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Dry eye
see also:-
What Is "Dry Eye?"
Yours eyes are a delicately balanced Eco-system in which tears play
a large and important role. Every time you blink, tears form a coating
that protects and nourishes the eyes' surface. When tear production
is reduced, your eyes feel dry, scratchy and irritated.
Dry Eye, a condition that affects millions of people, is actually
a group of conditions with a variety of causes. It may result when
the eyes produce too little tear fluid, or when tears evaporate
from the surface of the eye too rapidly.
Decreased tear production is particularly common in older adults,
especially women. Some diseases, such as arthritis, can also lead
to decreased tear production; and many medications can cause this
as a side effect. Long term contact lens wear, certain infections,
and certain types of surgery can decrease tear production as well.
Increased tear evaporation most commonly results from a dysfunction
or inflammation within the eyelid margins themselves - a condition
called Meibomian Gland Dysfunction/Meibomianitis/Blepharitis.
People with large eyes are also subject to high tear evaporation
(eg patients with Thyroid eye disease).
Environmental conditions such as heating, air conditioning, and
wind, and activities that decrease blink rate, such as driving,
watching TV, or reading, all increase tear evaporation as well.
In all these dry-eye conditions the normal tear fluid loses water
and becomes more concentrated. As a result of the tears "pull"
water out of the surface of the eye, causing the dry-eye symptoms
that usually worsen as the day goes on.
Do you suffer from Dry Eye Syndrome?
Instructions: Check the box for the symptoms or conditions you may
have recently experienced. Please review this checklist with your
Eye Specialist to determine if you need to be tested for Dry Eye
Syndrome.
· Dryness of the eye
· Mucous discharge
· Redness
· Sandy or gritty feeling
· Itching
· Burning
· Constant or occasional tearing
· Watery eyes
· Light sensitivity
· Eye pain or soreness
· Lid infections
· Sties
· Tired eyes
· Contact lens discomfort
· Contact lens solution sensitivity
Related Conditions:
· Sinus congestion
· Nasal congestion
· Runny nose
· Post-nasal drip
· Chronic cough
· Bronchitis
· Allergies or hayfever
· Frequent colds
· Middle ear congetsion
· Sneezing
· Dry throat or mouth
· Headaches
· Asthma
· Muscle pain
Important reminders for Dry Eye Sufferers
Among those who suffer from Dry Eye Syndrome and related tearing
disorders, nearly half also experience realated symptoms involving
the nose, throat, and sinus.
These include:
· Nasal or sinus congetsion, post nasal drip, and sneezing.
· Allergy and hayfever symptoms.
· Middle ear congestion.
· Chronic coughing.
· Headaches.
Two types of tears.
Your eyes are lubricated by two different types of tears produced
by the tear glands in your upper and lower eyelids.
Constant tears are continuously produced to lubricate the eye at
all times, and contain natural antibiotics to fight infections.
Reflex tears are only produced in response to irritation, injury
or emotion to help rinse the surface of the eye.
A delicate balance between constant and reflex tears, in addition
to a satisfactory blink reflex, helps ensure that your eyes will
be comfortable, well-lubricated and well-protected.
If you experience one or any combination of the following symptoms,
you may be suffering from a medical condition known as Dry Eye:
o Burning & Stinging
o Gritty feeling when there is nothing in your eye
o Dryness
o Itching
o Sensitivity to bright lights
o Mucous secretions in the eye
Ironically, the tear producing glands sometimes react to the dry,
scratchy feeling by watering more than ever. But these "reflex
tears" do not relieve the dryness as they lack some of the
natural components that are essential to lubricate the cornea properly.
What Causes Dry Eye?
There are many possible causes of dry eye. The most common include:
The Aging Process
As we grow older, our eyes produce fewer lubricating tears. In fact,
the volume of lubricating constant tears can be as much as 60% less
at age 65 than at age 18. This reduction in constant tear flow and
resulting eye irritation may cause occasional excessive reflex tearing.A
condition associated with arthritis, known as Sjogren's syndrome,
can also dry out the mouth and the eyes.
Menopause & Pregnancy
While men and women of any age can be affected, women are more prone
to develop dry eyes after menopause and during pregnancy.
