Experts
Say Have Regular Eye Exams As You Age
June Is Vision
Research Month
Even those with nearly
perfect eyesight throughout their lifetime will most likely
encounter a vision problem as they age.
For some, it is a
relatively minor problem, such as presbyopia - the loss of the
ability to see small print and objects close up - which typically
occurs in middle age. Remedies are straightforward, such as
reading glasses, bifocals, or contact lenses fit in a "monovision"
fashion so one eye is used mainly for distance vision, the other
for near objects.
More serious problems
are what eye-care experts call the "vision-robbers" that become
more common with age: cataracts, glaucoma, and macular degeneration.
Due to the aging population,
more Americans than ever are facing the threat of blindness
due to these age-related diseases, according to a 2002 report
by the National Eye Institute (NEI), in partnership
with Prevent Blindness America.
More than 1 million
Americans aged 40 and over are currently blind and another 2.4
million are visually impaired, the report says.
Because macular degeneration,
glaucoma, and cataracts are some of the leading causes of blindness,
eye-care experts are using June - designated Vision Research
Month - to heighten awareness of these diseases.
Regular
Eye Exams Counter Problems
While family history
and environmental factors play a role in who does and does not
eventually encounter a problem, there are preventive measures
that can help reduce risk, or at least ensure the diseases are
detected in early, more treatable stages.
"The best thing you
can do is have regular eye exams by an eye-care professional,"
says Dr. Tim Wingert, an optometrist and acting director of
the American Optometric Association's Clinical Care Group.
For those aged 40
to 64, eye-care experts recommend an exam every two years; after
65, an annual exam is recommended.
Those at higher risk
or with early stages of vision disease may be advised to get
more frequent exams, Dr. Wingert says.
Keeping yourself in
the best possible health, and taking measures such as wearing
sunglasses, can also help, eye experts say.
Cataracts
Cloud the Eye
Of all the age-related
vision diseases, cataracts - the clouding of the lens of the
eye - are the least serious, mostly because the surgery to correct
the problem has become so precise, experts say.
"Cataracts are not
a threat the way others are," says Dr. Lylas Mogk, an ophthalmologist
and director of the Visual Rehabilitation and Research Center
of the Henry Ford Health System in Detroit.
More than 1 million
cataract operations are performed annually in the US, according
to Research to Prevent Blindness, a New York City-based organization
that funds eye research.
Cataracts affect nearly
20.5 million Americans aged 65 and older, according to the NEI.
"You remove the lens
and replace it [with an artificial lens]," Dr. Mogk says. "The
skill level of the surgeon has to be terrific. The incision
is minute, you don't even need to put a stitch in."
Glaucoma
Elevates Pressure in the Eye
Glaucoma, a serious
disease, affects about 2.2 million Americans who know they have
it and another 2 million who do not yet know, according to estimates
from the NEI.
Glaucoma can cause
the fluid pressure within the eye to build up, and eventually
it can damage the optic nerve. Eye-care experts test for glaucoma
using a variety of methods, including the "puff test," in which
a puff of air is directed toward the eye, to determine if intraocular
pressures are normal.
Family history and
racial background can drive up the risk of glaucoma, Wingert
says, with African Americans at greater risk than other
groups of people, although researchers are not sure why.
If treated early,
the outlook for the glaucoma patients is good, Dr. Mogk says.
"The vast majority of people with glaucoma can be treated and
avoid having vision loss," he says.
Medication in drop
form is the usual treatment, he says. Another option is surgery
to create a tiny hole to drain excess fluid.
Macular
Degeneration Affects Fine Vision
The biggest threat
to vision is macular degeneration, Dr. Mogk says. More than
1.6 million Americans over age 60 have advanced macular degeneration,
according to the NEI.
In this condition,
the macula, a tiny area of the retina that allows clear central
vision - which is crucial to such tasks as driving a car or
reading - deteriorates.
There are two types
of macular degeneration, known as wet and dry, Dr. Mogk says,
adding, "Everyone starts as dry."
In the dry form, tiny
white spots known as drusen develop in the eye. About 15 percent
of those affected go on to develop the wet form, in which a
network of blood vessels develops in the eye, leaks and gradually
obstructs vision.
For the wet form is
responsible for 10 percent of disease cases, but accounts for
90 percent of all severe vision loss caused by either type of
AMD.
Wet AMD occurs when
new blood vessels behind the retina start to grow beneath the
retina where they leak fluid and blood and can create a large
blind spot in the center of the visual field. If this happens,
there is a marked disturbance of vision in a short period of
time.
Treatment options
include laser surgery to cauterize the blood vessels or photodynamic
therapy, in which a drug activated by light destroys the abnormal
vessels, Dr. Mogk says.
