The Clear View: Is it Dry Eye Disease or Allergies?
The goal of optometrists is to give patients clear, single, comfortable vision. Right now, let’s talk about eye comfort.
The simple definition of Dry Eye Disease (DED) is a loss of tear film volume. The tear film breaks down and causes discomfort in the eyes. This is important because tears are the first surface that focuses the light coming into the eye. Tears protect and nourish the cornea and ocular surface. DED can have many causes and is quite common. According to the Tear Film and Ocular Surface Society (TFOS), DED affects 344 million people worldwide and 30 million in the United States. TFOS meets every ten years to update eye care professionals on the latest findings on DED and suggest diagnostic and treatment strategies.
DED is a chronic and complex disease. It will not go away and must be managed like any other disease. Many patients come in year after year complaining that their eyes tear yet do not follow their doctor’s suggested treatment, assuming that the dry eye will just go away.
It sounds impossible but one of the hallmarks of dry eye disease is tearing. Many patients ask how their eyes can be so wet if they are dry! The answer is that the body attempts to increase the tear volume by creating reflex tears. But the body cannot control the volume of the reflex tears and makes more than is needed. The excess reflex tears roll down the cheeks.
Not only is DED chronic and complex, but it can be confused with other ocular conditions that have totally different causes and treatments. One of the most confusing includes ocular allergies: these occur as a reaction to pollen emitted every spring from trees and grass and every fall from ragweed (pictured here). Eye care providers must take extra time to differentiate between seasonal allergies and dry eye. As you can see from the table below, some symptoms are very similar. This table is for information only, it is not intended for self-diagnosis or treatment. Your eye care provider can determine the best treatment for you.
DRY EYE DISEASE |
ALLERGIES |
Grittiness |
Itching eyes |
Eyes feel tired, redness |
Puffiness, redness |
Sporadic tearing |
Constant tearing |
Flaky lid crusting |
Crusting with mucous |
Thankfully, seasonal allergies last only a short time. Chronic allergies, to pets or food, for example, can produce ocular symptoms too. In this case, some optometrists offer allergy testing or will refer you to an allergist for testing. The doctor will discuss treatment if there are any positive test results. Treatment may include some of the many effective, inexpensive, over-the-counter options or may suggest a prescription. Allergies are one of the many pieces of the dry eye puzzle. Together you and your optometrist can work toward solving it so that your eyes are more comfortable.
Thank you Lisa. This is a very interesting article.