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:
- Isopen-angle Glaucoma: The most common type of
glaucoma, this results in a slow, painless loss of peripheral
vision. Approximately 1% of all Americans have this type.
- Withopen-angle Glaucoma: With this type, 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 Glaucoma: This
type is 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.
- 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 an acute glaucoma attack, which can lead
to vision loss very quickly.
Rare Types of Glaucoma
There are also several rare types of glaucoma that can affect
- Pigmentary Glaucoma: This most 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.
- Trauma-related Glaucoma: This can be cause by
any serious blow to the eye, chemical burn, or penetrating
Detecting Glaucoma in Seniors
Only a full vision exam, including tonometry, a visual field
exam, visual acuity assessment 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
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
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.
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
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
- Alpha-adrenergic agonists
- Beta blockers
- Carbonic anhydrase inhibitors
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
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
For people with total blindness, mobility training, instruction
in activities of daily living, and social services are also widely
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