March is national Save Your Vision Month. Dry Eye Disease is often thought to be just an annoyance. Dr. Wayne Whitmore discusses how the chronic loss of healthy tear fluid can cause permanent visual change. This is our final post for Save Your Vision month. We hope that the information provided by members of our medical advisory board about eye care and eye disorders has been helpful. Vision and health are more intertwined than most people may realize.
Dry Eye Disease (DED) has become an increasingly recognized problem by eye care professionals. It can cause annoying signs and symptoms which include: a scratchy feeling as if something is in your eye, a burning sensation, intermittently blurry vision and difficulty reading, red eyes, and paradoxically, excessive tearing. DED affects women more than men and is more common with increasing age.
The tear fluid that coats the ocular surface of the eye is a complex mixture of three components, which can be roughly described (starting from the outside surface) as a lipid layer, a watery (or aqueous) layer, and a mucous layer. All layers are essential to produce a healthy and stable tear film and to prevent dry eye symptoms. A deficiency of any one of these components can lead to DED. Each of these components is produced by separate glands on the eyelid margin (meibomian glands – lipid layer), in the conjunctiva (goblet cells – mucous layer), beneath the conjunctiva (glands of Wolfring and Krause – basal aqueous layer), and by the lacrimal gland (reflex aqueous tear layer). The lacrimal gland is responsible for the reflex tearing that happens when something gets in the eye or scratches the cornea, and when we cry. Dryness can sometimes be so bad that it can cause reflex tearing when it is very cold or windy outside. Unfortunately, these reflex aqueous tears do not contribute to a balanced tear film to help DED.
DED is multifactorial and can be caused by environmental factors (dry air/low humidity or windy settings); medications (both topical and systemic which suppress secretions); other types of eye disease (such as conjunctivitis or “pink eye”); after eye surgery (cataract extraction, etc.); diseases of the eyelids (such as blepharitis); eyelid trauma (causing scarring, which creates a mechanical malfunction of the eyelids); and neurologic conditions (such as Bell’s palsy, which prevents proper closure of the eyelids.) Various systemic disease processes can affect the production of a normal tear film, including autoimmune diseases such as rheumatoid arthritis, systemic lupus erythematosus, and nonspecific connective tissue disease.
Treatment can involve modification of one’s living environment, changing or stopping certain medications, or regularly using lubricating eye drops (“lipid”, “aqueous”, and/or “mucous” types) in the daytime and lubricating ointments at bedtime. Other treatments for DED include medications (Restasis, Xiidra, and topical steroids), punctal plugs (which are inserted into the tear drainage system to help retain one’s own tears), conjunctival inserts (Lacrisert, which slowly releases tear fluid throughout the day), and special glasses made with moisture chambers. Topical androgens via skin patches were recently shown to be successful in treating DED.
More severe cases of DED can cause scarring which can result in loss of vision with greatly increased risk for infection and corneal ulceration which can result in loss of the eye. These cases require more aggressive treatment, which can include different types of surgery on the eyelids (including conjunctival grafting and surgery to narrow the eyelid opening – tarsorrhaphy).
Determining the cause and severity of the DED is particularly important for treatment and is a reason for getting a thorough eye examination by an ophthalmologist (an “eye MD”). If your eyes are chronically irritated or red, or if you have any difficulty seeing, you should get a complete eye examination to get the correct diagnosis and the proper treatment.
