Dry Eye Disease

What Is Dry Eye Disease?

Dry eye disease (DED) is a common and often underdiagnosed condition that affects millions of people globally. It is characterized by insufficient tear production or poor tear quality, which can lead to discomfort, visual disturbances, and even damage to the ocular surface. The complexity of dry eye disease lies in the delicate balance required between the production and drainage of tears, as well as the quality of the tear film itself. Tears are more than just water; they consist of a complex mixture of water, lipids (oils), and mucins that work together to keep the surface of the eyes lubricated, nourished, and protected from infection. DED is a condition that, if left untreated, can cause ongoing irritation and discomfort, significantly impacting your quality of life.

Dry Eyes Affect Up to 50% of Adults

Dry eye disease is widespread. Research suggests that up to 50% of all adults experience dry eye symptoms at some point in their lives. It is especially common among people who spend lots of time in dry environments or in front of screens. It’s even more prevalent in people over the age of 50. Studies show that one in three older adults suffer from moderate to severe symptoms. This can lead to chronic irritation and a decrease in visual clarity, affecting day-to-day activities like reading or driving. Without proper treatment, dry eyes can also lead to inflammation and long-term damage to the cornea.

Evaporative Dry Eye

Evaporative dry eye is the most common subtype of dry eye disease, accounting for nearly 80% of all cases. This occurs when the oily layer of the tear film is compromised, leading to faster-than-normal evaporation of tears from the surface of the eye. The meibomian glands, which are located in the eyelids, produce the essential oils that prevent tears from evaporating too quickly. When these glands become blocked or inflamed, the tear film loses its stability, and the eyes can become dry and irritated. Blepharitis, a condition characterized by inflammation of the eyelids, is often linked to evaporative dry eye and can exacerbate symptoms if left untreated.

Aqueous Deficient Dry Eye

Aqueous deficient dry eye occurs when the lacrimal glands fail to produce enough watery tears to adequately hydrate the eye. This is more common in older adults, especially women, as hormonal changes can reduce tear production. Aqueous deficient dry eye can also be associated with systemic diseases like Sjögren’s syndrome, an autoimmune condition that affects moisture-producing glands throughout the body. Patients with this subtype of dry eye often experience significant discomfort and require targeted therapies to stimulate tear production and alleviate symptoms.

The Importance of Eye Exams to Test for Dry Eye

Proper diagnosis is vital for identifying the type and severity of dry eye disease, as treatment plans vary significantly depending on the underlying cause. Eye exams for dry eye disease often involve several diagnostic tests that assess tear production, quality, and the overall health of the ocular surface.

The Schirmer Test

The Schirmer test is one of the most commonly used diagnostic tools for dry eye disease. By placing a small strip of paper under the lower eyelid, the test measures how much moisture the eyes produce over a period of five minutes. If the eyes fail to produce enough tears, it indicates that the patient may have aqueous deficient dry eye. This simple test provides valuable insight into tear production and can help guide further treatment options.

Epithelial Staining

Epithelial staining is another test that can be used to diagnose dry eye disease. By placing a special dye like fluorescein or lissamine green in the eye, the healthcare provider can observe any damage to the surface of the eye. Areas of the cornea or conjunctiva that are not adequately lubricated will absorb the dye, revealing dry spots or areas of inflammation. This procedure is painless and helps to assess the extent of damage caused by dry eye disease. It’s also useful for tracking disease progression over time.

Meibomian Gland Evaluation

Evaluating the meibomian glands is a way to diagnose evaporative dry eye. During this exam, an eye care professional will examine the function and structure of the meibomian glands, either through manual expression of the glands or with advanced imaging techniques like meibography. If blockages or poor oil production in these glands are detected, treatments such as warm compresses or gland expression procedures may be required to restore the balance of the tear film.

Tear Break-Up Time (TBUT)

The Tear Break-Up Time (TBUT) test is used to measure how long it takes for the tear film to break up on the surface of the eye after a blink. A shorter TBUT indicates that the tear film is unstable and evaporating too quickly, a hallmark of evaporative dry eye. This test helps clinicians identify tear film instability and can be used to monitor treatment effectiveness over time.

Causes of Dry Eye Disease

Understanding the underlying causes of dry eye disease is essential for both treatment and prevention.

