Problems With Vision
Vision problems that may affect your child:Eye disorders that affect vision can be divided into two
groups, including the following:
- refractive errors
Refractive errors are eye disorders in which the shape of the eye does
not refract the light that enters the eye properly, resulting in blurred
vision.
- non-refractive errors
Non-refractive errors are eye disorders that are not caused by
refractive errors, rather, they are caused by eye diseases.
What are refractive errors?
Refractive errors are seen in almost 20 percent of children. The following
are the most common refractive errors, all of which affect vision:
- myopia or "nearsightedness"
Myopia is the most common refractive error seen in children. Myopia
means that a child can see close up, but has problems with seeing things
far away. It is usually not present at birth, but begins to develop as
the child gets older. It is usually noted in children around the ages of
9 or 10. This might be noted in a child that cannot read the blackboard
from the back of the room, but can see to write and read without a
problem. Other signs and symptoms may include headaches, nausea after
reading, holding books close to one's face, or writing with one's head
very close to the table.
- hyperopia or "farsightedness"
Hyperopia is one type of refractive error in which the child cannot see
things close to him/her, but he/she does not have a problem seeing
things far away. Squinting, eye rubbing, lack of interest in school, and
difficulty in reading may be seen in children with hyperopia. This
condition is uncommon in children.
- astigmatism
Astigmatism is one type of visual condition in which an abnormal
curvature of the cornea occurs, resulting in decreased vision. This can
start in childhood or as an adult and can be easily corrected if it is
causing problems. Some signs and symptoms of astigmatism may include
headache, eye strain, difficulty reading, and fatigue. Depending upon
the severity, eyeglasses or contact lenses may be required.
- amblyopia or "lazy eye"
Amblyopia is one type of visual condition characterized by decreased
vision that occurs in one eye, usually as a result of another problem in
which that eye is not receiving proper visual stimulation. This is
usually preventable if the underlying cause is treated before the child
is 6 years old.
- strabismus or "crossed-eyes"
Strabismus is one of the most common eye problems in children in which
the eyes are misaligned. The eyes (one or both) may turn inward,
outward, turn up, or turn down. At times, more than one of these
conditions are present. Strabismus is also called "wandering eye" or
"crossed-eyes." Children younger than 6 months of age may have a common
form of strabismus that comes and goes. This type of strabismus may be
normal. Strabismus can be a result of poor muscle strength in the eye,
or some children are born with crossed-eyes.
The signs and symptoms of strabismus may include a child squinting
his/her eyes, a child that cannot properly judge distance to pick up
objects, a child that closes one eye to see better, dizziness, or the
child's eyes move inward or outward. Early diagnosis of the underlying
problem is essential in order to prevent vision loss. Treatment of
strabismus may include patching the stronger eye in order to increase
the strength in the weaker eye, eyeglasses, eyedrops, surgery to
straighten the eyes, or eye exercises.
What are non-refractive errors?The following are some causes of non-refractive errors:
- glaucoma
Glaucoma is a condition in which the normal fluid pressure inside the
eyes (intraocular pressure, or IOP) slowly rises as a result of the
fluid aqueous humor - which normally flows in and out of the eye - not
being able to drain properly. Instead, the fluid collects and causes
pressure damage to the optic nerve (a bundle of more than 1 million
nerve fibers that connects the retina with the brain) and loss of vision.
Glaucoma is classified according to the age of onset. Glaucoma that
begins before the child is 3 years old is called infantile or congenital
(present at birth) glaucoma. Glaucoma that occurs in a child is called
childhood glaucoma.
Signs and symptoms of glaucoma may include excessive tearing, light
sensitivity (photophobia), closure of one or both eyes in the light,
cloudy, enlarged cornea, one eye may be larger than the other, and
vision loss. Treatment of glaucoma usually involves surgery, Without
treatment, blindness may occur.
- cataract
A cataract is a clouding or opaque area over the lens of the eye - an
area that is normally transparent. As this thickening occurs, it prevents
light rays from passing through the lens and focusing on the retina
- the light sensitive tissue lining located in the back of the eye.
This clouding is caused when some of the protein which makes up the
lens begins to clump together and interferes with vision. Cataracts
can affect either one eye (unilateral) or both eyes (bilateral). Cataracts
in children are uncommon.
A child may be born with the disease (congenital), or it may develop
later in life (acquired). Possible causes of cataracts include the
following:
- trauma
- diabetes
- poisoning
- steroid use
- other childhood diseases such as rheumatoid arthritis
- complications from other eye diseases, such as glaucoma
The majority of congenital cataracts (those present at birth) are
present in children who also have other eye problems or other health
problems. In approximately 25 percent of children born with congenital
cataracts, the condition is due to a genetic cause such as a metabolic
disorder (caused by an inherited enzyme deficiency) or a chromosome
abnormality (i.e., Down syndrome).
Signs and symptoms of a cataract may include the following:
- white pupil upon flashlight examination
- misaligned eyes
- involuntary rhythmic movements of the eyes back and forth, up
and down, around, or mixed (nystagmus)
- cloudy or blurry vision
- decreased vision
- lights appear too bright and/or present a glare or a surrounding
halo
Treatment of cataracts usually involves surgery.
- retinoblastoma
Retinoblastoma is a rare cancer of the retina. The retina is the innermost
layer of the eye, located at the back of the eye, that receives light
and images necessary for vision. About 200 children in the US are diagnosed
with this type of cancer each year. It mostly occurs in children under
the age of 5; the highest incidence of the disease occurs between infancy
and age 2. Both males and females are affected equally. Retinoblastoma
can occur in either eye, however, in about 25 to 30 percent of the cases,
the tumor is present in both eyes.
Signs and symptoms of retinoblastoma may include:
- leukocoria - a white light reflex that occurs at certain angles
when light is shown into the pupil.
- strabismus (Also called "wandering eye" or "crossed-eyes.")
- a misalignment of the eyes; when one or both eyes do not appear
to be "looking" in the same direction.
- pain or redness around the eye(s).
Treatment for retinoblastoma may include one, or more, of the following:
- surgery
- enucleation (removal of part or all of the eye or eyes involved
with the tumor)
- chemotherapy
- radiation therapy
- phototherapy (uses light to destroy the blood vessels that supply
the tumor)
- cryotherapy (uses a freezing process to destroy the tumor)
Additional treatment may include one or more of the following:
- fitting and training for a prosthesis
- blind or decreased vision adaptation training
- supportive care (for the side effects of treatment)
- antibiotics (to prevent/treat infection)
Click here to view the
Online Resources page of this Web.
|
