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What is Nystagmus?
Nystagmus is an unintentional jittery movement of the eyes. Nystagmus
usually involves both eyes and is often exaggerated by looking in a
particular direction.
What Causes Nystagmus?
Many
conditions are associated with nystagmus. Sometimes, the brainās
control of eye movements is poor, resulting in an inability to look
steadily at an object. Some forms of nystagmus are associated with
reduced vision such as occurs in albinos, extreme near or farsighted
people, or in those with scars in the retina or optic nerve. Rarely,
nystagmus can occur as a result of brain tumors or in serious
neurologic disorders. Nystagmus can be found in families as an
isolated problem, not associated with other conditions.
What should be done about Nystagmus?
A
thorough evaluation by an ophthalmologist and perhaps other medical
specialists is important. The cause can usually be determined.
Important clues relate to age of onset, family history, general health
of the patient, or the use of certain medications. Your
ophthalmologist may examine the pattern of the nystagmus, its speed
and direction and look for other eye problems such as a droopy lid,
cataract, or an abnormality of the retina or optic nerves. Blood
tests or special x-rays may be useful in determining the cause.
Can Nystagmus Be cured?
Sometimes, removal of the cause may cure nystagmus. Often, however
nystagmus is permanent. The reduced vision may be improved with
glasses and low vision aids. If the eyes are more stable while
looking in a certain direction glasses with prisms or eye muscle
surgery may improve the head position and allow better vision.
Medication, biofeedback and eye exercises have rarely helped control
nystagmus.
What are the most common forms of nystagmus?
Motor nystagmus tends to
begin between six weeks and three months of age. Other family members
may have similar unusual eye movements. The motion is usually
horizontal. Often focusing up sloe or looking in an odd direction
reduces the nystagmus intensity and improves the vision. Fortunately,
patients DO NOT see the world moving as their eyes move. Vision may
be reduced at distance but is almost normal up close. There are
usually no limits to the educational potential of one who has motor
nystagmus.
Sensory nystagmus is
associated with reduced vision of any cause. Sensory nystagmus
usually begins at 6 to 8 weeks of age. The eyes appear to rove,
sometimes slowly and sometimes quickly. Very often the eyes will also
rotate upward and the eyelids may flicker as well. As a baby becomes
older, he may poke at his eyes or wave his hands in front of them.
Sometimes the cause is treatable as in babies who are born with
cataracts. Other conditions which can lead to sensory nystagmus may
not be treatable. Nevertheless, understanding the underlying cause is
of great importance to predicting how the baby will so in the future.
What are other causes of nystagmus?
Medications or drugs can cause nystagmus. Rarely, this nystagmus can
be associated with double vision and is often worse looking to the
side. Causes include excessive drinking of alcohol, or use of
medications such as those given for seizure control. Often the
nystagmus will improve if the medication is stopped.
Voluntary nystagmus can be
created by some people much in the same way as ear wiggling. Fine
rapid, horizontal movements can be produced and sustained for a short
period of time. Often this is done to gain attention.
Disease-induced nystagmus is
less common. It is often associated with neurologic signs and
symptoms which indicate the seriousness of the problem.
Summary
If
nystagmus is present, a full eye examination by an ophthalmologist is
needed. Underlying causes which determine the effect on the patientās
life and vision vary greatly.
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