Dry eye disease is a complex condition associated with a wide variety of individual, environmental and disease-related factors affecting the tears and ocular surface resulting in symptoms of discomfort, visual disturbance and tear film instability, with potential damage to the ocular surface. It is accompanied by increased osmolarity of the tear film and inflammation of the ocular surface. Some people may present with many symptoms or only a few, and often the signs and symptoms described are contradictory. One may present with inflammation and redness but experience no discomfort while some aren’t able to articulate their problem effectively; they merely know that they have ocular discomfort.
When people don’t produce enough tears or the right quality of tears to keep their eyes healthy and comfortable, the condition is known as dry eye. The tear film consists of three layers (oil, water, and mucus) each serving its own purpose. The outermost surface of the tear film is oil produced by the meibomian glands, smoothing the tear surface and reducing evaporation of tears. The middle watery layer makes up most of the “tears” which consists of a variety of proteins and fluids. This layer, produced by the lacrimal glands in the eyelids, serves to cleanse the eye and wash away foreign particles or irritants. The innermost layer is conjunctiva secreted mucus that allows “tears” to spread evenly across the surface of the eye and helps the eye remain moist. Without mucus, tears would not stick to the eye.
Normally, the eye constantly bathes itself in tears by producing tears at a slow and steady rate, providing a comfortable environment for the eye. Under certain circumstances, the eye will produce a lot of tears in response to irritation or emotion, such as when a foreign body or dryness irritates the eye, or when a person cries. Eye irritation prompts the lacrimal gland that makes tears to release a large volume of tears, overwhelming the tear drainage system resulting in an overflow from your eye.
Causes
Conditions that affect the lacrimal gland or its ducts — including autoimmune diseases like lupus and rheumatoid arthritis — lead to decreased tear secretion and dry eye.
Tear secretion also may be reduced by certain conditions that decrease corneal sensation. Diseases such as diabetes and herpes zoster are associated with decreased corneal sensation. So is long-term contact lens wear and surgery that involves making incisions in or removing tissue from the cornea (such as LASIK).
A wide variety of common medications, both prescription and over-the-counter, can cause dry eye by reducing tear secretion. Therefore, it is important to tell your eye doctor the names of all the medications you are taking, especially if you are using any of the following:
- Diuretics for high blood pressure;
- Beta-blockers for heart or high blood pressure;
- Antihistamines for allergies;
- Sleeping pills;
- Anti-anxiety medications;
- Pain relievers.
Since these medications are often necessary, the dry eye condition may have to be tolerated or treated with eyedrops called artificial tears.
Anyone can experience dry eye, though it is more common among women, particularly after menopause. Women who experience other hormonal conditions, such as pregnancy and menstruation, may also have dry eye symptoms.
People with dry eye are often more likely to experience the side effects of eye medications, including artificial tears. For example, the preservatives in certain eye drops and artificial tear preparations can irritate the eye. These people may need special, preservative-free artificial tears.
Another cause for dry eye is exposure to a dry, windy climate, as well as smoke and air conditioning, which can speed tear evaporation. Avoiding these irritants can offer dry eye relief.
Symptoms
Dry eye symptoms may include redness, itchiness, grittiness, scratchiness, stinging, burning, dryness, excessive tearing and irritation, especially from smoke or wind, blurry vision, increased blinking, mucous discharge and general discomfort. The causes of these symptoms are even more variable and include older age, smoking, contact lens wear, environmental irritants (windy, dry air, smoke or air conditioning), rosacea, female gender, previous refractive surgery (LASIK, LASEK, or PRK where their corneas have reduced sensation due to incisions or tissue removal), a variety of medications (over-the-counter or prescription), certain autoimmune disorders (Sjögren’s syndrome, lupus, rheumatoid arthritis or some types of thyroid disease) and lacrimal gland trauma.
Dry-eye sufferers may find that they feel like they cannot keep their eyes open for very long. They may also find their eyes feel more uncomfortable after reading or watching television. In some cases, particularly among people who have extended gaze patterns, blinking does not occur frequently enough. People who work long hours at a computer are less likely to blink often, therefore are more susceptible to getting dry eye than people who don’t spend a lot of time in front of a computer monitor. As a result, the tears do not get spread across the eye properly and dry eye occurs. In all cases of dry eye, symptoms may develop or become exacerbated when the weather is windy, the air quality is poor or the humidity is low.
Treatment
Treatment of the underlying cause may control the progression of dry eye but sometimes, such an option is not available or the cause is unknown. By doing the following, symptoms may be managed:
- Artificial tears available over the counter can be used to lubricate the eyes and help maintain moisture. They come in different viscosity and content, so you may want to try several to find one that suits you best. Some lubricating drops are preservative-free more suitable for those who are sensitive to preservatives or those who use rewetting drops more frequently than six times a day. Because these are not medicated, you can use them as often or as rarely as you feel necessary.
- Lubricating gel or ointment may also be added to your routine, most commonly used at bedtime to prevent dryness and pain upon waking. (Dry eye due to vitamin A deficiency is more common in poorer countries, especially among children, but rare in the United States. Ointments containing vitamin A can help in conditions such as Stevens-Johnson syndrome or pemphigoid but not ordinary dry eye.)
- Lid hygiene routine consisting of hot compresses prior to face washing in the morning, evening, or both, and scrubbing the lids and lashes side to side using gentle cleansers like Cetaphil or Johnson & Johnson’s baby shampoo to clean out the crusted oils from the open pores and allow fresh oils and tears to be secreted for better lubrication.
- Punctal Plugs made of collagen or silicone may be applied by your eye doctor to help retain your tears in the eyes by blocking tears from draining through the small channels into the nose (nasolacrimal duct, also why your nose runs when you cry).
- In reducing evaporation of tears, a humidifier or pan of water on the radiator can add moisture to dry air, which is especially helpful in the winder when indoor heating is in use. Wraparound glasses may also reduce drying when outdoors or in windy situations (air conditioning or fan).
- Omega-3 fatty acids may provide relief by allowing the oil glands to produce better oils to achieve moisture retention and lubrication. These can be found in natural foods such as salmon, sardines, anchovies or flax seeds or by over-the-counter supplements.
- Prescription medication such as Restasis (cyclosporine) and steroid eyedrops may also be prescribed for dry eye management. Although some people respond very quickly and positively to Restasis, it may take four to six months before noticing any positive effects. As for steroid drops, it is not recommended for long-term use due to other severe side effects, such as glaucoma.
If you are suffering from dry eyes, please consult an eye doctor and start managing it today.