Our eyes constantly produce a lubrication called tears. Tears are not only important in lubricating (like oil) the eyes to allow for smooth blinking, but also, help remove foreign debris from the eye and provide important nutriments to the eye. The tears are made up of two major components: a watery component called aqueous and sandwiched between two lubricating layers (mucin and lipid layers).
The lubricating component of the tears reduces surface tension, which eliminates beading of the tears, and causes the tears to spread on the corneas (A drop of water on glass beads, spreading of the water results in dry spots, lubrication eliminates this problem). Normally tears are reflexively produced to maintain moisture of the eyes. Currently, the blink reflex to spread the tears is mediated by subliminal pain induced by dryness via the corneal nerves to the brain. The message is to produce tears. If corneal sensation is altered by lack of oxygen reducing the ability of the nerves to respond; LASIK surgery cutting the corneal nerves; contact lenses, wind or other irritants normal tearing is decreased.
If there are not enough tears a message is sent to the brain – produce more tears. Unfortunately, these tears are very watery, instead of lubricating the eye they dry the eye. The process is similar to spending too much time swimming in the ocean, the skin becomes dry. “Watery tears”, like water on your skin causes dryness. This results a new message to produce more tears. Once again, more tears are produced which dries the eyes further. This is why tearing (wet eyes) are usually the result of dry eyes.
Lastly, current research suggests that dry eye may also be caused by auto-immunological disease. The eye produces inflammatory mediators (cytokines etc.) which cause an inflammatory reaction and decrease in lubrication. New medication such as Restasis may stop the auto-immune inappropriate inflammatory reaction. The result is repair of the lacrimal gland and the resumption of normal tearing.
Is There Anything That Makes Dry Eyes Worse?
As we grow older we produce fewer lubricates (mucin and lipid layers of tears)
Certain diseases like arthritis cause drying of mucous membranes, e.g., mouth and eyes
Menopause and during pregnancy result in drying of the eyes
Medications such as anti-histamines, anti-depressants, sleeping bills, alcohol, diuretics or beta-blockers decrease
Contact lenses increase the evaporation of tears
Dry, windy conditions, winter (decreased humidity), pollution decrease tear production
Dry Eye problems are common complaints amongst New Yorkers. They result in symptoms of dryness, irritation, sandy or gritty feeling, foreign body sensation, tearing, and/or itching. The symptoms increase during the winter since our apartments and homes are very dry with humidity levels less than 30%. In addition, patients are trying to wear contact lenses or staring at computer screens with a decreased blink rate.
What Can We Do About Dry Eyes?
Well if you have blepharitis or meimbomitis then we must eliminate this obstacle. Put a humidifier in your apartment and/or by your desk at work. Keep it on. Otherwise, we need to supplement your tears with artificial tears. Some brands are better than others. Patients who need to be maintained on long term use should use non-preserved artificial tears other wise less expensive artificial tears may be used. My favorite brands in order are:
BION tears or Tears Naturale
Genteal Gel (at night or for severe dry eyes during the day)
These drops can be used every once in while in mild cases, more frequently (four times a day in chronic cases) or one drop every hour in severe cases. If you have real dry eye and the eyes improve with the drops do not stop just because you feel better. If you have a real dry eye try Genteal Gel, it stings on insertion and will blur your vision for a minute or two, but lubricates for a longer time. Lacrilube is also useful just before going to sleep. Some patients do not close their eyes when they sleep. If your eyes don’t close completely during sleep, try to tape one eye shut at night. Alternate the taping sequence. In extreme cases tape both eyes.
I Hear that the FDA Just Approved a New Drop?
Restasis (cyclosporine by Alcon) is approved for the long term improvement in dry eye management. This drop actually increases the quality and quantity of the tears lubricating your eye. It is used twice a day and takes approximately three months before initial results are seen and six months before significant results are seen. The drop is associated with stinging upon use. Make an appointment and see if you are a candidate.
What About My Diet?
Most Americans are starved of Omega-3 fatty acids which are essential for tear production. Omega-3 fatty acids are found in salmon, walnuts, mackerel, sardines and herring. On the other hand we eat too much Omega-6 fatty acids which are found in milk, butter, ice cream, cow meat, fried foods, cookies, cakes, and pizza. The bad Omega a-6 fatty acids create inflammation throughout the body including blepharitis and meibomitis of the eye.
Thus, we need more of the good guy Omega-3 fatty acids. Flaxseed oil contains an abundant of oVita a-3 fatty acids. Apparently flaxseed oil works best with fish oil. Lastly, vitamin E may have a positive effect in the production of tears. If you want a pill which contains all of these ingredients TheraTears Nutrient has it all. The dosage is either 4 pills in the morning or throughout the day.
What If the Drops Don’t Provide Enough Lubrication?
The tears are made and drained. The tears are drained by the lacrimal duct into your nose and then into your throat. That is why you can taste your eye drops. To preserve your tears a small little plug can be placed in your drain (the tear duct), like putting the plug into the sink. This keeps most of your tears from draining out. The procedure is simple, painless and performed right in the office. Lastly, if these methods do not work swim goggles can be worn with a few drop of fluid placed inside to increase the humidity.