Have you noticed your eyes are sometimes dry and uncomfortable? Possibly more irritated than usual? If so, you’re not alone. Dry eye disease can appear suddenly, and its symptoms are often ambiguous.
You think to yourself, “What’s different? Perhaps I need to drink more water. Or maybe I need to change my furnace filters. Have I been on my computer too much? Are my contact lenses failing me?”. It can be hard to pinpoint why suddenly your eyes feel dry, irritated and uncomfortable.
Or the inverse: your eyes have bouts of excessive tearing for no apparent reason. What’s going on?
These are all real questions and concerns I have received from my patients.
Let’s discuss dry eye disease in detail: its causes, symptoms, and what can be done to alleviate this condition that’s increasing in record numbers across North America.
What is Dry Eye?
Dry eye, also known as keratoconjunctivitis sicca, is a condition that occurs when our eyes don’t receive the natural tear moisture they require. When this happens, the result is dry, uncomfortable, and gritty-feeling eyes.
And unfortunately, it’s becoming more and more prevalent. In fact, a recent study conducted in Ontario shows that upwards of 6 million Canadians now show symptoms of dry eye.
How Does Dry Eye Develop? A Closer Look at Our Tears
In order to function optimally, our eyes require moisture at all times. Tears, produced by the lacrimal glands, protect and nourish the front surface of our eye, keeping them lubricated every time we blink.
Our tears are made up of 3 layered elements: water, oil, and mucus, called the tear film. Each element works closely together and has a very important and specific purpose: the water layer nourishes, the oil layer helps prevent quick evaporation of the water layer, and the mucus layer spreads tears evenly over the eye surface.
Dry eye can develop from:
- An imbalance in the tear film. Meaning, our tears are producing inadequate amounts and/or the improper balance of oil, water, or mucus required. The result is poor quality tears that are unable to adequately lubricate the eye.
- Low tear production. For reasons outlined below, if our lacrimal glands aren’t producing enough tears, our eyes cannot retain moisture and dry eye can quickly set in.
Symptoms of Dry Eye: Is It Just How It Sounds?
It is true that the most common symptom of dry eye is just that: dry eyes. But it can also include:
- Red, irritated eyes
- Tired, sore eyes
- Blurred vision
- Sensitivity to light
However, along with obvious dry feeling eyes, my patients are continuously surprised to hear about these additional symptoms one wouldn’t normally associate with dry eye:
When the eyes are undergoing feelings of discomfort or trauma, their natural reflex is to protect and comfort themselves. The lacrimal glands are prompted to make an excess of tears, called reflex tearing. As counterintuitive as this may seem, excessive tears are an extremely common symptom of dry eye.
Foreign Body Sensation
When cells on the surface of the eye dry out, they may create micro-abrasions causing your eyes to feel sandy or like there’s something in it you just can’t see or remove. This uncomfortable feeling of having something stuck in your eye is another sign of dry eye disease.
When the eyes are dry, they can become red and slightly inflamed. The instinct to rub or try to scratch them is normal. Many patients mistake itchy eyes for allergies – when in fact it is another popular symptom of dry eye.
Admittedly more of a cause than a symptom, lagophthalmos is an occasional cause of dry eye. Characterized as a group of eyelid abnormalities, lagophthalmos occurs when eyelids don’t close all the way, either due to another condition or genetics. Ranging from slight to severe, most patients don’t know they even have it.
So Why Are Our Tears Forsaking Us? Causes of Dry Eye
Now we know the root medical cause of dry eye: problems with our tears. And also the symptoms, some obvious, some not.
But what factors cause poor quality tears and an insufficient amount of them? The causes are many and they differ greatly.
Meibomian Gland Dysfunction (MGD)
Meibomian gland dysfunction (MGD) is now known as the leading cause of dry eye. Meibomian glands, located in the upper and lower eyelids, secrete the oil that makes up one layer of our tear film. As stated previously, this oil keeps the water in our tears from evaporating too quickly, keeping needed moisture in our eyes.
When these glands become blocked or cease to function, meibomian gland dysfunction (MGD) is the result.
Aqueous Tear Deficient Dry Eye (ATDDE)
ATDDE occurs when the lacrimal glands, the glands located in the upper eyelid which produce our water, or aqueous, tear film layer, stop producing an adequate amount of water needed to nourish the eye. This condition is often related to various medical conditions, namely hepatitis and Sjogren’s Syndrome.
Digital Eye Strain
Digital Eye Strain, or Computer Vision Syndrome, is an unfortunate by-product of the digital age in which we live. With prolonged computer or screen use, comes less blinking, resulting in blurred vision, eyestrain, headaches, and dry eye.
When we age, tear production decreases. As a result, dry eye is shown to becoming increasingly common in people over the age of 50 and notably in menopausal women.
Many prescription and nonprescription medicines can increase the symptoms of dry eye. These include antihistamines, antidepressants, blood pressure medications, birth control pills, and more.
Both indoor factors – like forced-air heating and cooling systems, and ceiling fans, as well as outdoor aspects like dry climates, allergies or smoky/windy conditions, can lead to dry eye.
Some systemic conditions, such as diabetes and lupus have been linked to dry eye. Similarly, Bell’s Palsy and other forms of facial paralysis that prevent the eye from closing properly may also lead to dry eye.
So What Can We Do? How To Manage Dry Eye
Unfortunately, dry eye syndrome is usually chronic, which means it is not easily curable. However, there are some management strategies that have proven helpful. Things like artificial tears, medicated eye drops and advances in supplements and nutrition are coming a long way in the fight against dry eye.
There are also treatments like LipiFlow, iLux®, and Intense Pulsed Light, dry eye therapy treatments that use heat, light, and massage to clear blockages in the oil-producing meibomian glands. The oil our tears need to retain water.
I’m Keeping Dry Eye on my Radar
As an optometrist, I’m keeping an eye out for emerging studies in the field of dry eye and new management strategies that emerge.
Especially since more and more patients, day after day, are coming into my clinic with symptoms and coming out with a dry eye diagnosis.