It’s not merely uncomfortable: the condition can affect your vision. But you can do something about it
By Wendy Haaf
Several years ago, during a routine eye exam, Helen Bratzel of Windsor, ON, was informed that she had dry eye. However, because her eyes didn’t feel irritated, gritty, or dry (in fact, they were often watery) and her optometrist at the time didn’t elaborate, “I didn’t pay much attention,” she recalls.
It wasn’t until she became frustrated trying to get her vision corrected by another eye-care professional that she learned that the problem wasn’t her glasses; it was the protective film of tears covering her eyes.
“I kept going back in and trying to get my prescription corrected,” she says. “I didn’t really understand that the layer of tears over your eyeball is part of how you see; because I had dry eye, I had a prescription that looked like it should work but didn’t.”
Like Bratzel, up to 30 per cent of Canadians have dry eye (many of them over 55, since the condition becomes more common with age) and may not recognize the symptoms or may be misdiagnosed with something else, such as pink eye. And the symptoms are no joke—research suggests that when it comes to impairing quality of life, productivity, and social and physical function, moderate dry eye is on par with moderate angina, and the severe form is more disabling than hip fractures.
A Question of Quantity or Quality
Essentially, dry eye is a problem with the film of tears that protects the cornea of the eye from the outside world. Tears aren’t just plain old salt water; they’re actually composed of a mixture of three things: aqueous humour (a watery fluid similar to blood plasma), mucins (protein components of mucus), and lipids (oils).
If something happens to upset the balance of these substances, the resulting symptoms can cause a variety of problems, ranging from chronic discomfort to (uncommonly) potentially vision-threatening damage. For instance, a shortage of oil—which normally acts as a sort of swimming pool cover, keeping water in—can allow tears to evaporate too quickly.
“That exposes the cornea to the air, so when the wind blows by and touches it, your eye thinks there’s something in it and produces really watery tears to try to flush it out,” explains Michael Nelson, an optometrist with Waverley Eye Centre and EyeGym Canada in Winnipeg and vice-president of the Canadian Association of Optometrists. “A common scenario is that people will be going for a walk or riding in the car with the defroster or the air conditioning running and their eyes will start to water.” (This is sometimes mistaken for an allergic reaction, and in severe cases, can interfere with activities such as driving, as Dr. Melissa Yuan-Innes describes in her book, The Emergency Doctor’s Guide to Healing Dry Eyes, Windtree Press, 2017.)
If the tear volume is too low, either due to rapid evaporation or underproduction, or if the composition isn’t just right, it can cause “blurry, fluctuating vision, because the tear film is integral to creating a clear image,” Nelson says.
“Some people tell me, ‘I have to blink a lot to clear up my vision,’” adds Dr. Rookaya Mather, an ophthalmologist with the Ivey Eye Institute’s multidisciplinary Dry Eye Clinic at St. Joseph’s Health Care London (ON) and an associate professor with Western University’s Schulich School of Medicine & Dentistry. “That’s because the tear film isn’t stable—blinking stabilizes it temporarily.”
Very dry air, contact lens use, and long uninterrupted bouts of reading, computer use, and other visual tasks can also contribute to tear loss. For example, dry eye is frequently the culprit when a contact lens wearer can’t tolerate lenses for more than three or four hours at a stretch. “The contact lens is kind of absorbing their tears and leaving their eyes dry,” Mather says.
Even people with normal, healthy tears can experience dry eye symptoms after long stretches behind the wheel or in front of the tablet, cellphone, or computer. “If you’re having coffee with someone, you normally blink about 15 times in a minute,” Nelson explains, but when you’re doing a visual task, such as working at the computer, “people tend to stare, and blink only about four times a minute, so that will contribute to dry eye, as well.”
“Not infrequently, we see young people who have the symptoms of dry eye, not because they’re failing to produce enough tears, but because they’re engaged in activities that increase tear evaporation,” Mather notes.
More obvious symptoms of dry eye include redness, irritation, and the sensation of a foreign body in the eye—all of which, like the symptoms above, can sabotage quality of life. “Imagine if every moment of every day, and not just when you’re awake, your eyes always had the gritty feeling you get when you’ve taken a red-eye flight and haven’t slept,” Mather says. Over time, this can interfere with someone’s enjoyment of life and even lead to depression and anxiety, she adds. The condition can also pose a financial burden, since treatments typically aren’t covered by provincial health plans.
As We Get Older…
For a variety of reasons, dry eye becomes increasingly common after the half-century mark.