Common Factors That Cause Dry Eyes

Some of the most common factors that contribute to dry eye disease include:

• Age: Dry eyes are more common as we age because tear production tends to decrease over time.
• Biological sex: Women are more prone to dry eyes due to hormonal changes, especially during pregnancy, menopause, or while taking oral contraceptives.
• Environmental conditions: Wind, smoke, and dry air can cause tears to evaporate more quickly than normal.
• Inefficient tear production: This can occur due to the natural aging process or certain medical conditions.
• Decrease in tear quality: Poor-quality tears can evaporate too quickly, leading to dry eye symptoms.

Medications and Conditions That Can Cause Dry Eyes

Several medications and health conditions are known to cause or worsen dry eye disease, including:

• Autoimmune diseases: Conditions like Sjögren’s syndrome, lupus, and rheumatoid arthritis can impair tear production.
• Hormonal changes: Menopause and certain contraceptives can reduce tear production.
• Neurological conditions: Stroke, Bell’s palsy, and diabetes can affect the nerves responsible for tear production.
• Medications: Blood pressure medications, beta-blockers, antidepressants, antipsychotics, decongestants, and antihistamines are known to dry out the eyes.

Symptoms of Dry Eyes

Dry eye symptoms can range from mild discomfort to more severe issues that impact your quality of life. Common symptoms include:

• Dry, irritated, or red eyes: A constant feeling of irritation, redness, or dryness in the eyes.
• Itchiness: Persistent itching in the eyes that can be worsened by environmental conditions.
• Burning sensation: A stinging or burning feeling in the eyes, especially after prolonged screen time.
• Excessive tearing: Paradoxically, dry eyes can cause an overproduction of tears in response to the irritation.
• Foreign body sensation: Feeling like there is something stuck in the eye, even when there isn’t.
• Blurry vision: Dry eyes can lead to intermittent or continuous blurriness, especially when focusing on tasks like reading or working on a computer.

Dry Eye Treatment

Treating dry eye disease often involves a combination of lifestyle changes and medical interventions depending on the severity of the condition. Common treatments include:

• Eye drops: Artificial tears are often the first line of defense in treating dry eye disease. These eye drops are available over the counter and can help alleviate dryness and irritation by providing temporary moisture. However, they may not address the root cause of dry eye disease, particularly in more severe cases.
• Punctal plugs: For individuals with more persistent dry eye symptoms, punctal plugs may be recommended. These small devices are inserted into the tear ducts to block drainage, allowing the tears to remain on the surface of the eyes for longer. This helps keep the eyes more hydrated and can provide long-lasting relief for those with chronic dry eye disease.
• Dry eye spa treatments: Innovative treatments like dry eye spa therapy have gained popularity in recent years. These treatments involve a combination of heat therapy and massage to stimulate the meibomian glands and improve oil production in the tear film. Patients undergoing dry eye spa therapy often report significant improvement in symptoms after just a few sessions.
• Therapeutic contact lenses: For severe cases of dry eye disease, therapeutic contact lenses may be prescribed. These lenses, also known as scleral lenses, are designed to protect the cornea and trap moisture on the eye's surface, providing relief from chronic dryness. They are particularly effective for patients with severe evaporative dry eye or those who have not responded well to other treatments.

How to Prevent Dry Eyes?

As they say, an ounce of prevention is worth a pound of cure. There are several things you can do to reduce your risk of developing dry eye disease or worsening existing symptoms.

• Get regular eye exams: Regular eye exams can detect dry eye disease early, allowing for prompt treatment and management.
• Optimize your workspace: Adjust your computer screen to be at eye level and take frequent breaks to reduce eye strain.
• Use a humidifier: Adding moisture to the air can help prevent tears from evaporating too quickly, especially in dry or heated environments.
• Stay hydrated: Drinking plenty of water can improve overall hydration, including tear production.
• Wear sunglasses: Sunglasses protect your eyes from wind, dust, and UV rays, all of which can contribute to dry eye symptoms.
• Avoid cigarette smoke: Smoking or exposure to secondhand smoke can irritate the eyes and contribute to dry eye symptoms.

Dry eye disease is a widespread but manageable condition that can significantly affect your comfort and vision. With proper diagnosis and treatment, many of the symptoms can be alleviated, allowing you to enjoy daily activities without the ongoing irritation. If you are experiencing dry eye symptoms, it’s important to seek professional care to determine the treatment plan that’s best for you. Regular eye exams, lifestyle changes, and targeted treatments can help keep your eyes healthy and comfortable for years to come.