globe retraction: Retraction may occur when attempting to look in either direction.

In daily life: This type may present with a more notable head position. The degree of limitation can vary significantly.

Common Features Across All Types

  • Globe retraction: The hallmark feature. When the eye tries to adduct (look inward), the eyeball pulls back into the orbit.
  • Upshoot and downshoot: Abnormal vertical eye movements that occur during attempted adduction, caused by co-contraction of horizontal eye muscles.
  • Palpebral fissure narrowing: The eyelid opening becomes smaller during certain eye movements due to the globe retraction.
  • Compensatory head turn: A natural adaptation that allows maintaining binocular vision in the functional gaze range.

This information is for educational purposes. Consult an ophthalmologist for diagnosis and management.