Contact Lenses
Contact lens wear can dramatically increase tear evaporation, causing
irritation, infection, protein deposits, and discomfort. Research
shows that dry eye is the lending cause of contact lens discomfort.
Medication
Common medications such as decongestants, antihistamines, diuretics,
beta-blockers, sleeping pills, anti-depressants, pain relievers,
and alcohol can cause decrease in tear secretion. Frequent use of
preserved eye drops or artificial tears can also aggravate dry eye
conditions.
Environment
Just about everywhere you turn in this world, you run into something
that can dry out your eyes. These include sunny, windy, dry conditions;
heaters, dehumidifiers, fans or air conditioners, high altitudes;
smoke or air pollution; sand, dust, or airborne pollen. The list
is virtually endless.
Diagnosing Dry Eye Syndrome
Your optometrist may use a combination of several methods to determine
whether you have Dry Eye.
Eye Drops
A few drops containing dye in each eye will help your optometrist
check for any dry spots or areas where the cornea has become damaged
by dehydration. Using a microscope he can evaluate both the quality
and the quantity of your tears.
Schirmer Test
This simple, painless test assesses tear volume. By placing the
tip of a specially treated strip of paper in the lower lid of your
eye, your doctor is able to measure the amount of tears your eye
produces in a given period.
Temporary Closing of Tear Ducts
In this method, your physician inserts small dissolvable collagen
plugs into your tear ducts to prevent tear drainage and allow tears
to build up and bathe the eyes. Collagen plugs dissolve in just
a few days. If you get relief from your symptoms during this test
period, your physician may recommend permanent closure of your tear
ducts with long-term plugs.
Short-term Relief with Artificial Tears
For patients with less severe dry eye symptoms, artificial tears
can often offer immediate relief. Unfortunately, this remedy is
usually temporary. While artificial tears may soothe the eyes initially,
they can increase the possibility of infection by washing away the
natural infection-fighting tear film of the eye.
This is why patients with more severe cases of dry eye may benefit
from having their tear ducts permanently closed. This long-term
solution allows patients to use their own natural tears to treat
their condition.
Long-term Relief with Punctal Plugs
There is a simple non-surgical procedure that provides long-term
relief of Dry Eye that involves the use of permanent, yet removable
plugs called punctal plugs.
There are a number of reasons why punctal plugs have become the
most popular method of treating dry eye. They have a very high rate
of success; and the optometrist can insert them easily and painlessly.
They are also reversible if too much tearing is produced.
The idea behind punctal plugs is simple. Tiny, non-dissolvable plugs
are inserted into your tear drainage ducts (puncta) where they act
as a dam. Therefore, your precious tears have no other way place
go except onto the surface of your eyes.
Diagram of the EAGLE-VISION Punctal Plug into the drainage system
of the lower eyelid.
Diagram of the Herrick Canicular Plug in the drainage system
of the lower eyelid
More than 300,000 dry eye sufferers have been successfully treated,
through punctal and canalicular occlusion.
Here's how they work:
By blocking the tear drains, more natural infection-fighting tears
bathe and soothe the eye, which may eliminate the need for eye drops
altogether. Punctal Plugs can also reduce or eliminate the major
cause of contact lens discomfort.
Eye drops and artificial tears in general temporarily soothe the
symptoms of Dry Eye Syndrome. Sometimes, these solutions can actually
wash away the natural infection-fighting tear film on the eye. Also
most artificial tears contain preservatives which can disrupt the
mucous layer of the tears, that is required to hold your natural
tears in place on the eye.
THERA TEARS
If you have sandy, gritty irritated eyes or burning eyes, and these
symptoms get worse as the day goes on, you're probably one of the
millions with the problem eye doctors call "dry eye."
Now, after years of research, the good news is that we finally understand
dry eye, and there is something you can do about it.
Why Does Your Eye Need Tears Anyway?
Did you ever wonder why the eye is covered by tears? It's because
the delicate living tissue on the surface of your eye has no blood
supply-it has a tear supply instead. So rather than getting important
things like oxygen and electrolytes from the blood, your eye surface
gets them from the watery layer of your tears.
What Happens In Dry Eye?
In dry eye the tear film on the eye surface loses water because
of either decreased tear production or increased evaporation. And
as evaporation continues throughout the day, your eyes feel drier
and drier.
What Causes Dry Eye?
