How Do Tears Prevent Dry Eyes?
Tears are a major protective agent for the eyes. They wash away dust and soothe the eyes, providing oxygen and nutrients to the cornea, as well as helping prevent eye infections.
Tears are composed of three layers.
The outer lipid layer consists of an oily film that prevents evaporation and keeps the eye lubricated.
The middle layer is made of mostly water that moisturizes the eyes and some nutrients and proteins that help prevent eye infections.
The inner layer contains mucous that helps the tear film spread and maintain on the eye.
Each layer is vital to the health of the eyes.
“Get the Red Out” Drops
Hoping to help dry eyes, people sometimes use eye drops that “get the red out.”
Such drops can reduce or eliminate the redness temporarily, but they don’t treat the cause of the redness.
Additionally, the vasoconstrictors in these formulas that reduce redness by contracting the blood vessels in the eye are addictive, in the sense that, more and more use of these drops are required to achieve the same effect. And, with frequent use, the effect diminishes anyway, leaving the user with red eyes because the blood vessels simply will not constrict as much as they did when the drops were first used.
Dry Eye Syndrome
Dry eye syndrome is a chronic lack of sufficient lubrication and moisture in the eye. Its consequences range from subtle but constant irritation to ocular inflammation of the anterior (front) tissues of the eye.
Dry eyes may signify more than just discomfort. Serious vision complications are a possibility if you have untreated chronic dry eye syndrome. Such complications may include dehydration of the corneal surface, ulceration and perforation of the cornea, an increased incidence of infectious disease and, potentially, serious visual impairment and/or blindness. For these reasons, the diagnosis and appropriate treatment of dry eyes is important.
When tears do not adequately lubricate the eye, a person may experience:
•Persistent dry eyes
• Gritty sensation of the lids
• A feeling of a foreign body or grain of sand in the eye
• Blurred, changing or decreased vision
• A stringy discharge from the eyes
• Intermittent episodes of excessive tearing followed by periods of very dryeyes
• Discomfort after watching television, reading, sewing, computer use, etc.
Tears bathe the eye, continuously washing out dust and debris and keeping the eye moist. Tears contain enzymes that neutralize micro-organisms that colonize in the eye. In dry eye syndrome, the eye does not produce adequate tears, or the tears have a chemical composition that causes them to evaporate too quickly.
Tears are composed of three layers: the outer, oily, lipid layer; the middle, watery, lacrimal layer; and the inner, mucous or mucin layer. Each layer of tears is produced by a different component of the eye, so a problem with any of those sources may
result in dry eyes.
Dry eye syndrome can be caused or aggravated by a variety of conditions. Dry eyes may occur:
• As we age, we produce less tears and they evaporate faster.
• During menopause due to change in hormones.
• As a side effect of many medications, such as antihistamines, antidepressants, certain blood pressure medicines, Parkinson’s medications and birth control pills.
• Environmental factors such as dusty air, dry or windy weather, air conditioning and heating, or fumes.
• Contact lens wear because the lenses absorb lubrication and tear film.
• Insufficient blinking, such as staring at a computer screen all day.
• Lack of sleep as the eyes are not allowed to rest and bathe in naturaltears.
• Eyelid disease or incomplete closure of the eyelids.
• Following a chemical burn to the eye.
• A deficiency in Vitamin A.
• Deficiency of the tear-producing glands.
While there are a variety of methods available for diagnosing “dry eye syndrome,” one of the first tests usually performed is the Schirmer’s test. This test involves placing a strip of testing filter paper inside the lower part of the eyelids. The lids are closed and, after a few minutes, the filter paper is removed and examined. Less than the normal amount of wetting, on repeated examinations, indicates decreased tear production. Other diagnostic tests include application of fluorescein “dye” drops that can be traced with a special light as they wash out of the eye through blinking. Tears may also be examined to see if they contain enough moisture, proteins, and other materials.
The patient’s medical history often provides the most reliable clues for diagnosis of dry eye syndrome. Your ophthalmologist will carefully examine the eye tissues, and perhaps perform additional tests, to confirm a diagnosis of dry eye syndrome.
