Dry Eye Disease
Dry Eye Disease is a disorder of either the quantity or quality of the tear film leading to symptoms of dry, red, burning, gritty, or watery eyes. The eyes may be very light sensitive. Dry eye disease consists of a group of symptoms that develop as a result of other conditions such as eye allergy, medications, arthritis, and environmental factors such as low humidity.
To understand dry eyes, one must first understand the function and components of the tear film. There are three layers of tears on the front of the eye: the oily layer is outermost. It is produced by glands called meibomian (my-BOHM-ee-an) glands, primarily located in the eyelids. It reduces tear evaporation. The second layer is the watery middle layer, which comprises the majority of the thickness of the tear film. This tear layer is produced by the lacrimal (LAK-ri-mal) gland located under the brow bone. This is the watery type of tear that is produced in copious amounts when we cut an onion and our eyes become watery. The innermost layer, which is called the mucin (MEW-sin) layer, is produced by the cells in the conjunctiva (the clear coating over the white of the eyes).
Many dry eye sufferers have watery eyes and don't understand how their eyes can be running with moisture and yet their doctor diagnoses their problem as “dry” eye. This can be explained as a dry eye where the tear glands pump extra amounts of watery tears on the eyes as a protective mechanism to compensate for the dry condition. Eyes that are constantly watery may also have a blocked tear duct.
Dry eye is probably the most common of all eye problems. A recent Harris Poll indicates 33 million U.S. adults are affected by dry eyes, and 89 percent of Americans are unfamiliar with what is probably the most common of all eye disorders.
Adults who have arthritis and other autoimmune disorders are more likely to have dry eyes. Dry eyes accompanied by dry mouth (difficulty swallowing) is called Sjogren’s (SHOW-grins) Syndrome, a condition that occurs more commonly (90%) among women past age forty. In Sjogren’s syndrome, the body’s immune system mistakes its own moisture producing glands for foreign invaders. The immune system then attacks and destroys these glands causing the hallmark symptoms of dry eyes and dry mouth. Like Lupus, Sjogren’s can also damage vital organs of the body with symptoms that may plateau, worsen or go into remission. Some people may only experience the mild symptoms of dry eyes and mouth, while others go through cycles of good health followed by severe disease.
The eyes produce about 40 percent less moisture with advancing age. Certain medications may interfere with tear production (see below). Droopy lower eyelids, as well as excessive computer viewing (decreased blink rate), may expose the surface of the eyes to the air, increasing evaporation and dry eye symptoms.
The first treatment for dry eyes is artificial tears. There are many types of eye drop preparations. It is advisable to avoid artificial tears that have preservatives. Preservatives eventually make your dry eye condition worse. Most preservative-free eye drops come in individual dose vials and you can conveniently carry them around in your pocket or purse. Some of the more viscous (thicker) eye drops last longer on the eye, but your vision is likely to be a little foggy for the first few minutes after putting them in your eyes.
There is no known cure for Sjogren’s syndrome. Moisture replacement therapies can ease the symptoms of dryness. Nonsteroidal anti-inflammatory drugs (NSAIDs), steroids and disease modifying drugs are often used to treat Sjogren’s. Studies by scientists indicate that the male hormone androgen may restore lacrimal gland function and relieve chronic dry eye symptoms. There are some side effects, such as virilism- the growth of facial hair and the manifestation of other male characteristics- in women. Further studies are being conducted to identify an androgen compound that would prevent these side effects.
One of the most practical methods of treating a conventional dry eye is to plug the hole in the tear “sink.” There are tear drainage canals on the edges of the upper and lower eyelids near the nose area. Inside the drainage opening in the lids are tiny pumps that suck away fluid from the surface of the eyes. The lacrimal glands behind the eyelids produce tears. The eyelids spread the tears across the eye's surface, much like a windshield wiper. The drain at the bottom permits the fluid to drain away. If the drain is plugged, more fluid stays on the surface of the eyes. The main problem with this procedure is that, if the tears are “faulty” and lead to inflammation (a major cause of dry eyes), then allowing the inflammatory tears to stay in contact with the eyes longer can actually make the condition worse.
To help conserve moisture on the surface of the eyes, consider some of the following measures:
·Use humidifiers in the home, especially in dry, desert areas.
·Wear wrap-around sun goggles outdoors: Sunglasses (or even clear goggles) with side shields help reduce evaporation by as much as 40 percent.
·Blink your eyes: As you blink you squeeze tears from the glands in your eyelids. Waiting 20-30 seconds in between blinks may cause the breakup of tear film and dehydration.
·Stop smoking: When cigarette smoke is introduced to a room, dry spots on the surface of the eyes occur 40 percent faster than when the lids are held open.
·Avoid smog and fumes: These eye irritants inactivate the enzyme that acts as an antibacterial agent in the tear fluid.
·Check the nose pads on your eyeglasses: If the nose pads are pushing the lower eyelids down they may increase the evaporation of tears. Have an optician adjust the nose pads.
·Tilt the computer monitor: When using a computer terminal, lower the monitor so that the opening in the eyes will be narrow when viewing the screen, thus reducing the surface area of the eyes exposed to the air. See Computer Vision Syndrome sections in this web site.
·Reduce, replace or avoid eye makeup: Eye makeup has been shown to thin the fatty layer on the outer surface of the tear film that keeps the eyes from dehydrating quickly. Eye makeup can harbor bacteria and should be replaced frequently. Gentle removal of all eye makeup nightly is essential.
Check for medications that cause eye dryness: A partial list of these drugs is provided below.
Aspartame (NUTRASWEET), Antihistamines (Benadryl, Coricidin), Atropine, Vitamin A analogs (isotretinoin), Chlorothiazide (diuretics) Codeine, Decongestants (Sudafed), Decongestant eye drops (Visine, Murine, Prefrin, Clear Eyes), Diazepam, valium, lithium (anti-anxiety agents), Hashish (marijuana), Methotrexate and other cancer drugs, Morphine, Practolol, Scopolamine, Tranquilizers (Elavil, Valium), Beta blockers: Timolol, Timoptic, Betoptic, Betagan, Ocupress (glaucoma eye drops)
Check on your soft contact lenses: Soft lenses may promote the evaporation of tears from the surface of the eyes. In severe dry eye cases, contact lenses cannot be worn. However, there are new materials in contact lenses that maintain moisture in the lens longer, so that even marginal dry eyes can be comfortable. Check with your eyecare professional for an evaluation to see if these new lenses can meet your vision needs.
Essential oils are needed in the diet in order to provide lubrication for the joints, the eyes, and to restore normal lubrication to the body. There are good fats and bad fats. The undesired saturated fats are found in meats, fried foods, butter, diary products, and margarine. The good fats are called polyunsaturated fats, especially Omega-6 (non-hydrogenated) and Omega-3 fats found in cold-water fish and flax seeds and walnuts. It is important to maintain the proper balance between the various Omega fatty acids. (see another article in this section on “Fatty Acids- The Good, Bad and Ugly”)
NUTRITIONAL SUPPLEMENTS- the best formula I have seen is called BioTears and is manufactured by Biosyntrx (www.biosyntrx.com). This formula contains all the necessary nutrients to treat dry eye conditions and usually works within 30 days. It is available through eyecare professionals or on their web site.