The Leading Causes of Dry Eye Disease

The Underlying Cause of Dry Eye Symptoms

Long term effective treatment for Dry Eye symptoms has eluded many who have come to rely on short term relief from drops, various at-home symptom relief remedies or other prescribed medications. For many, managing symptoms is a frustrating process. The key to effective Dry Eye treatment is to understand the underlying cause of the symptoms.

Dry Eye is generally caused by an imbalance in the tear film that acts as a shield on the surface of our eyes. There are two primary contributors to tear film imbalance. The first is decreased tear production. In recent years, we have learned that true reduced tear production is rare. What we know now is that the problem almost always originates with blockage of the tiny Meibomian Glands in our eyelids. These glands produce essential oils that form the top layer of the tear film and are the core protective element that is essential to long-term visual comfort.

When the Meibomian glands are blocked or the glands have been compromised, the eye becomes exposed. This leads to dry eye signs and symptoms. This is known as MGD or Meibomian Gland Dysfunction. MGD is easy to diagnose and manage. The treatment of MGD is essential for the long term management of dry eye.

The Leading Cause of Dry Eye Symptoms: Blocked Glands in The Eye Lids

Fortunately, most Dry Eye patients boast healthy tear production as proven by a common symptom of Dry Eye, excessive tearing. As tear production is generally not the root cause of Dry Eye, your eye care professional should check for gland blockages and the structure of your Meibomian Glands in your eyelids.

Gland blockages can occur over time from debris that is caught in the eyelids, digital device and computer usage and, for women, just putting on make-up over the course of many years. While Miebomian Gland Dysfunction, or MGD, is most often detected in adults over 40, the condition does not discriminate based on age and is often seen in kids and young adults as well. That is why checking for MGD should be a part of your regular eye exam. MGD, if caught early, is the best way to avoid chronic dry eye symptoms. More importantly, you can prevent the potential for substantial permanent gland loss.

Normal Gland Structure

Normal Gland Structure

Gland Shortening And Los

Gland Shortening and Loss

Significant Gland Loss

Significant Gland Loss

Severe Gland Loss

Severe Gland Loss

External Dry Eye Causes

Dry Eye Syndrome and chronic Dry Eye symptoms can have significant impact on daily lifestyles and can impede on simple activities such as reading, working on a computer, enjoying the outdoors or watching a TV. Those same daily activities that are impeded by Dry Eye symptoms are also the same activities that can be contributing causes to Dry Eye.

For example, looking at computers or digital devices for long periods of time can contribute to decreased blink rates. Blinking is essential to activating the oil-producing Meibomian Glands and spreading those oils across the surface of the eye. When blink rates decrease, it impacts long term functionality of the glands and can lead to MGD or even irreversible damage if MGD is not detected and treated early. Other contributing factors that cause Dry Eye symptoms to flare up are dry climates, smoke, indoor air circulation, and wind. Some of us are just lucky with Dry Eye being a product of the aging process.

Medical Related Dry Eye Causes

In addition to environmental factors that contribute to Chronic Dry Eye symptoms, there are various diseases, medications or medical procedures that can cause Dry Eye symptoms. If you are experiencing any of the below medical conditions or receiving any of these treatments, you should discuss with your eye doctor to get to the root cause of your Dry Eye symptoms. The following are common conditions or treatments that can lead to chronic Dry Eye Symptoms:

  • Rheumatoid Arthritis, Sjogren’s syndrome, thyroid disease and lupus
  • Medicines such as beta-blockers, antihistamines, diuretics and anxiety medications
  • Refractive surgery such as LASIK surgery
  • Various prescription and non-prescription medications
  • Swollen, red irritated eye lids, commonly referred to as Blepharitis
  • Out-turning of the eye lids (ectropion) and in-turning of the eye lids (entropion)
  • Contact lens use for long periods of time

Understanding the Tear Film

The tear film is a complex structure of mucin, tears and oil that protects the surface of the eyes. When the tear film is compromised, it results in a variety of symptoms, most of which have been associated with Dry Eye and MGD (Meibomian Gland Dysfunction). Understanding the tear film is key to seeing the clear differences between tear deficiency issues and MGD, especially since MGD is more common and has greater long term impact on Dry Eye symptoms.

Mucin Layer

The Sticky Foundation

The mucin (mucous) layer at the bottom of the tear film provides a “sticky” foundation and acts as a barrier to the eye surface.

Aqueous Layer

The Watery Center

The aqueous layer is the “juicy” center that is comprised of tears produced by the lacrimal glands.

Lipid Layer

The Oily Top

Finally, the top “oily” lipid layer of the tear film is made up of lipids or oils produced from the meibomian glands. When MGD is present, our glands do not consistently produce the oil necessary for a stable tear film and the aqueous layer will evaporate.

Eye Diagram