Duane Syndrome is a form of strabismus where the ability of the eye(s) to rotate is abnormal due to “abnormal wiring” in the brain’s control of the eye muscles.   This is a congenital (inborn) problem and there most of the time (70%) there is nothing else wrong.  However, there can be associated abnormalities (Duane Plus); more common problems include anomalies of the cervical spine and other parts of the skeleton (such as the forearm), as well as hearing deficits. 

In terms of eye movement, Duane Syndrome is characterized by an inability to rotate the eye(s) all the way, a subsequent misalignment of the eyes (strabismus) from the abnormal rotations, and an abnormal head position (torticollis) to compensate for the strabismus.  Because the eyes do not move properly they will turn in (or out) and the patient will try to avoid seeing double – double vision is eliminated by turning the head (torticollis).   Typically, torticollis becomes apparent early in life (most babies are able to hold their own head by 3 or 4 months; they quickly learn how to avoid double vision) but many parents do not notice it until the baby starts to walk.

It is generally said that there are three types of Duane Syndrome.   The most common is Duane Type 1 (70%); in these cases, the eye does not fully rotate outwards (towards the ear) and the affected eye turns inwards.   Because the eye cannot move outwards and wants to “look towards the nose” (esotropia) these patients turn their face in the direction that allows them to get rid of the esotropia – if they look towards the nose and turn their face, the esotropia goes away.    For example, someone with Duane Type 1 of the left eye will have an esotropia of their left eye; the left eye wants to look to the right.  If they will turn both eyes to the right, the esotropia goes away; the simplest way keep the eyes straight ahead is to turn the face to the left.   If you straighten their head and have them look straight, you will see the esotropia.  Another finding is that when the eye is attempting to look “towards the ear,” the space between the lids becomes wider; when looking towards the nose, this space becomes narrower – this is because of the innervational abnormalities.  

Duane Type 2 is characterized by abnormality in looking towards the nose.  As a consequence, these folks have the affected eye turning outwards (exotropia).    For example, if the left eye has a Duane Type 2 and is exotropic (looking towards the left ear), the patient will avoid double vision by turning both eyes towards the left.  To turn both eyes to the left but look at something in front of you, you would turn the face to the right; hence, the torticollis to the right for a Type 2 Duane of the left eye.  The abnormal eyelid findings occur here, too (but in the converse).

Duane Type 3 is when both Type 1 and Type 2 occur on the same side.  The eyes are typically straight when looking straight ahead, but to avoid double vision these people must to turn their face because one of the eyes does not move.   Type 3 Duane is rare.

In all three types of Duane Syndrome one or both eyes can be affected.  There can also be “up-shoots” and/or “down-shoots” when the affected eye(s) rotate towards the side.   Finally, over time there is often contracture (“stiffening”) of the muscles around the eye(s), which will change the character of the strabismus.  

The treatment of Duane Syndrome is surgical.  There is no benefit to waiting if torticollis is already present; in fact, waiting can lead to contractures and new surgical problems.  Sometimes more than one surgery is necessary, but this goes for all forms of strabismus.   

Because each patient has their own unique “dose” of rotational abnormality, torticollis, and (possibly) contracture, the surgical planning varies with the individual.  However, there is one common goal: to provide a straight head with straight eyes at the same time.   In general, repair is accomplished by alleviating any contractures that have occurred and by differentially weakening various muscles.  Each case needs to be evaluated and considered separately, and there are numerous accepted methods of surgical management. Surgery can almost always make the problem better, but these patients cannot be cured and there will always be an abnormality in their eye movement.