Dry Eye Disease
Dry Eye Disease if a group of diseases which results in dryness of the conjunctiva and/or cornea, resulting in symptoms of burning, foreign body sensation, excess tearing and redness. While most dry eye patients will have the same symptoms it is very important for the eye doctor to understand the underlying cause of the dryness:
Evaporative dry eye: usually due to blepharitis, specifically to meibomian glands dysfunction, the eye no longer produces quality tears. Because of the poor quality of the tears, they tend to evaporate leaving the eye exposed to the environment and triggering signs and symptoms of dry eye. At first patients may not have any symptoms. Then our patients will usually complain of a burning sensation after hours on a computer, some redness and often excess tears running off. This can seem counter intuitive. How can someone have epiphora (excess tearing), while having dry eyes? The normal tears are comprised of three layers: lipid, aqueous and mucous layers. When all those layers are present, tears are stable and maintain the eye moist. In evaporative dry eye, the lipid layer is of poor quality/quantity so tears can evaporate. As a reflex, the lacrimal glands will respond by producing reflex tearing, which is only aqueous or water. Those tears cannot stay on the eye because they are unstable. One mistake most patient make at first it to use OTC drops "for red eyes". Those drops solve nothing and can actually make the problem worse: they contain chemicals that result in vasoconstriction, making the eye seemingly look whiter; but they don't solve the root of the problem, can be toxic for the eye, resulting in more tissue damage. Lastly, there is a strong rebound effect: the more you use the drop, the least effective it becomes, and the more you need to use it. This is known as tachyphylaxis. Evaporative dry eye is treated by targeting the root of the problem: lid hygiene, warm compresses or medicines are used to help with the blepharitis component so your eyes can once again produce quality tears. In recent years, studies have shown that low dose doxycycline for several months had a positive effect on the inflammation of those sebaceous glands.
Pharmacological or iatrogenic dry eye: many if not most drugs we use can increase dryness. This is well known for allergy medicines, sleeping pills, anti depressants and so many others. If you must use those medicines, it is recommended you use artificial tears to prevent your eyes from becoming too dry.
Inflammatory dry eye: In recent years, eye doctors came to the understanding that in most dry eyes, there is an inflammatory component. With a lot of similarities to auto-immune diseases, the lacrimal gland of the eye stops functioning properly because it is inflamed. Those inflammatory mediators are also released in the tear film making the signs and symptoms of dry eye worse. Your optometrist or ophthalmologist can judiciously use anti-inflammatory agents in the form of eye drops to limit the inflammation and make your eyes produce more tears. There are currently two drugs on the market which are FDA approved to treat dry eye. They have a very safe profile, very little side effects. They can be used by your eye doctor if artificial tears alone do not help with your dry eye syndrome.
If you suffer from dry eyes, come see your eye doctor in North Miami for an eye exam and a treatment plan. Ready to say good bye to those red, irritated eyes?