Gaze nystagmus is a medical condition that refers to an inability to control fine movements of the eyes. The disorder can develop in many different ways, and it can affect one or both eyes. A person may have difficulties with horizontal, vertical, or rotational movement of the eyes, or be unable to affix a gaze in a particular direction. Temporary cases of gaze nystagmus are common with excessive alcohol use and some medications, while more permanent conditions manifest with congenital brain defects or acquired head injuries. Treatment options can include corrective contact lenses, botulinum toxin injections, and minimally-invasive surgery.
Congenital gaze nystagmus is a fairly common condition that is usually mild enough to go undetected for several years. It is possible, however, for an infant to have obvious problems moving the eyes horizontally, vertically, or in a rotating pattern. Gaze nystagmus commonly presents as an uncontrollable tendency for one or both eyes to shift away from a focal object. A baby's eyes might jerk back to a center position when trying to look upward or drift to one side when trying to look straight ahead.
When gaze nystagmus is present early in life, the cause is usually due to a developmental problem of the retina, optic nerve, or cerebellum. Traumatic injury to the brain stem before or during both may also cause symptoms. There is some evidence that gaze nystagmus may have a genetic, inheritable component as well. Other vision problems such as glaucoma, cataracts, or astigmatism can worsen vision problems in infants and young children. It is common for a child to tilt his or her head in a particular direction most of the time as an automatic response to seeing difficulties.
Acquired gaze nystagmus can develop at any age, though it is more common in children than adults. Major head injuries or lingering congenital brain defects can be responsible for changes in eye movement. Some people who consume dangerous levels of alcohol or have adverse responses to anti-seizure medications, such as phenobarbital or phenytoin, can develop temporary symptoms. Eye spasms and sudden movements may be so subtle that vision is not affected severely enough to cause major blurring, spotty sight, or double vision.
An optometry expert can diagnose gaze nystagmus by evaluating symptoms and carefully peering into the eyes with a specialized microscope. X-rays and computerized tomography scans may be taken to look for signs of brain abnormalities. After confirming the underlying cause, the doctor can discuss different treatments.
Symptoms related to medications or alcohol can usually be reversed by abstaining from the aggravating substances. Prescription contact lenses and laser surgery to correct astigmatisms and other problems are important in treating some forms of nystagmus. Other surgical procedures may be needed in cases where the cerebellum, optic nerve, or retina are obviously deformed. Periodic injections of botulinum toxin type A also can decrease the severity of eye movements in patients who are not good candidates for surgery.