Dry eyes may be the consequence of decreased tear formation, the result of a slow blink rate, or both. Blinking, which is so automatic a function that few of us are aware of it, spreads a thin film of tears over the eye. A slow blink rate may allow this film of tears to dry. Eye dryness results in a small but real change in visual acuity. Television may be a little less clear and crisp, and glare may be worse at night.
Elderly patients are more susceptible to dry eyes for several reasons. Changes that occur in the eye with aging may result in a decrease in the total output of tears. Many drugs, such as those used in the treatment of Parkinson’s disease, glaucoma, depression, and gastrointestinal problems, can decrease the total volume of tears as a side effect. Problems that cause muscle weakness can lower the blink rate.
A number of diseases are associated with dry eyes. Chronic infections of the eye or the lids may be a cause. Neurologic changes following some strokes may lead to dry eye. Lack of vitamin A may cause this as well.
The environment also may contribute to the problem of dry eyes. Air conditioning lowers humidity. Prolonged residence in a dry, air-conditioned atmosphere can speed the drying rate and add to the problem of dry eyes. This may also occur during airplane travel. High-flying, pressurized, air-conditioned planes are notoriously low in humidity. The widespread use of dry forced-air heating in winter also leads to prolonged periods of low humidity and can make the problem of dry eyes worse. Elderly patients are particularly susceptible to these environmental conditions.
Most people are familiar with the gritty, irritating feeling of dry eyes. Often there is an associated infection, with the eyeball appearing red and with injected blood vessels. In cases in which the cause of dry eyes is not readily apparent, it is possible for the ophthalmologist to conduct a test to evaluate tear production.
Important Points in Treatment
Your doctor will examine you to discover if any of the conditions associated with dry eye are a cause of the problem. Treatment of the underlying condition, if possible, is important to the management of dry eyes. The dry eye itself is most easily managed with the use of artificial tears. These are drops that may be put in the eye as needed to renew the tear film. You must be careful to keep the dropper tip clean. Eye drops come in small bottles intentionally to ensure that patients change to new, clean droppers regularly. Dirty droppers can lead to eye infections. Your ophthalmologist can advise you about the suitability of other slow-release preparations of artificial tears.
Notify Our Office If ...
- You have a persistent problem with glare that interferes with vision. Dry eyes lead to a small but real change in visual acuity. Television may be a little less clear and crisp, and glare may be worse at night.
- You experience red eyes or burning following the start of a new medication. Several drugs produce dry eyes as a side effect. These include some but not all of the drugs used for the treatment of Parkinson’s disease, anxiety, depression, diarrhea, irritable bowel syndrome, and heart arrhythmias.
- You have sudden onset of redness and burning in your eye. These symptoms can suggest eye infection. Dry eyes are most easily managed with the use of artificial tears, but you must be careful to keep the dropper tip clean. Dirty droppers lead to eye infections.