Dry Eye Disease (DED) is one of the most common disorders we see and manage in our practice. It has a variety of causes and can range from minor symptoms to severe discomfort. The incidence is higher in women but can affect men as well and tends to worsen as we age.
To understand DED, one needs to first know the basic anatomy of the healthy tear layer that covers our cornea. It consists of an inner mucous layer (from the goblet cells on the eye surface), a middle water / aqueous layer (from the lacrimal gland under the eyebrow bone) and an outer oil / lipid layer produced from the meibomian glands located at the eye lid margin near the lash line. Any one (or all) of these layers can be diminished and cause DED symptoms.
Dry Eye Symptoms
- Stinging or burning eyes
- Stringy mucus in or around the eyes
- Excessive eye irritation from smoke or wind
- Excess tearing
- Discomfort when wearing contact lenses
- Fluctuating vision
Why would DED cause ‘excess tearing’? One of the most common questions we get. It’s because the body is better at making water from the lacrimal gland then it does in making mucous or oil. So, if any of these layers is diminished, the body tries to ramp up water (tears) from the lacrimal gland to make up for it. But water is not a good lubricant alone and only leads to excess tearing. It can be a sign that the other layers are reduced.
What causes DED?
Often, it is multifactorial but here are some common associations:
- Certain medical conditions, including diabetes, rheumatoid arthritis, lupus, scleroderma, Sjogren’s syndrome, thyroid disorders and vitamin A deficiency.
- Certain medications, including antihistamines, decongestants, hormone replacement therapy, antidepressants, and drugs for high blood pressure, acne, and birth control.
- LASIK / PRK, though symptoms of dry eyes related to this procedure are usually temporary.
- Tear gland damage from inflammation or radiation.
Increased Tear Evaporation
Sometimes, dry eyes can be caused by environmental factors that increase the rate tears evaporate. Wind, smoke, or dry air can cause rapid tear evaporation. Concentrating on something for a long period of time, such as working on a computer or driving, may cause you to blink less often than normal. If you are not able to replace lost tears quickly enough, this may also cause your eyes to become dry.
Meibomian Gland Dysfunction (MGD) is a common association with DED as it disrupts the production of a healthy oil layer of the tear film. This outer oil layer is what stabilizes the tear film and keeps the other layers from evaporating away. As a machine needs oil to reduce friction, so does the eye. Moving eyes and blinking can cause friction and DED symptoms. So, a healthy oil layer is vital. Rosacea is a skin disorder that can also be associated with MGD. The problem with MGD is that, instead of the glands producing a normal oil similar in consistency to olive oil, the glands get plugged with thickened secretions. When we target treatment to clear these blocked glands, it looks like toothpaste coming out. Blocked glands can also lead to styes. How do we keep these glands from getting plugged? In addition to eyelid cleansing and occasional warm compresses, its also helpful to take a good Omega-3 supplement which promotes thinner secretions from these glands. Although there are many brands sold, they can be quite variable in how they are absorbed and what actually gets to the eye. One brand that has been proven in many dry eye studies to benefit patients with DED is PRN Omega 3 Dry Eye Supplement and it helps that it is made in the USA.
Artificial tears can certainly help, especially in milder forms of DED. Lubricating eye gels and ointments can help the dry cornea recover during the night when tear production naturally reduces anyway. Humidifiers, especially in the bedroom, are helpful during cold and dryer months. Omega 3 supplements are always recommended and good for general health. Warm compresses and good lid hygiene is beneficial to help keep the eyelid glands functioning. This can be done with a simple washcloth under warm water with a small amount of baby shampoo. With the eyelids closed, gentle cleansing is done followed by rinsing with warm water. Doing this at least every other day can be very effective. Targeted iLux™ treatment of the meibomian glands performed in the office helps to clear blocked glands so they can produce a healthier oil layer. Other treatments may include punctal occlusion, where a tiny plug is inserted in the drainage opening of the eyelid where tears exit the eye, as well as prescription eye drops, and even using one’s own blood serum specially made to use as eyedrops.
If you are experiencing persistent dry eye symptoms, schedule an appointment with your eye doctor. They will be able to help you identify the cause and create a treatment plan that will help your eyes stay healthy and more comfortable.