With so many potential causes of dry eye, getting a true diagnosis is not always easy. Some people who experience the telltale dryness and itching may not have dry eye disease at all. Instead they have underlying conditions, such as allergies or the autoimmune disorder Sjogren’s syndrome, for which dry eye is a symptom, or they may be taking medication for which dry eye is a side effect.
It’s important to get an accurate diagnosis because treatment usually involves a combination of prevention, figuring out what provides relief and addressing underlying conditions that could harm eye health.
“The first step is a comprehensive exam,” says Robert Latkany, M.D., a New York-based dry eye specialist and the author of The Dry Eye Remedy. Because dry eye is a symptomatic disease, this should involve taking a complete patient history and asking questions to help identify if certain situations or medicines are triggering the symptoms and to see what, if anything, helps.
Next, the provider will perform a slit lamp examination. The slit lamp a low-powered microscope that shines a beam of high-intensity light into the eye. It allows a close-up view of the entire eye structure, including a chance to screen for meibomian gland dysfunction, a common cause of dry eye that happens when the glands along the margins of both the upper and lower eyelids no longer secrete the oils needed for healthy tears.
Slit lamps also allow a provider to see if there is dandruff at the roots of the eyelashes, and to make sure the eyelids close correctly. This is important because many people who think they have dry eye actually have a condition called lagophthalmos which prevents them from fully closing their eyes when they blink or when they sleep.
Most cases of dry eye can be diagnosed through slit lamp examination. Additional tests can measure tear production, the amount of time it takes tears to evaporate and check for proteins and enzymes that play a role in eye health. In addition, if a provider suspects an underlying health condition could be causing dry eye, he or she will order additional tests to try to get to the root of the problem.
“All this takes time,” says Dr. Latkany, who points out that by the time most people see a dry eye specialist, they have typically seen several providers and tried a range of products without success. “Sometimes it’s not so easy to figure out what helps people, but it can be very rewarding to see them get their lives back after years of suffering from dry eye.”