The most common cause of dry eye is aging. As we get older we produce
fewer tears, and evaporation increases. Other common causes include
contact lens wear, sun, wind, dry air, reading, computer use and
certain medications. Dry eye is seen with certain diseases such
as Sjögren's syndrome as well.
20 Years of Clinical Research, testing and development by an eye
physician focused on one goal: to develop an effective medication
for dry eye. The result: a medical breakthrough called TheraTears.
TheraTears has the extra water needed to rehydrate the tear film
and quench dryness of the eye, and the patented electrolyte balance
that promotes natural healing and provides dry-eye relief.
Preservative-free TheraTears Works Two Ways:
Hypotonic - More Moisture Per Drop
Each drop of TheraTears contains extra water, relative to its other
ingredients, to more effectively quench dryness of the eye.
Patented Balance of Electrolytes
The eye surface depends upon the tears for a special balance of
electrolytes. By providing your eyes with this electrolyte balance,
and the extra water needed to rehydrate your tear film, TheraTears
creates the environment needed to promote natural healing and provide
dry-eye relief.
TheraTears in preservative-free single-use containers is designed
to saturate dry eyes, providing the dosing that is ideal for very
dry eyes. For maximum hydration and relief of dryness, doctors may
recommend saturation dosing--splitting the entire contents of one
container, in both eyes within a 5-minute period after opening at
least 4 times a day.
TheraTears Liquid Gel is a thicker version of TheraTears that is
perfect for night time, or for those who need a longer-lasting protective
film during the day. Because TheraTears Liquid Gel is so long-lasting,
it is formulated without a preservative so that unlike preserved
gels, there never needs to be a concern regarding preservative-induced
irritation. And because of its patented electrolyte balance, you
will never experience the "electrolyte imbalance toxicity"
you may get from other products..
TheraTears Nutrition for Dry Eyes (Omega-3 supplement with EPA and
DHA-enriched flaxseed oil) provides the foundation for every dry-eye
treatment program. The oil glands in the eyelid are critical to
tear film structure and eye comfort. TheraTears Nutrition for Dry
Eyes provides a special blend of pharmaceutical grade Omega-3 essential
fatty acids that your eyes, lids and tear film need to function
their best, but your body cannot produce. And most of us don't get
enough Omega-3s from our diet. TheraTears Nutrition provides these
Omega-3s for eye comfort upon awakening and continued eye comfort
throughout the day.*
Whatever the cause for your dry eye (for example, wind, sun, age,
surgery, contact lens wear, computer use, medication side effects),
and no matter how mild or severe, your dry eye just doesn't stand
a chance when you use the TheraTears treatment program.
TheraTears in preservative-free single-use containers is designed
to saturate dry eyes, providing the dosing that is ideal for very
dry eyes. For maximum hydration and relief of dryness, doctors may
recommend saturation dosing--splitting the entire contents of one
container, in both eyes within a 5-minute period after opening at
least 4 times a day.
*These statements have not been evaluated by the FDA. This product
is not intended to diagnose, treat, cure or prevent any disease.
Each 2 softgels contain 100 IU of Vitamin E, 500 mg of Flaxseed
Oil, 225 mg of EPA (Eicosapentaenoic Acid from Fish Oil) and 50
mg of DHA (Docosahexaenoic acid from Fish Oil). Two softgels provide
10.2 calories.
Treating Dry Eye Will Never be the Same
How an EPA-enriched Flaxseed Oil Supplement Treats Dry Eye
(by Jeffrey P. Gilbard, MD )
By decreasing inflammation, and augmenting the oil and water layers
of the tear film, omega-3 supplementation with EPA-enriched flaxseed
oil promises to provide the foundation for a broad spectrum of dry
eye treatment regimens.
Omega-3s are essential fatty acids that your body can't produce.
Your body must obtain them from your diet. Unfortunately, the Western
diet is deficient in Omega 3s. we just don't eat enough salmon and
other cold-water fish. It has been estimated that 83% of Americans
are deficient in Omega-3s. The two best sources of Omega-3s are
fish oil and flaxseed oil, and Omega 3s have a multitude of health
benefits.