Nutritional supplements
may help macular degeneration patients at risk of developing
advanced stages of the disease, a study reported in 2001 suggests.
In the study, published in the Archives of Ophthalmology,
those who took a combination of vitamin C, vitamin E, beta-carotene,
and zinc had less vision loss caused by the condition.
Patients should ask
their eye doctor about whether the regimen might work for them
and about the exact dose.
Always consult your physician for more information.
What
Are the Different Types of Cataracts?
The American Academy
of Ophthalmology describes the different types of cataracts
according to the cataract location on the eye lens, including:
nuclear cataract
This is the most common type of cataract, and the most common
type associated with aging. Nuclear cataracts develop in the
center of the lens and can induce myopia, or nearsightedness
- a temporary improvement in reading vision which is sometimes
referred to as "second sight." Unfortunately, "second sight"
disappears as the cataract grows.
cortical cataract
This type of cataract initially develops as wedge-shaped spokes
in the cortex of the lens, with the spokes extending from the
outside of the lens to the center. When these spokes reach the
center of the lens they interfere with the transmission of light
and cause glare and loss of contrast.
This type of cataract
is frequently developed in persons with diabetes, and while
it usually develops slowly, it may impair both distance and
near vision so significantly that surgery is often suggested
at an early stage.
subcapsular
cataract
A subcapsular cataract usually starts as a small opacity under
the capsule, at the back of the lens. This type of cataract
develops slowly and significant symptoms may not occur until
the cataract is well developed. A subcapsular cataract is often
found in persons with diabetes, myopia, retinitis pigmentosa,
and in those taking steroids.
Always consult your physician for more information.
What
Are the Different Types of Glaucoma?
open-angle
glaucoma
With this most common type of glaucoma, the fluid that normally
flows through the pupil into the anterior chamber of the eye
cannot get through the filtration area to the drainage canals,
causing a build-up of pressure in the eye. Nearly 2.2 million
Americans have been diagnosed with glaucoma, and almost 2 million
do not know they have the disease.
low-tension
or normal-tension glaucoma
While normal intraocular pressure ranges between 12 to 21 mm
Hg, an individual may have glaucoma even if the pressure is
within this range. This type of glaucoma presents optic nerve
damage and narrowed side vision.
angle-closure glaucoma
In angle-closure glaucoma, the fluid at the front of
the eye cannot reach the angle and leave the eye because the
angle becomes blocked by part of the iris. This results in a
sudden increase in pressure and is generally a medical emergency,
requiring immediate treatment to improve the flow of fluid.
childhood glaucoma
Childhood glaucoma is a rare form of glaucoma that
often develops in infancy, early childhood, or adolescence.
Prompt medical treatment is important in preventing blindness.
congenital glaucoma
Congenital glaucoma, a type of childhood glaucoma,
occurs in children born with defects in the angle of the eye
that slow the normal drainage of fluid. Prompt medical treatment
is important in preventing blindness.
primary glaucoma
Both open-angle and angle-closure glaucoma can be classified
as primary or secondary. Primary glaucoma cannot be contributed
to any known cause or risk factor.
secondary
glaucoma
Both open-angle and angle-closure glaucoma can be classified
as primary or secondary. Secondary glaucoma develops as a complication
of another medical condition or injury. In rare cases, secondary
glaucoma is a complication following another type of eye surgery.
Always consult your
physician for more information.
What
Is Age-Related Macular Degeneration (AMD)?
Age-related macular
degeneration (AMD) is a disease that affects an individual's
central vision. AMD is the most common cause of severe vision
loss among people over 60. Because only the center of vision
is affected, people rarely go blind from this disease. However,
AMD can make it difficult of read, drive, or perform other daily
activities that require fine, central vision.
AMD occurs when the
macula, which is located in the center of the retina and provides
sight in the center of the field of vision, begins to degenerate.
With less of the macula working, central vision - which is necessary
for driving, reading, recognizing faces, and performing close-up
work - begins to deteriorate.
Always consult your
physician for more information.
|
June 2003
Experts
Say Have Regular Eye Exams As You Age
Regular
Eye Exams Counter Problems
Cataracts
Cloud the Eye
Glaucoma
Elevates Pressure in the Eye
Macular
Degeneration Affects Fine Vision
What
Are the Different Types of Cataracts?
What
Are the Different Types of Glaucoma?
What
Is Age-Related Macular Degeneration (AMD)?
National
Headache Awareness Week -- June 1-7
How
a Migraine Happens
Online
Resources
National
Headache Awareness Week --
June 1-7
Not long ago, migraine
sufferers had no choice but to head for darkened bedrooms to
wait out the pain.
Or they could down
powerful painkillers that could lead to ferocious "rebound"
headaches and, ultimately, addiction.
