Dry Eye Diagnosis and Tear Film Deficiency
Dry Eyes or Dry Eye Syndrome is a very common eye condition that affects millions of Americans. It is estimated that dry eyes affect up to 11% of people aged 30 to 60 years of age and 15% of those 65 years of age or older according to the International Task Force assembled by the Johns Hopkins University-Wilmer Eye Institute. They also concluded that as many as 12 million Americans have moderate to severe dry eyes and that this number is likely to increase with the aging populations resulting in a significant decrease in the quality of life.
Simply, dry eyes are caused by either a deficiency in the quantity or the quality of the tears or tear film. Fortunately, today eye care patients can benefit from better diagnostic procedures for dry eyes as well as more advanced dry eye treatments from eye physicians.
Symptoms of Dry Eye Syndrome
The most common symptoms of dry eyes include dryness, itching, burning, irritation or grittiness, redness, blurry vision that gets clearer as you blink, light sensitivity and contrary to common sense…excessive tearing. These symptoms typically increase during vision related activities such as reading, computer use, night driving, or watching television. They may also increase in response to environmental conditions such as wind, low humidity, airplane travel, or smoking or being in a smokey environment. Many of these symptoms of dry eyes may also be found in other eye conditions, making careful diagnosis especially important.
What are the causes of dry eye syndrome?
Environment: Sunny, dry, or windy weather, heaters, air conditioners, and arid high altitudes increase the evaporation of tears from the surface of your eyes. You may experience dry eye symptoms while viewing television, computer screens, while reading or doing anything that reduces your rate of blinking.
Aging: During the normal aging process, our bodies and our eyes produce gradually less and less oil. This reduction in oil in the tear film results in quicker evaporation leading to the formation of dry spots on our eyes.
Contact Lenses: Contact Lenses are subject to dehydration or loss of their water content. As they dehydrate, they can absorb the tear film causing dry eye symptoms. In some cases, the continued drying of the contact lens surface causes it to become deposited with protein making the lenses even more uncomfortable than the dryness alone.
Medical Conditions: Women experiencing hormonal changes, those patients suffering from thyroid disease, rheumatoid arthritis, psoriasis, eczema, acne rosacea and a number of other systemic conditions may experience dry eye syndrome.
Medications: Diuretics taken for high blood pressure, allergy medication, antihistamines, acne medications and many others may all produce dry eye symptoms.
How do I know if I have dry eye syndrome?
Common symptoms of dry eyes may include dryness, burning and stinging. A foreign body sensation, like sand being in the eye, is often encountered. Your vision can be blurred. Reflex tearing may actually be stimulated resulting in excessively watery eyes. Some patients may experience redness of their eyes. It is not uncommon for your eyes to lose their normal luster and clearness when looking in the mirror.
To help you determine whether you suffer from one or more symptoms of dry eyes you can take a brief self assessment quiz for dry eyes.
Diagnosis of Dry Eyes
There are several clinical examination methods that are useful for helping to diagnose and determine the severity of dry eyes. Your eye doctor may use all or some of the following tests to help make the diagnosis:
Tear Break Up Time is a measurement made by observing the rate at which the tear film begins to evaporate and indicates the overall stability of the tear film.
Tear Staining is a method of using special dyes to help highlight problems with the surface of the eye and the tear film quality. By placing these eye drops in the tear film the severity of the dryness can more easily be recognized.
Tear Film Height is a measurement made with the slit lamp biomicroscope to evaluate tear volume
A Schirmer Test may be performed by placing a small piece of special paper inside your lower eyelid to measure tear production.
From these tests an assessment can be made as to whether the dry eye condition is mild, moderate or severe and thus what type of treatment options may be best.