What Causes Dry Eyes?
Dry Eye Syndrome is a condition in which the normal tear film on the surface of the eye is reduced. The tear film is made up of three layers: a bottom mucous layer, a middle liquid or water layer, and a outer lipid or oily layer. You must have the proper amount of each of the layers in order for the surface of your eye to be healthy.
The two most common types or causes for dry eyes are:
Evaporative Dry Eye
In this dry eye condition, the outer lipid layer which protects the tear film is diminished and this allows the liquid layer to evaporate from the eye. The lipid layer is produced by the Meibomian glands located in the upper and lower eyelids. Meibomian Gland Dysfunction may account for 75% of dry eyes.
Decreased Secretion of the Liquid Layer
The glands that secrete the liquid portion of the tear film fail to produce enough of its liquid for a normal tear film.
Other Factors Related to Dry Eyes
When your eyes are dry, the cells on the surface of the eye especially on the cornea are affected. They depend on the tear film to help maintain their health. The eyes become inflamed and the cells can actually degenerate leading to more inflammation. The inflammation causes the eye condition to worsen over time.
Working or living in a dry environment contributes to dry eyes as an example: air conditioning, ceiling fans, and arid climates.
Arthritis, lupus, scleroderma, and Sjögren’s Syndrome are associated with dry eye syndrome.
Allergy medications, blood pressure medications, and diuretic medications contribute to dry eyes.
Lasik and Other Corneal Surgeries
Corneal surgeries can decrease sensation on the surface of the eye and is also associated with decreased blinking.
Diets low in omega-3 fatty acids, other anti-inflammatory foods, and low fluid intake can contribute to dry eyes.
Starring at a computer, TV, reading, sewing, and driving can lead to decreased blinking and dry eyes.
What Does Menopause Have to Do with Dry Eyes
There are testosterone and estrogen receptors on the surface of the eye and Meibomian glands. There is an association between the normal production of the components of the tear film and these hormones.
In the years before menopause increased estrogen levels stimulate more tear production and increased testosterone decreased tear production.
After menopause, there is a reversal in how the hormones affect the eye. Increased estrogen causes a decrease in tear production and increased testosterone increases tear production.
There is still a significant amount of information that we need to know about the relationship between hormone levels and dry eyes. Systemic hormone or estrogen replacement does not seem to help with dry eyes. Twice as many women as men have dry eyes. Menopause is a major contributor to the development of dry eyes. As we gain more information, we will be able to better treat the symptoms and causes of dry eyes.