What is Duane syndrome?
Duane syndrome is a disorder of eye movement. This condition prevents outward movement of the eye (toward the ear), and in some cases may also limit inward eye movement (toward the nose). As the eye moves inward, the eyelids partially close and the eyeball pulls back (retracts) into its socket. Usually only one eye is affected. Some people with Duane syndrome develop amblyopia (“lazy eye”), a condition that causes vision loss in the affected eye.
There are three forms of Duane syndrome, designated types 1, 2, and 3. The types vary in which eye movements are most severely restricted (inward, outward, or both). All three types are characterized by retraction of the eyeball as the eye moves inward and are inherited in an autosomal dominant fashion.
How common is Duane syndrome?
Duane syndrome is not common. It has been seen in diverse ethnic groups. The frequency of DS in the general population of individuals with eye movement disorders (strabismus) is approximately one to 5 percent. Most individuals are diagnosed by the age of 10 years. The female to male ratio of individuals with DS is approximately 60:40, showing a slightly higher preponderance of female patients. Please discuss with your doctor for further information.
What are the symptoms of Duane syndrome?
Duane syndrome (DS) is present at birth and is characterized by limitation of horizontal eye movement (a limited ability to move the eye inward toward the nose (adduction), outward toward the ear (abduction), or in both directions). In addition, during adduction, the eyeball pulls in and the eye opening (palpebral fissure) narrows. In some cases, when the eye attempts to look inward, it moves upward or downward. Duane syndrome has 3 sub-types which vary depending on which type of eye movement is most restricted.
- In Duane syndrome type 1, abduction is limited, but adduction is normal or close to normal. The eye opening narrows and the eyeball retracts into the orbit during adduction, and the reverse occurs during abduction.
- In Duane syndrome type 2, adduction is limited, and abduction is normal or only slightly limited.
- In Duane syndrome type 3, both adduction and abduction are limited. The eyeball retracts during adduction in types 2 and 3.
Each of these three types has been further classified into three subgroups designated A, B, and C to describe the eyes when looking straight.
The majority of people with Duane syndrome do not have any other health problems. However, in rare cases, patients with the disorder also have complex conditions such as:
- Skeletal malformations
- Kidney problems
- Hearing loss
- Nervous system disorders
- Goldenhar syndrome, a birth defect involving deformities on one side of the face
- Holt-Oram syndrome, also known as hand-heart syndrome, an inherited disorder that causes malformations in the heart and upper limbs
- Morning Glory syndrome, also known as optic nerve coloboma, a birth defect that causes a separation in the optic nerve and severe loss of vision
- Okihiro syndrome, a rare, inherited disorder combining Duane syndrome with hearing loss and arm malformation
- Wildervanck syndrome, an inherited disorder—almost always affecting girls—that involves Duane syndrome, hearing loss and fused neck vertebrae
Although Duane syndrome is congenital (present at birth), it may take as long as several years for it to become noticeable: very young children cannot vocalize the fact that they are having trouble with their vision, while older children may have learned to compensate very well for their visual difficulties. In both cases, the symptoms children show can be quite subtle. Most people with Duane syndrome are diagnosed by age 10.
When symptoms are noticeable, they usually include:
- Holding the head in an abnormal posture, turned to the right or left
- Crossing or misalignment of the eyes
- Closing one eye to see better
Older children may be able to describe the problems they are experiencing, such as:
- Double vision
- Neck pain
- Difficulty seeing things on the side of the affected eye
Since these symptoms can also be caused by other eye disorders, it’s important to obtain an evaluation from a qualified eye doctor as soon as possible.
There may be some symptoms not listed above. If you have any concerns about a symptom, please consult your doctor.
When should I see my doctor?
If you or your loved one has any signs or symptoms listed above or you have any questions, please consult with your doctor. Everyone’s body acts differently. It is always best to discuss with your doctor what is best for your situation.
What causes Duane syndrome?
Given the evidence that Duane syndrome (DS) results from an absence of the abducens nerve (cranial nerve VI) and aberrant innervation, and that it is associated with other anomalies in some cases, it is thought to result from a disturbance of normal embryonic development by either a genetic or an environmental factor at the time when the cranial nerves and ocular muscles are developing (between the third and sixth week of pregnancy). Genetic studies of two large families with DS inherited autosomal dominantly (without associated abnormalities) established that mutations in the CHN1 gene were found to be the cause in these and several other families.
Duane-radial ray syndrome (DRRS), inherited in an autosomal dominant manner, has been shown to be caused by mutations in the SALL4 gene. However, no SALL4 gene mutations were found in 25 sporadic cases of isolated DS (occurring in one individual in a family with no additional abnormalities).
DS can also be found as part of another complex autosomal recessive disorder (that can include deafness, facial weakness, vascular malformations and leaning difficulties) due to mutations in the HOXA1 gene. In addition, chromosome studies of individuals with DS and other abnormalities have, in rare cases, shown abnormalities that suggest other locations for genes responsible for causing DS.
What increases my risk for Duane syndrome?
The majority of cases of Duane syndrome are sporadic (occurring in individuals with no history of the condition in the family). About 10% of affected individuals appear to have other affected family members. Both autosomal dominant (most commonly) and autosomal recessive forms of Duane syndrome have been documented. In some families with dominant Duane syndrome, it has appeared to “skip a generation” (showing reduced penetrance) and it has also been shown to range in severity within the same family (showing variable expressivity). Most familial cases are not associated with other anomalies. Given the large percentage of sporadic cases, it seems likely that both genetic and environmental factors play a role in the development of Duane syndrome amongst affected individuals. Please consult with your doctor for further information.
Diagnosis & treatment
The information provided is not a substitute for any medical advice. ALWAYS consult with your doctor for more information.
How is Duane syndrome diagnosed?
There is currently no test available that can detect a genetic marker for the disorder, except for the CHN1 genetic test when Duane syndrome affects more than one generation in a family.
When the presence of DS is suspected, a thorough ocular (eye) examination is required, with special attention to the presence of other ocular or systemic malformations. Measurements of the ocular misalignment, ocular range of motion, head turn, globe (eyeball) retraction, palpebral fissure (eye opening) size, upshoots and downshoots and visual acuity are indicated. In addition, an examination of the cervical (neck) and thoracic (chest) spine, palate (roof of mouth), vertebrae, hands, and a hearing test is recommended to rule out disorders associated with DS.
How is Duane syndrome treated?
The treatment of Duane syndrome may involve surgery. The goal of surgery is to eliminate or improve head turn, eliminate or reduce significant misalignment of the eyes, reduce severe retraction (when they eyeball pulls into the socket as the eye moves toward the nose), and improve upshoots and downshoots (when the eye deviates upward or downward with certain eye movements). No specific surgical technique has been completely successful in eliminating the abnormal eye movements. However, some procedures, used either alone or in combination, may be successful in improving or eliminating head turns and misalignment of the eyes. The choice of procedure varies among affected individuals. The success rate for surgery in eliminating an abnormal head position is estimated to be 79-100%.
The management of Duane syndrome without surgery may include:
- Special seating in school to accommodate a child’s head turn
- Special rear-view mirrors to help during driving
- A prism placed on the individual’s glasses to correct for the face turn (though this is not commonly used)
- Vision therapy to treat secondary convergence insufficiency (inability of the eyes to turn towards each other or sustain this position)
Lifestyle changes & home remedies
What are some lifestyle changes or home remedies that can help me manage Duane syndrome?
If you have any questions, please consult with your doctor to better understand the best solution for you.
Hello Health Group does not provide medical advice, diagnosis or treatment.
Hello Health Group does not provide medical advice, diagnosis or treatment.