Glaucoma In Seniors
Last Updated: April 2, 2013
By Jeannette Franks, PhD
Glaucoma is a cluster of diseases that can damage the eye's
optic nerve and result in irreversible vision loss-and ultimately
can cause total blindness. It is one of the leading causes of legal
blindness in the US and probably the most preventable cause of
vision loss. Glaucoma tends to run in families and most often
occurs in people over the age of 60. As baby boomers age, we can
anticipate more and more cases of glaucoma in seniors.
Anyone can get glaucoma, but for reasons that are not fully
understood, it is more common in people of African-American and
Mexican-American ancestry. In addition to family history, other
risk factors include nearsightedness (myopia), previous eye injury,
low blood pressure,
diabetes, and long exposure to cortisone, a steroid
hormone.
Our eyes contain fluid which maintains a constant pressure
within the eyeball. When the valve that regulates this liquid, and
thus the pressure, malfunctions, the optic nerve becomes damaged by
the increased pressure in the eye. This process is painless and
gradual, and vision usually seems normal as it's happening.
Common Types of Glaucoma in Seniors
There are several types of glaucoma. The most common
isopen-angle glaucoma, which results in a slow, painless loss of
peripheral vision. Approximately 1 percent of all Americans have
this type.
Try this: sit looking straight ahead and extend your arms out
from your sides, parallel to the floor. Gaze straight ahead and
wiggle your fingers. Can you see them? Try pulling your arms back
to see how far your side vision goes. Slowly move your arms toward
the center. Most of us can see our fingers move when our arms are
lined up at right angles to our bodies, as if up against a wall.
But since you've probably never tried to examine your peripheral
vision before, you could be gradually losing it without
noticing.
Withopen-angle glaucoma, one's field of vision slowly,
imperceptibly narrows as peripheral vision deteriorates. Vision
damaged this way is often compared to looking through a tunnel, but
it is actually more akin to looking at the world through a paper
towel tube.
Low-tensionornormal tension glaucomais more challenging to
detect because the intraocular pressure is within normal
parameters. It is thought to be related to impaired blood flow to
the optic nerve.
Over a half a million people in the US suffer fromangle-closure
glaucoma.If intraocular pressure becomes too high, the iris is
forced against part of the eye and blocks drainage. When the
drainage becomes completely blocked, it will result in
anacuteglaucomaattack, which can lead to vision loss very quickly.
This sudden increase in intraocular pressure is accompanied by pain
in the eye itself, headache, and vomiting. This medical emergency
requires calling 911 promptly and getting to the emergency room as
soon as possible. Angle-closure glaucoma is uncommon and occurs
more frequently in those of Asian and Inuit descent.
An acute glaucoma attack occurs often in a movie or other
darkened room, because the pupil dilates in the dark. As the pupil
increases in size, there is an increase in the contact between the
eye's lens and the iris. This narrows the drain. The pupil also
dilates during times of extreme stress or fear. Some medications,
such as anti-depressants, cold medications, antihistamines, and
anti-nausea drugs can also cause dilation of the pupil and lead to
an attack of acute glaucoma.
With a minor attack there is a slight blurring of vision and
rainbow-colored haloes around lights, but no pain or redness.
Rare Types of Glaucoma
Pigmentary glaucomamost often affects nearsighted people and men
more than women. It might begin even in the early twenties or
thirties and is particularly threatening to vision over a
lifetime.
A common cause of glaucoma in people of European descent
isexfoliation syndrome. In perhaps 10 percent of this population
over age 50, flakes of whitish material build up on the lens of the
eye. This can clog the normal drainage and cause an increase in
intraocular pressure.
Trauma-related glaucomais from any serious blow to the eye,
chemical burn, or penetrating injury. It is crucial for anyone who
has experienced eye-trauma to have complete eye exams at regular
intervals recommended by an eye care specialist or
ophthalmologist.
Detecting Glaucoma in Seniors
Only a full vision exam, including tonometry, visual field exam,
visual acuity, and a dilated eye exam can determine if one has any
of these types of glaucoma. Tonometry measures the ocular pressure
by determining the resistance of your cornea to indentation,
usually by directing a quick, painless puff of air at the eye. A
visual field exam tests the full field of vision by asking if you
can see a series of objects or flashes of light in various
locations, for example on a computer screen. The visual acuity exam
starts with the familiar eye chart with the tumbling E's.
The dilated eye exam is where drops are put in the eyes to
dilate (widen) the pupils so that the physician can examine the
retina and optic nerve. The drops may cause blurring of vision for
several hours, although most people are still able to drive
afterwards.
The American Academy of Ophthalmology recommends a full eye exam
for everyone under 40 every five to ten years; after the age of 40
every two to four years, and annually after the age of 55. Full
exams are recommended annually for those over 50 with a family
history of glaucoma.