For one thing, “tear production drops with age,” Mather explains. Similarly, oil-producing glands located at the base of the eyelashes (called meibomian glands) “stop functioning, as well,” she adds.
As we get older, we’re also more likely to be taking medications, some of which (antihistamines, diuretics, beta blockers, and tricyclic antidepressants, to name just a few) can interfere with tear output.
In menopausal women, hormonal changes can also contribute. “At menopause, women have a fall in hormone levels, and it’s not just estrogen, but also testosterone,” Mather explains, “and there’s evidence to suggest that testosterone is required for normal tear production. And a woman would have a more noticeable effect than a man, which is why it’s a more common condition in menopausal females,” she says.
With the passing birthdays, we’re also more apt to have needed some sort of eye surgery, which is another risk factor. “Cataract surgery, laser vision correction, glaucoma surgery, and retinal surgery all change the tear film dynamics,” a situation that is typically—but nowhere near always—short-lived, Mather says. “Sometimes, if you had dry eye before, surgery just puts you over the edge. So while you weren’t aware of it before and it didn’t affect your life, once you have cataract surgery, you notice it every day.”
In some cases, inflammation in the tear-producing glands plays a role. For example, in certain autoimmune conditions, such as Sjögren’s syndrome (two prominent symptoms of which are dry eye and dry mouth), lupus, and rheumatoid arthritis, certain immune cells can attack and damage the lacrimal (tear) glands. And finally, for reasons that aren’t fully understood, there may be inflammation, dysfunction, or blockage in the meibomian glands.
While there’s no single test to diagnose dry eye, your eye-care professional can look for signs of the condition as part of a routine eye exam by using a microscope called a slit-lamp to examine the surface of the eye, or by instilling a tear-highlighting dye, “which shows cells that are damaged or irritated on the surface of the eye and also shows us how quickly the tears evaporate,” Nelson says.
If you suspect you have dry eye, you can fill out the following questionnaire and take it to your optometrist: dryeyezone.com/documents/osdi.pdf. In addition, the Sjögren’s Society of Canada website has some good information on dry eye and more specialized tests: sjogrenscanada.org.
While there’s no cure for dry eye, a number of treatments can help. In some cases, the consistent use of a number of simple strategies may be sufficient to improve symptoms, starting with regular use of lubricating artificial tears available over the counter.
“The drops mix with your tears and help stabilize them,” Nelson says.
“The key is to be proactive and not reactive,” Mather stresses. “You need to use drops before your eyes burn, or get gritty and sandy, and before you have to put the book down or turn off the computer.”
Your optometrist or ophthalmologist can recommend a brand that’s best-suited to whether your problem is primarily a lack of tears or of oil, but in general, “it’s a matter of staying away from drops that promise to take the redness out or that say they’re good for allergies,” Mather says. “Those contain ingredients that shrink blood vessels, the long-term use of which isn’t healthy, and drops that are meant to reduce itching contain antihistamines, which dry you out.” If you need drops more than four to six times a day, choose a brand that’s labelled “preservative-free,” since used too frequently, those containing preservatives can create a vicious cycle of worsening irritation.
Applying warm compresses to the eye once or twice a day and taking a 2,000 mg omega-3 (alone, not in combination with omega-6 or 9) supplement each day may also help ease symptoms.
“The compresses help melt some of the oil in the meibomian glands and allow it to flow better,” Mather says. “And the omega-3s are anti-inflammatory, so they get incorporated into the oil in the tear film and make it less inflammatory,” she adds. “We usually recommend the fish-oil type because it’s more readily used in your body than flaxseed.”
It’s also a good idea to take regular breaks (ideally, at least every 20 minutes) during computer work and other visual tasks by looking up 20 feet into the distance for 20 seconds. Wearing wraparound sunglasses outdoors can provide protection against drying wind, as well.
In more complicated cases, or those that don’t respond sufficiently to this regimen, other treatments may be recommended, including prescription anti-inflammatory drops, and even tiny plugs to partially dam up the “drains” in the eye so tears stay on the surface longer.
Because the optometrist who initially diagnosed Helen Bratzel with dry eye didn’t explain the problem or how to properly use the drops he gave her, “I probably used them a couple of times and thought, Well, that didn’t make any difference,” and stuck the sample in a drawer, she says. Now, however, putting the drops in is part of her morning routine. “I put them in right after I brush my teeth.”
While it’s too soon to say whether the omega-3 supplement she recently added to her regimen is helping, “the drops definitely make a difference,” she says.