Eye retraction syndrome, also called Duane syndrome or Duane retraction syndrome, a rare congenital disease, affects the muscle of the eyes. Around 90 percent of people with the disease have no family history of it, the American Academy of Pediatric Ophthalmology and Strabismus reports. Three subtypes of the disease exist, with Type 1 occurring in around 78 percent of patients, the AAPOS adds.
Characteristics
Eye retraction syndrome is a type of strabismus, or misalignment of the eyes. In 80 percent of cases, only one eye is affected, the National Human Genome Research Institute states. If the person has a family history of the disease, both eyes are more likely to be affected. The left eye is more often affected than the right. Around 60 percent of people with eye retraction syndrome are girls. The disease normally manifests itself before age 10.
Cause
Abnormal fetal development around the sixth week of pregnancy causes eye retraction syndrome, according to the AAPOS. The parts of the brainstem that control eye muscle movement fail to develop properly. Cranial nerve VI, the abducens nerve, appears to be missing in individuals with the disease as a result. Problems with cranial nerve III may also be present.
Symptoms
Eye retraction syndrome causes difficulty moving the lateral rectus or medial rectus muscle. Symptoms include difficulty turning the eye inward, toward the nose, or outward, toward the ear. The eye may appear to retract when the person looks toward his nose and may appear to move outward when he looks toward his ear. The affected eye may appear smaller than the normal eye due to a narrowed eyelid. Vision in the affected eye may be decreased, and the eye may point in different directions. The person may keep his head turned in a certain position to keep the eye straight. The eye may deviate upward or downward with certain eye movements.
Treatment
Treatment may involve surgery to straighten the eye, improve vision or help correct an abnormal head position. Most people with eye retraction syndrome don't require surgery, however, according to the AAPOS. The affected nerve can't be repaired or improved during surgery.
Considerations
In 70 percent of cases, eye retraction syndrome is the only abnormality present, but eye retraction syndrome can occur in conjunction with other congenital anomalies such as hearing loss, spinal and vertebral abnormalities, nervous system abnormalities or a number of syndromes, according to AAPOS and Engle Laboratory. Eye retraction syndrome may also occur more frequently in people who have been exposed to thalidomide. Children diagnosed with eye retraction syndrome should be checked for other anomalies. Treatments are aimed at reducing symptoms but will not cure the underlying disease.
