Dry eye syndrome is caused by a chronic lack of sufficient lubrication and moisture on the surface of the eye. Persistent dryness, scratchiness, red eyes, and a burning sensation are common symptoms of dry eyes, although excessive tearing may also be a symptom as a result of an overproduction of tears in a protective response to chronic dryness.
Tears consist of three essential components:
- The outer, oily lipid component, produced by the meibomian glands in the eyelids
- The middle, watery, lacrimal component, produced by the lacrimal glands above the outer corners of the eyes
- The innermost component, consisting of mucous or mucin, produced by goblet cells in the conjunctiva.
Each component of the tear film serves a critical purpose. Tear lipids prevent evaporation and increase lubrication, while mucins help anchor the tears to the ocular surface. A problem with any of those sources can result in tear instability and dry eyes
In dry eye syndrome, the lacrimal gland doesn't produce enough tears, or dysfunction of the meibomian glands reduces oil output, leading to excessive evaporation of the tears. This is called evaporative dry eye and is now considered to be the primary cause or a contributing factor of most cases of dry eye.
Dry eye syndrome has many causes. It occurs as a part of the natural aging process (especially during menopause in women); as a side effect of many medications, such as antihistamines, antidepressants, certain blood pressure medicines, Parkinson's medications and birth control pills; or because you live in a dry, dusty or windy climate.
Air conditioning or heating can dry out your eyes as well. Another cause is insufficient blinking, such as when you're staring at a computer screen all day.
Dry eye syndrome is more common among women, possibly due to hormonal fluctuations. A recent study also indicates that the risk of dry eyes among men increases with age.
Recent research suggests that smoking, too, can increase your risk of dry eyes.
With increased popularity of cosmetic eyelid surgery (blepharoplasty) for improved appearance, dry eye complaints now occasionally are associated with incomplete closure of eyelids following such a procedure.
Dry eyes also are a symptom of systemic diseases such as lupus, rheumatoid arthritis, ocular rosacea or Sjogren's syndrome (a triad of dry eyes, dry mouth and rheumatoid arthritis or lupus).
Long-term contact lens wear is another cause; in fact, dry eyes are the most common complaint among contact lens wearers.
Recent research indicates that contact lens wear and dry eyes can be a vicious cycle. Dry eye syndrome makes contact lenses feel uncomfortable, and evaporation of moisture from contact lenses worsens dry eye symptoms. Newer contact lens materials and lens care products can help reduce contact lens dryness.
Treatments for Dry Eyes
- Artificial tear drops and gels are lubricants that may provide relief. Some artificial tears are formulated to address specific tear deficiencies, such as insufficient lipids.
- Nutritional supplements containing omega-3 fatty acids and flax seed oil can decrease dry eye symptoms. Good natural sources of omega-3s include cold-water fish, such as sardines, cod, herring and salmon. Drinking more water can help, too. Mild dehydration often makes dry eye problems worse. This is especially true during hot, dry and windy weather. Simply drinking more water sometimes reduces the symptoms of dry eye syndrome.
- LipiFlow treatment (TearScience) is an in-office procedure that clears blocked meibomian glands and restores normal function. Meibomian gland dysfunction (MGD) is now recognized as a primary cause of or contributor to most cases of dry eye.
- Warm compresses applied to the eyes, followed by manual expression of the meibomian glands helps in treating MGD and evaporative dry eye.
- Combination antibiotic/ steroid anti-inflammatory drops may relieve underlying low-grade eyelid infections and provide relief.
- Restasis (cyclosporine) is a prescription eye drop that helps to produce more tears by reducing inflammation.
- Lacrisert, a tiny rod filled with a lubricating ingredient (hydroxypropyl cellulose) is placed just inside the lower eyelid, where it continuously releases lubrication for the eye.
- Punctal occlusion. We can insert small plastic plugs into the tear drainage canals to block the tears from flowing out of the eye, allowing your own tears to lubricate the eyes longer. This is a painless, quick procedure done at the doctor's office. Dr. Jeruss uses a new type of punctal plug that changes shape from the warmth of your eye to conform to the size of your tear drainage canal. Advantages of this type of plug are that one size fits all, so measurement is unnecessary, and nothing protrudes from the tear duct that could potentially cause irritation. With some people, however, punctal plugs aren't effective enough, so their tear ducts need to be closed surgically (punctal cautery).
- Sometimes people use eye drops that are advertised to "get the red out" to treat their dry eyes. While these drops can reduce or eliminate eye redness temporarily, they may or may not be effective at lubricating your eyes, depending on the formulation. Also, your eyes can develop a tolerance or "rebound effect" to the eye-whitening agents (vasoconstrictors) in these drops, which can cause even more redness over time. Redness-relieving eye drops can cause other adverse effects as well, especially if you use them too often.
- For contact lens wearers, you will likely benefit from switching to a better soft lens that resists drying out or switching to a rigid gas permeable lens.