Prevention
It is unclear what can prevent glaucoma in seniors. However, a
2007 study in the journal of the American Academy of Ophthalmology
found a decrease of intraocular pressure (IOP) in rats on a diet
enriched in omega-3 fatty acids and an increase in IOP in rats fed
an omega-3 fatty acid deficient diet. Researchers had noted that
traditional Western diets are low in omega-3 fatty acids while
omega-3 fatty acids are quite high in the fish-rich Japanese diet.
IOP increases with age in Western populations, while it actually
decreases with age in Japan. Studies on humans at the present time
are limited. Wild salmon, tuna, herring, mackerel, anchovies, and
sardines are good natural sources of omega-3 fatty acids. Fish oil
supplements are also high in omega-3 fatty acids.
The single most important thing one can do to prevent vision
loss from glaucoma is to have regularly scheduled full eye
exams.
Treatment
There is no cure for glaucoma. All types of glaucoma are
controlled with medications (usually eye drops, but can be oral as
well) and surgery. Several of the more commonly prescribed
medications include:
- Alpha-adrenergic agonists such as Alphagan®,
Iopidine®, and Propine®. Possible side
effects are stinging of the eye at application, fatigue, headache,
drowsiness, dry mouth, dry nose, and allergic reactions.
- Beta blockers such as, Timoptic®,
Betoptic®, Betagan®, and
OptiPranolol®. Possible side effects include low blood
pressure, reduced pulse rate, and fatigue.
- Carbonic anhydrase inhibitors such as Azopt®,
Trusopt®, and Diamox® (taken orally).
Possible side effects include tingling in the hands and feet, upset
stomach,
memory loss and problems,
depression, and kidney stones.
It is essential that the medication be taken exactly as
prescribed and that the annual exam includes a medication review.
Some drugs stop working over time or may have negative interactions
with other prescriptions. Only a physician can appropriately
monitor glaucoma and glaucoma medications.
Often an older person will need help with eye drops because of a
tremor or fine motor control issues. Special devices can help make
the application of drops easier. Check out the Community Services
for the Blind catalogue with the "eye drop guide" (http://www.sightconnection.com/).
Memory problems increase the risk of missing medications
dramatically. Remember, vision lost from glaucoma is lost forever;
it is irreversible. A family member or trained aide must assist a
memory-impaired person with glaucoma medicationevery day.
Based on recent reviews by the National Eye Institute and the
Institute of Medicine, a task force on complimentary therapies
found no scientific evidence that proved increased benefits of
marijuana use to treat glaucoma compared to the wide variety of
prescription medications available. While marijuana does indeed
lower intraocular pressure, a person would need to smoke a
marijuana cigarette eight to ten times a day. Medical marijuana is
still illegal in most of the US.
Laser surgery is another treatment option for glaucoma in
seniors. Using a laser, part of the anterior chamber is changed to
make it easier for the fluid to exit the eye. Usually the patient
will also continue to take glaucoma medications and monitor
intraocular pressure with an annual exam.
Low Vision Rehabilitation
Because vision lost to glaucoma cannot be restored, it is
imperative for people with glaucoma-related vision loss to
understand and utilize low vision rehabilitation. New training and
technology can help make the most of remaining vision. Many
community organizations and agencies offer information about low
vision counseling, vision and technology training, support groups,
and other special services for people with visual impairments. An
excellent initial contact to find low vision rehabilitation in your
area is the national senior information helpline: 1-800-766-1116 or
http://www.eldercare.gov.
A physician may say to someone with glaucoma who has experienced
permanent vision loss, "You're legally blind, and there's nothing I
can do." This is devastating news to anyone, and the person hears,
"there's nothing I can do" and thinks that there's nothing more to
be done. However, what the doctor should say is, "there's no way
I can restore your
lost sight, but experts in low vision can help you make the most of
the vision you still have."
Legally blind is specifically defined as 20/200 in the best eye
with the best corrective lenses. For example, with my lovely new
bifocals, I have 20/20 vision. A sign that I can read 200 feet
away, a legally blind person with 20/200 vision would need to walk
up to the sign until 20 feet away to be able to read itwithhis or
her best glasses. Most people who are thought of as blind have some
functional vision.
For people with total blindness, mobility training, instruction
in activities of daily living, and social services are also widely
available.
My first job in social services was at Seattle's excellent
Community Services for the Blind and Partially Sighted. I assure
you that blind and visually impaired people lead lives as full and
fun and productive as those of us who are completely sighted. My
many mentors worked, played, raised families, and struggled with
their lives no more or less than the rest of us. For their wisdom,
insight, and inspiration, I thank them.
For more information on glaucoma in seniors, contact the
Glaucoma Foundation at http://www.glaucomafoundation.org/index.php
Jeannette Franks, PhD, is a passionate gerontologist who teaches
at University of Washington and Bastyr University; she is the
author of a book on assisted living and numerous
articles.
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