Dry Eye Syndrome
Did you know: At age 65 the eye produces approximately 60% fewer tears than it did at age 18. Did you ever wonder why your eyes are covered with tears? It s because the delicate tissue on the surface of the eye the cornea has no blood supply - it has a tear supply instead. Rather than getting important things like oxygen and electrolytes from the blood your eyes get these substances from the watery layer of your tears. The tear layer acts as a barrier to infection keeps the surface of the eye clear and provides the necessary nutrients to the cornea.
Dry eye syndrome (D.E.S.) is caused by a failure to produce the necessary quality or quantity of tears to protect and preserve the ocular surface of the eyes. Those with D.E.S. do not have a sufficient amount of tears to adequately bathe the eyes and therefore often complain of irritated scratchy stingy and/or red eyes. In severe cases many even suffer from decreased visual acuity. Some patients will also complain of watery eyes which can be the result of the eye s attempt to replenish its tear supply. Insufficient lubrication can eventually lead to a compromise in the health and integrity of the corneal surface reducing its ability to act as a barrier to infection.
D.E.S. is a common condition among:
- people over the age of 65
- computer users
- contact lens wearers
- those who work in dry and/or dusty environments
- those exposed to excessive air conditioning
- those with allergies to dust or pollen
- arthritis sufferers
- women who are pregnant, nursing,post-menopausal
- people taking certain medications such as anti-depressants,oral contraceptives,antihistamines,acne medications,blood pressure pills
Did you know:
At age 65,the eye produces approximately 60% fewer tears than it did at age 18.
The Anatomy of Dry Eye
Three thin layers make up the healthy tear film that coats and protects the eye.
- The outer or lipid layer provides an oil-based surface that slows down the evaporation of tears. If this layer did not exist tears would evaporate 10 to 20 times faster than they do.
- The middle or aqueous layer includes salt and protein in a base that is 98% water.
- The inner mucin layer coats the surface of the eye allowing the other layers to form a film. Without this layer the tears would bead up much like rain does on a waxed car
When tears lack the important components shown above or when too few tears are produced the tear film can break down. This breakdown produces dry spots on the cornea causing the symptoms associated with dry eye.
Surprisingly dry eye syndrome does not always cause dry eyes. Burning or itching eyes a gritty feeling in the eyes presence of stringy mucus discharge excessive tearing and increased sensitivity to light are common symptoms of dry eyes. It is often difficult to wear contact lenses when there is a flare-up because the contact lenses absorb many of the tears leaving a diminished quantity to bathe the eyes.
How to get relief?
The tear film is essential to protect your eyes and treatment will provide more comfort. Your eyecare practitioner uses simple tests to assess the quantity and quality of the tear film. Depending on the severity of your condition tear replacement is the most commonly recommended therapy - this involves the use of lubricant eye drops. The primary goal of treatment is to keep the eye moist and comfortable and to protect the eye s delicate surface. There are many brands of artificial tears available on the market but not all are equally effective. Depending on the cause and severity of dry eye your optometrist can select the product that will most successfully relieve the problems of dry eye.
Another therapy of benefit in certain cases is the use of plugs made out of collagen for temporary use and of silicone for more permanent use that partially block the tear drainage ducts. This reduces the drainage of tears away from the eye and maximizes the time in which the tears are in contact with the eye. Some simple remedies that can help those with mild to moderate D.E.S. include:
- Stay hydrated by drinking plenty of water. This helps to keep your eyes lubricated and healthy
- Avoid drafts from heating or air conditioning vents especially in cars and airplanes
- Decrease caffeine (found in coffee pop etc.) and alcohol intake to a minimum as these products are diuretics and cause the body to expel water
- Ensure that all makeup is removed daily with makeup remover
- Avoid dusty and smoky environments
- Humidify environments whenever possible