What is Dry Eye Syndrome?

Dry Eye Syndrome is a growing epidemic that has eye care professionals around the world concerned. Both optometrists and ophthalmologists are working together to evaluate and treat patients that suffer from this very distracting eye problem. Dry eye syndrome is similar to what it sounds like but constitutes a lack of lubrication or moisture in the eyes related to the tear film and production of natural tears. This syndrome can be caused by a wide variety of factors including the natural aging process, over the counter cold medicines, contact lens wear and environmental factors.

If you suffer from a scratchy, dry or a burning sensation you may be experiencing dry eye. In order to properly diagnose this problem you should come into our office for a visit with one of our dry eye specialists. At your visit we will conduct an examination and testing to dermine the severity of the dryness.

Understanding The Tear Film

It is important to understand the importance of the tear film and how this relates to the dry eye disorder. The tear film is made up of three unique layers: an oily layer, a watery layer, and a mucin layer. Small glands at the perimeter of the eyelid, called meibomian glands, produce the outer, oily layer of the tear film. The main purpose of this oily layer is to smooth the tear surface and decrease evaporation of tears. The middle, watery layer is the largest of the three layers, and it makes up most of what we ordinarily think of as tears. This watery layer is produced by small glands scattered through the conjunctiva, the delicate membrane lining the inside of eyelid and covering the eyeball, and by the major tear gland, the large lacrimal gland. The innermost layer consists of mucus produced by goblet cells in the conjunctiva. This layer allows the watery layer to spread evenly over the surface of the eye and helps the eye to remain quite moist. Without mucus, tears would not stick to the eye.

There are two main forms of the disease: evaporative and aqueous deficient.

Evaporative Dry Eye, which account for 86%¹ of all dry eye cases is caused by blockages in the Meibomian glands located in your eyelids.

This condition of the obstructed glands is known as Meibomian Gland Dysfunction. These glands are responsible for creating the lipid (oil) layer of the tears. When the glands are not working as they should, you don't have enough tear film oil. And your tears – which lubricate your eyes and keep them comfortable - evaporate too quickly. An insufficient oil layer can cause your tears to evaporate 4x-16x faster.

Aqueous Deficient Dry Eye occurs when the lacrimal glands do not create a sufficient amount of aqueous (water) to keep the eyes moist.

1-Limp MA, et al. Distribution of aqueous deficient and Evaporative Dry Eye in a clinical-based patient population. Cornea. In press.

Dry Eye Symptoms from Lipiflow on Vimeo.

What are some of the risk factors for Evaporative Dry Eye?

• Hormonal changes in women during menopause – particularly decreasing levels of estrogen – can cause thickening of the oils secreted by the Meibomian glands, which results in blockages.
• Decreased estrogen levels may enhance conditions under which staphylococcal bacteria can proliferate in the Meibomian glands. The result is a decreased oil secretion rate.
• Additional factors that may cause or exacerbate Meibomian Gland Dysfunction include age, contact lens use and hygiene, cosmetic use, and illnesses, particularly diabetes.