Duction

A duction is an eye movement involving only one eye.[1] There are generally six possible movements depending upon the eye's axis of rotation:

  1. Abduction refers to the outward movement of an eye.
  2. Adduction refers to the inward movement of an eye
  3. Supraduction / sursumduction / elevation
  4. Infraduction / deosumduction / depression
  5. Incycloduction / intorsion
  6. Excycloduction / extorsion

Forced duction test

The forced duction test is performed in order to determine whether the absence of movement of the eye is due to a neurological disorder or a mechanical restriction.[2]

The anesthetized conjunctiva is grasped with forceps and an attempt is made to move the eyeball in the direction where the movement is restricted. If a mechanical restriction is present, it will not be possible to induce a passive movement of the eyeball.[3]

Notes
  1. Kanski, JJ. Clinical Ophthalmology: A Systematic Approach. Boston:Butterworth-Heinemann;1989.
  2. Forced duction - definition from Biology-Online.org
  3. Kunimoto D, Kanitkar K & Makar M. The Wills Eye Manual. Office and Emergency Room Diagnosis and Treatment of Eye Disease. Fourth Edition. Lippincott Williams & Wilkins; 2004
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See also
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