Omega-6s are another group of essential fatty acids. Americans obtain
an excess of these through their consumption of beef, dairy, vegetable
cooking oils, and vegetable shortenings (i.e. cookies, potato chips,
snacks etc.). While the ideal dietary ratio of Omega-3s to Omega-6s
is about 1:1, the existing ratio in the American diet is about 1:20.
Let's have a closer look at how Omega-3s address the root causes
of meibomitis and dry eye.
Omega-3s and Dry Eye
First Mechanism-Decrease Inflammation
Once eaten, Omega-3s are acted upon by enzymes in the body to produce
prostaglandin E3 (PGE3) and leukotriene B5 (LTB5) (Figure 1). These
are two eicosanoids * that decrease inflammation. In addition, and
perhaps more importantly, Omega-3s have been shown, in cartilage,
to produce a dose dependent decrease in the gene expression and
activity of proteoglycan degrading enzymes (aggrecanases), the gene
expression of pro-inflammatory interleukin-1alpha (IL-1alpha), interleukin-1beta
(IL-1beta), tumor necrosis factor-alpha (TNF-alpha), and cyclooxygenase
(COX-2) (Figure 2). There is an abundance of clinical evidence that
ingestion of Omega-3s decreases the inflammation seen in the joints
in rheumatoid arthritis3-6 and in the skin in dermatitis as well.7
Not surprisingly given the cartilaginous tarsal plate, reports are
emerging to indicate that consumption of Omega-3s decrease the inflammation
of meibomitis.8 As a result, meibomitis patients taking Omega-3
supplements have experienced relief from eye irritation upon awakening
in the morning.
*Eicosanoids are oxygenated fatty acids that act as local hormones
that act near their site of synthesis. Eicosanoids are derived from
arachidonic acid (AA), dihomo-gamma-linoleic acid (DGLA) and eicosapentaenoic
acid (EPA).
Second Mechanism-Augment Oil Layer
Second, essential fatty acids are used by the meibomian glands in
the eyelid to manufacture the oil layer of the tear film. HPLC/mass
spectrometry studies have shown that the polar lipid profiles of
meibomian gland secretions in female Sjögren's patients are
controlled by the dietary intake of omega-3 essential fatty acids.
Patients with high intakes of omega-3s show a single-prominent-peak
polar lipid pattern whereas patients with low dietary intake show
multiple smaller peaks. 9 It seems reasonable to surmise that dietary
omega-3s are being utilized in the production of meibomian secretions
and are contributing to and augmenting the tear film oil layer.
Clinical reports have observed clearer and thinner oils with omega-3
treatment.8 With an improved supply of Omega-3s, the oils produced
by the meibomian glands flow better and therefore create a better
oil layer covering for the tear film. The improvement of the oil
layer provides dry-eye relief for patients with meibomian gland
dysfunction.
Third Mechanism-Stimulate Tear Secretion
The essential fatty acid metabolic pathways are dynamic, complex
and interrelated. Levels of certain omega-3s for example, can influence
activity in the metabolism of omega-6s. The most important example
of this is the activity of eicosapentaenoic acid (EPA) (Figures
1 and 2). It is EPA that has been shown, in cartilage, to produce
a dose dependent decrease in the gene expression and activity of
proteoglycan degrading enzymes (aggrecanases), the gene expression
of pro-inflammatory interleukin-1alpha (IL-1alpha), interleukin-1beta
(IL-1beta), tumor necrosis factor-alpha (TNF-alpha), and cyclooxygenase
(COX-2) (Figure 2). In addition, EPA also inhibits the arachidonic
acid inflammatory cascade (Figure 2). But EPA plays another role
as well. Specifically, EPA competitively inhibits the conversion
of DGLA to arachidonic acid (AA), and in doing so, promotes the
conversion of DGLA to PGE1. Why is this desirable? First, PGE1 has
anti-inflammatory properties,10,11 further helping to reduce meibomitis
and associated ocular surface inflammation. More importantly, PGE1
acts on G protein-coupled receptors designated E-prostanoid or "EP"
receptors. Specifically, PGE1 binds to EP2 and EP4 receptors to
activate adenylate cyclase to increase cyclic AMP (cAMP).12 PGE1
has been shown to stimulate aqueous tear production in rabbits,13
and cAMP has been shown to stimulate aqueous tear secretion in dry
eye patients.14,15
There have been some attempts to treat dry eye with the omega-6
essential fatty acid gamma linolenic acid (GLA) found in black currant
seed oil, evening primrose oil and borage oil. There are two published
studies that concluded GLA was not effective in treating dry eye.16,17
Moreover, there are risks in long-term GLA and omega-6 supplementation
related to the accumulation of arachidonic acid (inflammation, thrombosis
and immunosuppression).18-20
By decreasing inflammation, and augmenting the oil and water layers
of the tear film, omega-3 supplementation with EPA-enriched flaxseed
oil promises to provide the foundation for a broad spectrum of dry-eye
treatment regimens. Studies are now underway with TheraTears Nutrition,
a highly refined patent pending EPA-enriched flaxseed oil, to fully
evaluate the magnitude of its efficacy in treating dry eye patients.
