Nystagmus – A Little Known Yet
Surprisingly Common Eye
Condition.
Nystagmus
is a type of uncontrolled eye movement affecting
approximately one in every 2,000 individuals, it is
characterized by alternating smooth eye movement in one
direction and saccadic (abrupt, short) movement in the
other direction. Movement is usually from side to side
but, sometimes movement can be up and down or even
circular. Nystagmus is not painful and does not lead to
progressive loss of vision
Types of
Nystagmus
There are
more than 40 different types of nystagmus but they are
usually classified into two basic categories: 1.
Nystagmus present from early in life, is known as
early onset
nystagmus, or
congenital
nystagmus, it often accompanies vision loss acquired
at birth or soon after and may be one of the first signs
that a child has a loss of vision.
2.
Nystagmus which develops later in life is called Acquired
Nystagmus.
Causes of
Nystagmus
1. Early
onset nystagmus: Pediatric Nystagmus may be caused by a
problem with the eyes or the visual pathways leading from
the brain to the eyes. This type of nystagmus is usually
first observed between 6 weeks and 8 weeks of age and can
be associated with albinism, optic nerve problems or
retina problems. There is likely to be a genetic factor
and in fact doctors have recently announced a
breakthrough in the discovery of a gene associated with
nystagmus which holds great promise for future
treatments.
Many
patients do not have any eye, brain or other health
problem and in these cases the condition is known as
congenital
idiopathic nystagmus (meaning that the nystagmus
starts early and the cause is unknown). Nystagmus
associated with albinism has characteristics similar to
idiopathic nystagmus but usually is absent until after
age 2 months. Nystagmus can also be found in children
with Down’s syndrome.
2.
Acquired nystagmus: Nystagmus can be acquired later in
life due to neurological dysfunction such as a head
injury, multiple sclerosis or brain tumors. Nystagmus can
also be caused by lesions in the cerebellum, the area of
the brainstem where the vestibular cranial nerve arises
or further along the vestibular pathways.
Signs and Symptoms of
Nystagmus
Nystagmus
is associated with reduced vision, constant movement of
the eyes which gets worse with tiredness or stress,
fluctuations in visual acuity, sometimes with head
nodding and often the head is carried at an angle and the
eyes are kept to one side (this slows the movement,
providing a null
point and allows for better vision). Patients with
nystagmus frequently have other vision problems such as
astigmatism that require prescription eyeglasses and
strabismus. Impairment to binocular vision is common with
early onset nystagmus and depth perception is indirectly
impaired in many patients.
The
presence of a pale optic disk, or a history of
progressive visual loss, should suggest that the
nystagmus is acquired and possibly due to a neoplasm
involving the visual
system.
Risk Factors
The
following factors increase your chance of developing
nystagmus: a family member with nystagmus, albinism, eye
disorders such as optic nerve degeneration, severe
astigmatism, or near sightedness, diseases of the body
such as Menieres disease, multiple sclerosis, stroke,
head injuries, use of medications, such as lithium or
anti seizure medications, alcohol or drug use and
infection of the inner ear.
Treatment for
Nystagmus
At present
there is no cure for nystagmus however, for the first
time there are an increased number of researchers
working on the condition and genetic research in
particular offers new hope.
Contact
Lenses Contact lenses have been shown to aid some
nystagmus patients probably because of the actual contact
with the eye leading to better control of the horizontal
nystagmus movement.
Prisms can
be used to help the eyes converge thus reducing the
nystagmus.
Simple
tests like visual acuity can be misleading as the vision
may decrease if the patient is under stress or has latent
nystagmus which causes an increase in nystagmus in both
eyes when one eye is covered.
Biofeedback
which teaches the patient to control eye movements to
some extent by the use of visual and audio effects has
been reported to be beneficial by some people.
Surgery,
in particular tetonomy (cutting the eye muscles and
reattaching them) has been quite successfully used in
the United
States. Botox,
Baclofen and recently Mamentine and Gabapentin are drugs
which are being tried out. There have been reports of
good success with auricular
acupuncture.
Living with Nystagmus
Nystagmus
can affect nearly every aspect of life, including how a
patient relates to other people, educational and work
opportunities and self image.
Most
people who have had nystagmus all their lives are not
effected by the constantly moving image as their brain
has adapted to the movement of the eyes, but those with
acquired nystagmus can not adjust as well and may suffer
from dizziness and vertigo.
Depth
perception is usually reduced considerably, this can
cause problems with balance and a perceived clumsiness.
Except for
certain parts of the USA where optical devices are
accepted, people with nystagmus can not get a driving
licence so that they have to rely on public transport
which can be a problem in itself in unfamiliar
places.
Socially,
because it is difficult for someone with nystagmus to
maintain eye contact, it can be a problem maintaining
self confidence. However there are many people with the
condition who live an extremely successful and fruitful
existence, adapting easily to their condition and
building perfectly normal lives.
For
children with nystagmus it is important that their
teachers and classmates are advised as to how the
condition affects them so as to prevent problems caused
by misunderstandings. For example, children with
nystagmus may read slowly because of the extra time
needed to scan printed material. This should not be taken
as a sign of poor reading ability. Students or school
children with nystagmus may need extra time to study and
when sitting exams. Many students with nystagmus use
computers, as they can position screens to suit their own
needs and adjust brightness, character size, and so on.
Nystagmus Network
Support
The two
main organizations with informative websites on nystagmus
are:
United
Kingdom Nystagmus
UK
United
States
Nystagmus
USA
There are also organizations in
Italy
,
Germany
,
India
and
Japan
.
For innovative treatment products
visit:
www.life-wave-patches.com
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