Dry Eye Syndrome? Drops Are Not the Only Option
Dry eye symptoms can point to several different problems
Your eyes are dry, itching, burning. It seems like a pretty straightforward diagnosis: dry eye syndrome. But it’s a little more complicated than that.
Dry eye syndrome actually is an umbrella term for a number of different conditions that can diminish the quantity or quality of tears that keep the surface of our eyes adequately lubricated.
It’s a common condition. About 16.4 million Americans have been diagnosed with dry eye syndrome (keratoconjunctivitis sicca), reports the National Eye Institute (NEI), which is part of the National Institutes of Health. Age is a risk factor and dry eye is more common in people age 50 and older. Women are more likely to develop dry eyes due to hormonal changes caused by pregnancy, the use of oral contraceptives and menopause.
To diagnose dry eye syndrome, ophthalmologists examine the eyes and eyelids. Tests they can do include measuring the thickness and quality of a patient's tears and how quickly the eyes produce tears, according to the American Academy of Ophthalmology. Tears are a complex mix of oils, water, mucus and more than 1,500 proteins that protect your eyes from the environment, irritants and pathogens.
Causes of Dry Eye Syndrome
In some cases, dry eye is the result of a serious underlying condition. Autoimmune disorders, such as Sjögren’s syndrome, lupus, scleroderma and rheumatoid arthritis, as well as diabetes and thyroid disorders are associated with dry eye. In addition, rosacea, an inflammatory skin disease, and blepharitis, an inflammatory eyelid disease, can disrupt the function of the meibomian glands, which are oil glands along the edge of the eyelids.
Several kinds of medications also have been associated with dry eye syndrome. These include antihistamines, decongestants, antidepressants, hormone replacement therapy to relieve symptoms of menopause and medications for anxiety, Parkinson’s disease and high blood pressure.
“People often don’t realize dry eye is such a complex topic,” says Dr. Anat Galor, a Miami ophthalmologist and spokesperson for the American Academy of Ophthalmology. She’s author of a number of publications that focus on dry eye, ocular surface tumors and the cornea (the outermost layer of the eye).
Galor recommends an annual visit to an ophthalmologist and good hygiene. “At age 50, I think eyes should be treated like teeth,” she says. “You should clean your eyes. Use a wash cloth or medicated product to get rid of debris on the lashes and keep your eyelids clean.”
Artificial Tears and More
In general, “our meibomian glands don’t work quite as well as we age. We’re making tears but they’re not as healthy. We don’t have the therapy to change your eyes back to the eyes of a 20-year-old,” but there are treatments to ease the irritation, Galor says.
Over-the-counter artificial tears are often helpful, but make sure the product doesn’t contain the preservative benzalkonium chloride, Galor cautions.
“The majority of people who have some sense of drying will be fine with artificial tears and good hygiene,” she adds.
Limiting the amount of time you spend staring at the computer screen can also help. NEI recommends blinking repeatedly for a few seconds while working to help replenish tears and spread them more evenly across the eye. Sunglasses that block wind and dry air can also reduce symptoms, as can smoking cessation and limiting exposure to secondhand smoke.
The only prescription medications approved by the Food and Drug Administration (FDA) for treating dry eye are cyclosporine and lifitegrast. Corticosteroid eye drops also may be prescribed short term to reduce eye inflammation.
The FDA also has approved devices that heat the eyelids to stimulate glands and nerves associated with tear production.
Then there’s “punctal occlusion,” in which plugs made of silicone or collagen are inserted by an eye care professional to partially or completely plug the tear ducts at the inner corners of the eye. This keeps tears from draining from the eye. In severe cases, surgical closing of the drainage ducts by thermal punctal cautery may be used to close the tear ducts permanently, according to NEI.
What Doesn’t Work?
According to the findings of a well-controlled trial funded by the NEI, omega-3 fatty acid supplements taken orally proved no better than a placebo at relieving symptoms or signs of dry eye. The trial investigated the highest dose of omega-3 ever tested for treating the condition.
“Some people really wanted it to be a positive,” Galor says. “Many people still recommend it. But omega-3 from fish oil supplements is no better than a placebo.”
Treatments Being Developed
One important area of research that NEI is now supporting is stem cell therapy to repair the lacrimal glands, which secrete tears. Although at an early phase of development, such an approach could use a patient’s own cells to rebuild or replace lacrimal glands, according to the institute.
Other researchers have developed an implantable device that electrically stimulates the lacrimal glands to produce the tears that keep the cornea lubricated. The team has been able to fine-tune the content of the tears by stimulating other glands around the eye, producing tears that contain not only water, but lipids and mucins to more closely resemble the consistency of naturally-occurring tears.
Another group of researchers is exploring factors that influence the ability of corneal nerves to sense tear evaporation. In a healthy eye, only one-tenth of a degree of cooling from evaporation is needed to activate corneal nerves, which in turn triggers tearing, the NEI says. But with dry eye syndrome, such cooling fails to trigger a response. Scientists are working to develop topical corneal nerve stimulators to increase nerve sensitivity to drying.
And since corneal nerve number, length and function are substantially diminished in dry eye, other NEI-funded researchers are investigating ways to promote the regrowth of these nerves.