Footnotes
1Simopoulos AP. Omega-3 fatty acids in health and disease and in
growth and development. Am J Clin Nutr 1991;54:438-463.
2James MJ. Dietary polyunsaturated fatty acids and inflammatory
mediator production. Am J Clin Nutr 2000;71(suppl):343S-8S.
3James MJ, Cleland LG. Dietary n-3 fatty acids and therapy for rheumatoid
arthirits. Semin Arthritis Rheum Oct 1997, 27(2):85-87.
4Volker D, et al. Efficacy of fish oil concentrate in the treatment
of rheumatoid arthritis. J of Rhem Oct 2000, 27:2343-2346.
5Fortin PR et al. Validation of a meta-analysis: the effects of
fish oil in rheumatoid arthritis. J of Clin Epidemiology 1995, 48:1379-1390.
6Kremer JM et al. Effects of high-dose fish oil on rheumatoid arthritis
after stopping non-steroidal anti-inflammatory drugs. Arthritis
& Rheumatism 1995,38:1107-1114.
7Goodman J. The Omega Solution. Prima Publishing, Roseville, California.
2001:p4-5.
8Boerner CF. Dry eye successfully treated with oral flaxseed oil.
Ocular Surgery News, October 15, 2000, p147-148.
9Sullivan RM et al. Correlations between nutrient intake and the
polar lipid profiles of meibomian gland secretions in women with
Sjogren's Syndrome. Third International Conference on the Lacirmal
Gland, Tear Film and Dry Eye Syndromes: Basic Science and Clinical
Relevance. Maui, Hawaii, November 15-18, 2000.
10De Perrot M et al. Prostaglandin E1 protects lung transplants
from ishemia-reperfusion injury: a shift from pro- to anti-inflammatory
cyctokines. Transplantation 2001 72(9):1505-1512.
11Kotani N et al. Intraoperative prostaglandin E1 improves antimicrobial
inflammatory responses in alveolar immune cells. Crit Care Med 2001
29(10):1943-1949.
12Narumiya S et al. Prostanoid receptors: Structures, properties,
and functions. Physiol Rev 1999;7:1193-1226.
13Pholpramol C. Secretory effect of prostaglandins on the rabbit
lacrimal gland in vivo. Prostaglandins Med 1979;3:185-192.
14Gilbard JP et al. Stimulation of tear secretion by topical agents
that increase cyclic nucleotide levels. Invest Ophthalmol Vis Sci.
1990; 31:1381-1388.
15Gilbard JP, Rossi SR, Gray Heyda K, Dartt DA. Stimulation of tear
secretion and treatment of dry eye disease with 3-Isobutyl-1-methylxanthine.
Arch Ophthalmol. 1991; 109:672-676.
16Oxholm P et al. Patients with primary Sjogren's syndrome treated
for two months with evening primrose oil. Scand J Rheumatol 1986;15(2):103-8.
17Theander E et al. Gammalinolenic acid treatment of fatigue associated
with primary Sjogren's syndrome. Scand J Rheumatol 2002;31(2):72-9.
18Johnson MM et al. Dietary supplementation with g-linolenic acid
alters fatty acid content and eicosanoid production in healthy humans.
J Nutri 1997;127:1435-1444.
19Phinney S. Potential risk of prolonged gamma-linolenic acid use.
Ann Intern Med 1994;120:692-
20Yam et al. Diet and disease-the Israeli paradox: Possible dangers
of a high omega-6 polyunsaturated fatty acid diet. Is J Med Sci
1996;32:1134-1143.
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