Dry Eyes or Dry Eye Syndrome is one of the most frequent reasons people seek eye care. Dry Eyes can have a significant impact on our daily activities including reading, driving, working and even watching television. When most people think about having dry eyes, they mainly think about the common symptoms that cause discomfort such as dryness, grittiness or burning and do not even realize that in order to have normal vision, it is critical to have a sufficient quantity of healthy tears on the surface of the eye at all times.
It is estimated that in the United States alone, 20-30 million people have mild symptoms of dry eye and another 6 million women and 3 million men have moderate or severe symptoms of dry eye.
Understanding Tears and the Tear Film
The normal tear film is made up of three distinct layers. The innermost layer called the mucous layer, directly coats the eye and helps the tear film “stick” to the eye. The mucous layer is produced by Goblet cells in the conjunctiva or “skin of the eye”. The middle layer, called the aqueous layer, is composed primarily of saline and electrolytes, and brings moisture and oxygen to the cornea. The Lacrimal Gland produces the aqueous layer, which is located under the outer portion of your upper eyelid. The outermost layer of the tear film is called the lipid layer, and it is responsible for preventing the tear film from evaporating. The tiny tubular glands in your eyelids produce the lipid layer. All three layers are critical in maintaining a normal tear film. If any of the three layers of the tear film are deficient you may suffer the symptoms of dry eyes.
Dry Eye is an eye condition in which there is a deficiency of the tear film that is due to either an inadequate production of one’s own natural tears or an excessive evaporation of tears. Whether you suffer from inadequate production of tears or excessive evaporation of tears, or both, you may experience a decrease in the quantity and quality of your tear film resulting in the surface of the eye being affected.
Inadequate Tear Production
There are many potential reasons that you may not produce an adequate quantity of tears. A number of systemic conditions such as Sjorgren’s Syndrome or autoimmune connective tissue diseases such as Rheumatoid Arthritis and Lupus Erythematosis may decrease the quantity of tears that you produce. Patients with Sjorgren’s Syndrome may experience dry eyes as well as a dry mouth and arthritis.
Inflammation of the Lacrimal Gland will also cause patients to produce too few tears to maintain a normal and healthy tear film. Other factors that can cause the Lacrimal Gland to produce an inadequate amount of your own natural tears include long term contact lens wear, past eye infections, certain allergies and even vitamin deficiencies.
Excessive Evaporation of Tears
There are a number of factors that can cause an excessive evaporation of your tears. These can include environmental factors such as being exposed to forced hot air heat at home or at work, dry climates in general, air travel, reduced blinking from contact lens wear, reduced blinking from looking at a computer screen or reading for long periods of time, air pollution or even just blowing your hair dry.
Your tears may evaporate too quickly if you suffer from low-grade eyelid inflammation, called Blepharitis. Within your eyelids are tiny tubular glands called Meibomian Glands. Any inflammation of the eyelids, such as from Blepharitis, or a condition called Ocular Rosacea (http://www.emedicine.com/OPH/topic115.htm)
can cause the Meibomian Glands to stop secreting their oily film. This oily film is required as an outer layer of the tear film to prevent evaporation. Without the oily layer being present, it is very likely that you will experience a rapid evaporation of tears and symptoms of Dry Eyes.
This is an especially common problem for perimenopausal women, as it is believed that 75% of women in this age group have some presence of facial rosacea. This along with the general hormonal changes occurring during this time, make perimenopausal women particularly susceptible to dry eyes. (http://www.agingeye.net/dryeyes/dryeyesinformation.php).
Finally, your tear film may evaporate too quickly if the tears are not properly spread and replenished over the surface of the eye because of poor eyelid movement. This may be due to a number of factors including:
- Improper or incomplete closure of your eyes during sleep
- Eye “bulging” conditions that may be related to thyroid problems
- Loss of tone or shape of the eyelids so that they turn in or turn out, called entropion and ectropion.
The Eye Center is conveniently located for patients suffering from dry eyes or dry eye syndrome or needing an eye examination for dry eye from Denver, Aurora, Arvada, Wheat Ridge, Westminster, Evergreen, Conifer, Bailey, Pine, Englewood, Littleton, Sheridan, Cherry Hills Village, Northglenn, Broomfield and Greenwood Village. If you, a family member or friend, would like to schedule a dry eye consultation, please call The Eye Center in Denver, Colorado at 303-777-5455