But dramatic breakthroughs in recent years have led to better
understanding of migraines.
These headaches can
produce intense, throbbing pain, typically on one side of the
head, and are sometimes accompanied by nausea and sensitivity
to light and sound.
New treatments have
vastly improved the the lives of those who experience migraines.
That's a message specialists
are hoping to convey during National Headache Awareness
Week, June 1-7.
Dr. Lisa K. Mannix, a Cincinnati neurologist who specializes
in treating headaches, says migraine care has been "revolutionized"
in the past decade.
"I often joke that
I didn't have to practice in the dark ages, which makes some
of my [older] colleagues a little jealous," says Dr. Mannix.
"I know I have treatments that are very effective for
the majority of patients."
A huge advance in the treatment of migraines came in 1993 when
the first triptan medication came to the market. Sumitriptan,
also known as Imitrex, mimics the neurotransmitter serotonin,
whose supply drops off during migraines.
Sumitriptan causes
blood vessels to constrict, which soothes the inflammation of
nerve endings in the brain and eases pain.
Over the past decade,
six other triptans have become available. Like other classes
of drugs such as antidepressants and antibiotics, different
triptans might work for some people, but not others.
Experts say other
drugs appear to help prevent migraines or reduce their frequency
and severity. These include Botox, better known for its ability
to smooth away facial wrinkles, as well as beta blockers and
calcium-channel blockers, both used to treat high blood pressure
and coronary artery disease.
Antidepressants that
affect serotonin levels may help prevent migraines. And
anti-seizure medications, used to treat epilepsy and bipolar
disorders, also have shown promise for their ability to prevent
migraines.
Dr. Seymour Diamond,
executive chairman of the National Headache Foundation,
says he knows of 14 studies now under way on migraine treatments.
"There's a lot of
hope," Dr. Diamond says. "There's going to be more and more
help and better drugs, and drugs suitable to more people."
Still, millions of
sufferers are not getting the newer, proven medications for
their migraines.
One reason: Experts
say about half of the estimated 30 million Americans with migraines
are never properly diagnosed.
"It's an awareness
issue, and I do think people are suffering needlessly," says
Dr. Diamond, founder and director of the Diamond Headache Clinic
in Chicago.
On a more positive
note, the number of physician visits for migraines nearly
doubled from 9.4 people per 1,000 to 18 per 1,000, from 1990
to 1998, a recent Wake Forest University study says. This jump
in visits may reflect the newer treatment options.
However, the study
also found that many migraine sufferers rely on too many addictive
painkillers that provide only short-term relief.
Dr. Mannix says that
about 25 percent of migraine patients could benefit from preventive
medications, such as anti-seizure drugs, but only 5 percent
take them.
Besides medication,
practical steps such as eating and sleeping well, exercising
regularly, and reducing stress can help fight migraines, specialists
say.
Always consult your
physician for more information.
How
a Migraine Happens
Although there is
general agreement among healthcare providers and researchers
that a key element in migraines is blood flow changes in the
brain, the exact cause of migraine headaches remains unknown.
According to the National
Institute of Neurological Disorders and Stroke (NINDS),
one theory of how a migraine happens is as follows:
The nervous system
responds to a trigger by creating a spasm in the nerve-rich
arteries at the base of the brain. The spasm closes down or
constricts several arteries supplying blood to the brain, including
the scalp artery and the carotid (neck) arteries.
When the arteries
constrict, blood flow to the brain is reduced. At the same time,
blood-clotting particles, called platelets, clump together in
a process that is believed to release a chemical called serotonin
- which acts as a powerful constrictor of arteries and further
reduces the blood supply to the brain.
When reduced blood
flow decreases the brain's supply of oxygen, symptoms signaling
a headache, such as distorted vision or speech, may result.
Reacting to the reduced
oxygen supply, certain arteries within the brain open wider,
or dilate, to meet the brain's needs. The dilation spreads,
finally affecting the neck and scalp arteries.
Dilation of these
arteries triggers the release of pain-producing substances,
called prostaglandins, from various tissues and blood cells.
Chemicals that cause inflammation and swelling, and substances
that increase sensitivity to pain, are also released.
The circulation of
these chemicals and the dilation of the scalp arteries stimulate
the pain-sensitive nociceptors. The result is a throbbing pain
in the head.
Always consult your
physician for more information.
Online
Resources
(Our Organization
is not responsible for the content of Internet sites.)
American
Academy of Ophthalmology
American
Council for Headache Education
Glaucoma
Research Foundation
National
Eye Institute (NEI)
National
Institutes of Health (NIH)
National
Institute for Neurological Disorders and Stroke (NINDS)
US
Department of Heath and Human Services
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