What Is Duane Syndrome? About this Rare Disease

By Allie Johnson; reviewed by Valerie Kattouf, OD, FAAO

What is Duane syndrome?

Duane syndrome (DS) is a type of eye misalignment (strabismus) that affects the movement of one or both of a baby’s eyes from the time they are born. About 80% to 90% of DS cases involve only one eye — more often the left eye, but sometimes the right. In rarer cases, both eyes may be affected.

While there is no cure for Duane syndrome, an eye doctor can offer diagnosis and treatment options ranging from eyeglasses to surgery. Many DS patients don’t need any treatment at all.

What causes Duane retraction syndrome?

Duane syndrome may be caused by a genetic or environmental factor that affects development early in pregnancy. In DS, there is a "miswiring" of the nerves controlling the middle (medial) and outside (lateral) eye muscles. About 10% of DS patients have other family members with the condition, but most cases have no known cause.

There are several different types of Duane syndrome, classified depending on how a patient’s eye movement is affected.

Different types of Duane syndrome

There are three main types of Duane syndrome:

Duane syndrome type 1 – A child with type 1 Duane syndrome has limited outward movement of the eye (abduction, or looking out toward the ear) and experiences little to no effect on the inward movement of the eye (adduction, or looking in toward the nose). These patients may present with an inward eye turn (esotropia). Type 1 DS is the most common, making up 78% of cases.
Duane syndrome type 2 – A person with type 2 DS has limited inward eye movement (adduction) and minimal effect on the outward eye movement (abduction). An eye turn outward (exotropia) is common.
Duane syndrome type 3 – A person with type 3 DS has limitations on both their inward (adduction) and outward (abduction) eye movements. An outward eye turn (exotropia) is common.

SEE RELATED: Oscillopsia (Shaky Vision)

Signs and symptoms of Duane syndrome

Signs and symptoms of Duane syndrome vary based on the patient, the type of DS and which eye (or eyes) are affected.

Here are eye issues that may occur on their own but also can be signs of Duane syndrome:

Droopy eyelid – Duane syndrome can cause congenital ptosis, a droopy eyelid present from birth.
Eye movements – A DS patient may have difficulty moving an eye from side to side and may move their eye upward or downward suddenly.
Eyes of different sizes – If only one eye is affected by DS, that eye may look smaller than the other due to eye (or eyelid) narrowing.
Amblyopia – About one in 10 DS patients may have amblyopia (lazy eye) and lower visual acuity in the affected eye.
Misaligned eyes – DS patients may also have hypertropia, a type of strabismus in which one eye drifts upward.
Retracted eye – Some patients may have an eyeball that sits further back in the socket than it should.
Unusual head position – Some DS patients may move or hold their head a certain way to try to make up for vision problems.

In about seven of 10 cases, a DS patient has no health or eye problems other than Duane syndrome. DS can also be linked to problems with other body systems, including the ears, kidneys and urinary tract, nervous system, and skeletal system.

In extremely rare cases, Duane syndrome can occur alongside other rare conditions, including Goldenhar syndrome, Holt-Oram syndrome and Wildervanck syndrome. The National Organization for Rare Disorders offers more information about these and other ailments.

Diagnosis, treatment and standard therapies

An eye doctor will do a comprehensive eye exam and diagnose Duane syndrome based on their clinical findings. They will look at:

The position of the child’s head
The child’s eye movements
The alignment of the child’s eyes when viewing in all directions

The doctor will make the diagnosis of Duane syndrome if two very specific findings are present in their exam:

Narrowing of the affected eye when looking inward – This means that as the affected eye looks inward toward the nose (adduction), the eyelids come closer together and less of the eye can be seen
Sinking of the affected eye into the eye socket when looking inward – This means that as the eye looks inward (adduction), it moves deeper into the socket (this is called globe retraction)

These two characteristics are found in all three types of DS and must be present in order to diagnose a patient with Duane syndrome.

A patient may also need to visit a family doctor or specialist for a physical exam and hearing test to check for any related hearing or general health problems. In some cases, a doctor may order genetic testing.

SEE RELATED: Sunken eyes (enophthalmos)

Duane syndrome treatment

Treatment for Duane syndrome will depend on a child’s individual case and symptoms. Typically, the goals of DS treatment are to:

Help the patient hold their head in a normal and comfortable head position
Improve eye alignment
Treat double vision (diplopia)

Duane syndrome treatment options may include:

Vision correction – An eye doctor may prescribe glasses or contact lenses to correct refractive errors such as farsightedness (hyperopia), nearsightedness (myopia) and/or astigmatism. Clear and single vision is the goal and starting point of any treatment plan.
Prism glasses – Prism glasses may help the patient hold their head in a more natural position and eliminate any double vision the patient may struggle with.
Monitoring – Many DS patients only need to have their condition monitored without undergoing any treatment. The patient and parents should be educated about DS so they quickly notice any changes in the child’s condition.
Surgery – In rare cases, a patient may need surgery to treat their eye turn.

With treatment from an eye doctor, patients with Duane syndrome may achieve eye alignment and visual comfort.

The importance of regular eye exams

Babies and children should get their eyes checked regularly. If your baby is showing any signs or symptoms of Duane syndrome, make an appointment with an eye doctor right away. As some signs of DS may also point to other eye problems, it's best to get a prompt eye exam, diagnosis and treatment plan for your child.

READ MORE about rare eye diseases.