Dry Eye - San Antonio Eye & Face Institute

What is Dry Eye?

Dry Eye or Dry Eye Syndrome occurs when your tears aren’t able to provide adequate moisture for your eyes. Tears can be inadequate for multiple reasons. In some cases, the lacrimal gland does not produce enough of the water component of the tear film. In other cases, the tear film is evaporating to quickly due to an inadequate oil layer of the tear film.

Individuals who have an underlying rheumatologic or auto-immune condition like rheumatoid arthritis or Sjogren’s syndrome are at risk of underproducing the water layer of the tear film. The is called aqueous deficiency dry eye. Some medications can lead to aqueous deficiency dry eye as a side effect.

In others, the meibomian glands are plugged. Meibomian glands are present in the eyelids and produce an oil that is a part of the tear film. This oil floats to the surface of the tear film and slows evaporation. If the meibomian glands are plugged, the water layer of the tear film evaporates too quickly. This is called evaporative dry eye.

What are Symptoms of Dry Eye?

Dry eyes can be very uncomfortable. Common signs of dry eye include:

stinging or burning in your eye
sharp, stabbing pain that lasts seconds
gritty or scratchy eyes
feeling like there is something in your eye (foreign body sensation)
red eyes
blurry vision
tearing
glare or sensitivity to light

You may experience dry eyes in certain situations, such as on an airplane where the eye is dry, in an air-conditioned room or vehicle, while reading, or after looking at a computer screen for extended periods of time.

#1 Environmental Factor for Dry Eye

In San Antonio, the weather is frequently hot. Ceiling fan use is very common as a way to keep cool and reduce energy costs. The circulating air from ceiling fans cause the tear film to evaporate more quickly leading to many of the symptoms listed above. If your read or watch TV under a ceiling fan, this can exacerbate the problem, because the number of times you blink per minute (the blink rate) decreases when performing such activities. The combination of a reduced blink rate and ceiling fan use can quickly lead to severe symptoms of Dry Eye.

Other Risk Factors for Dry Eye

Age greater than 65
Female Gender – can be caused by hormonal changes during pregnancy, as a side effect of birth control medicines,
Medications
Health Conditions
Contact Lens Use
Environmental Irritants
You had LASIK Surgery

How Does Aging Affect Dye Eye?

Most people will experience dry eye as they age. It’s just a part of your eyes getting older. The lacrimal glands (which produce the water part of the tear film) and the meibomian glands (which produce the oil part of the tear film) simply don’t work as well over time. Inflammation in the body can increase as we age. Inflammation can affect the lacrimal gland and decrease production of the water part of the tear film.

Other health conditions like diabetes, thyroid disease, and rheumatoid arthritis become more common as we age. The diseases themselves and the medicines used to treat them can cause dry eye. Finally, the eyelids can lose collagen and elastin with age. This can cause them to droop and sag. When the lower eyelids droop, they can flop away from the eye (a condition called ectropion) causing tears to run off the eye and down the cheek.

Dry eye is more common as we age, but you don’t need to suffer. There are treatments for the different underlying causes of dry eye.

How Does Gender Affect Dry Eye?

Changes in hormone levels can affect dry eye. During pregnancy, hormone levels change and can cause dry eye. After pregnancy, hormone levels may change again and symptoms may improve. The use of birth control medications can also alter hormone levels leading to dry eye. After menopause, whether it occurs naturally with age or as a consequence of surgery, hormone levels change. Mucus membranes may have lower moisture levels. Because the eye is essentially coated with a mucus membrane, they can become dry.

How do Medications Affect Dry Eye?

If you have allergies and take antihistamines, high blood pressure and take blood pressure medications or anxiety/depression and take medicines for anxiety/depression, your eyes can become drier as a side effect of the medications. Sometimes treatment can be provided to your eye to improve your symptoms. Occasionally, the medication may need to be changed or stopped to improve the dry eye symptoms.

Do Contact Lenses Cause Dry Eye?

Contacts do not cause dry eye, but they can be uncomfortable to wear if you have Dry Eye. You may be able to tolerate them for short periods of time, but extended wear can cause all the symptoms of Dry Eye. You may need to experiment with different brands of contacts and use contact lens rewetting drops to keep your eyes comfortable. Many have found improved comfort by switching to daily use contact lenses.

What Environmental Factors Affect Dry Eye?

As mentioned above, the use of ceiling fans is an underappreciated contributor to Dry Eye. If you’re around smoke, wind, dust, or dry conditions, you may also develop Dry Eye. The home environment can usually be tightly controlled and regulated, but the work environment may be more difficult to control. If you work in a bar, you may be exposed to smoke from people smoking cigarettes, a lifeguard may deal with windy, dusty conditions, and construction worker may work in a hot, dry environment. Any of these scenarios can lead to Dry Eye.

Many jobs now require the use or computers. The computer and its blue light emitting screening does not directly cause Dry Eye. Your blink rate (the number of times you blink per minute) goes down when you stare at a computer screen or cell phone screen. This can cause all of the symptoms of Dry Eye.

Does LASIK Surgery Cause Dry Eye?

Yes, it does. When LASIK surgery if performed, a flap is cut on the surface of the eye (the cornea). The cornea has a lot of small nerves that provide feedback to the lacrimal gland letting the gland know when the surface of the eye is dry. These nerves are cut during LASIK surgery and do not regenerate. The natural feedback loop that the eyes have to keep themselves moist is disrupted by LASIK surgery.

Immediately after LASIK surgery, the eyes are usually very dry for this reason. Over time, symptoms typically improve, but some continue to suffer from chronic Dry Eye. Having Dry Eye is sometimes considered a reason to not undergo LASIK surgery. Believe it or not, there have been some rare cases of individuals committing suicide due to severe Dry Eye symptoms after LASIK surgery.

How is Dry Eye Diagnosed?

Dry Eye can be diagnosed with a slit lamp examination. Your doctor will put drops in your eyes to examine the surface of the eye and your eyelids with a slit lamp microscope. The Schirmer’s test uses a small strip of paper with a ruler to measure your tear production. This test is used less commonly today due to inaccurate results. Your tear film may dry rapidly when you stare. This is called a decreased tear break up time (TBUT). These findings along with your medical history and list of medicines can be used to make a diagnosis of Dry Eye.

There are also newer tests that look for specific indicators or markers of dry eye. These test may be overkill as the diagnosis is usually easy to make with the slit lamp. The costs of these tests may also be a waste and could be better applied to the treatment of the condition.