Dry eye syndrome is an ongoing condition and treatment will vary depending upon the level of dryness in the eye. The irritating symptoms of dry eye syndrome can be managed. Your ophthalmologist will help you determine the best course of action for alleviating your particular symptoms.
Artificial Tear Drops and Prescription Ointments: The use of over-the-counter artificial tears is a primary treatment for dry eye. No one drop works for everyone.
Your optometrist or ophthalmologist will know which formulas are effective and longlasting and which ones are not, as well as which eye drops will work if you wear contact lenses. If you have chronic dry eyes, it is important to use the drops even
when your eyes feel fine, to keep them lubricated.
If your eyes dry out while you sleep, your ophthalmologist may prescribe a thicker lubricant, such as an ointment, to use at night.
RESTASIS®: Available by prescription, Restasis Ophthalmic Emulsion eye drops go one step further than artificial tears. Restasis helps your eyes increase natural tear production. Restasis treatment is the first of its kind.
Temporary Punctal Occlusion: The puncta is the opening at each (lacrimal) tear duct on the eyelid margin. Tiny plugs (lacrimal/punctal plugs) can be placed inside the tear ducts in the upper and/or lower lids to block tear drainage from the eye. The use of punctal plugs can be an effective step in treating moderate to severe dry eye that is unresponsive to artificial tear drops and ointments. The tears drain into the
nose via the tear ducts; therefore, blocking this outflow is a reasonable strategy to keep tears in the eye for a longer time.
Permanent Punctal Occlusion: If temporary plugging of the tear drains works well, more permanent silicone lacrimal/punctal plugs may be a good option. The plugs will hold tears around the eyes as long as they are in place. They can be removed ifnecessary. Rarely do the plugs come out spontaneously or migrate down the tear drain. Many patients find that the plugs improve comfort and reduce the need for artificial tears.
Surgical Punctal Occlusion: When temporary or permanent punctal plugs fail to remain in place, another option is surgical closure of the tear ducts to allow tears to remain around the eye. This is done with local anesthetic on an outpatient basis.
There are no limitations in activity after having this surgery.
Nutrition: Your ophthalmologist may recommend special nutritional supplements for dry eyes. Studies have found that supplements containing certain essential fatty acids (linoleic and gamma-linolenic) can decrease dry eye symptoms. You could also eat more cold-water fish, such as sardines, cod, herring, and salmon, which contain omega-3 fatty acids.
Eye or Eyelid Disease: Treating any underlying eyelid disease or infection, such as blepharitis, is important when controlling the symptoms of dry eye syndrome. While you may not even recognize the symptoms of eyelid disease, your eye doctor will probably see the problem right away and provide treatment such as easy-to-do eyelid scrubs and/or antibiotic or steroid drops.
Medication: When medication is the cause of dry eyes, discontinuing the drug generally resolves the problem. It is important that your physician weigh the benefits of the drug against the side effect of dry eyes. Sometimes switching to a different type of medication alleviates the dry eye symptoms while maintaining the needed treatment. In any case, never switch or discontinue your medications without consulting with your doctor!
Contact Lens Wear: If contact lens wear is the cause of your dry eyes, your ophthalmologist may change the type of lens that you wear or suggest that you wear your lenses for fewer hours each day. In a few cases, it is recommended that contact lens wear be discontinued altogether until the dry eye problem improves.
Environment: If the problem is environmental, it is important that you always wear sunglasses outside to reduce exposure to sun, wind, and dust. Limit your exposure to closed environments with continuously running air conditioning or heating. An air cleaner can filter out dust and other particles from inside the air, while a humidifier adds moisture to air that’s too dry because of air conditioning or heating.
LASIK: If you are considering LASIK, be aware that dry eye syndrome may disqualify you for the surgery, at least until the problem is resolved. Dry eyes increase your risk for poor healing after LASIK, so most surgeons will want to treat the dry eyes first, to ensure a good LASIK outcome. This is true for other types of vision correction surgery, as well.