DRY EYES
The tears of the eye are composed of more than just water. Actually, there are three fluid components making up tears in human beings: water, mucous and oil, along with various organic molecules. Most people have sufficient tears to maintain proper eye moisture and lubrication. Any one of the tear fluids may be deficient and cause the sensation of dry eyes. Dry eye syndrome (DES) is more frequent in women than in men, and more prevalent in an older population of patients.
Causes of Dry Eye Syndrome
There are numerous microscopic tear glands on the surface of each eye. With age, some of these glands seem to function less well than they did when the patient was younger. Some patients do not fully close their eyes when they blink or during sleep, leading to excessive tear film evaporation and dryness of the eyes. Patient's with some forms of arthritis may suffer from Sjogren's Syndrome, an autoimmune condition involving arthritis, dry eyes and dryness of the salivary glands in the mouth. Rarely, more severe inflammatory diseases like mucous pemphigoid can also have dry eyes as part of the symptoms constellation.
Diagnosis of Dry Eyes
Most patients with dry eye syndrome report a sensation of burning or stinging of their eyes during all waking periods. The eyes may be especially sensitive to light or windy conditions too. Low ambient humidity, such as may be found in an air conditioned home or airplane cabin, may also exacerbate symptoms. Patient's with Sjogren's Syndrome may complain of dryness of their mouth and/or nasal passages too.
Paradoxically, lots of patients complain of excessive tearing of their eyes, even though the underlying pathology is decreased baseline tear production. Because of the decreased moisture, the eyes become irritated and uncomfortable. Reflex tear secretion occurs (like when you peel and onion and its fumes irritate your eyes) producing enough extra moisture that the tears may overflow your lids.
There are a number of sophisticated laboratory tests to determine exactly what components of the tears are decreased in a dry eye patient. But the simplest test involves only a small strip of paper and some topical eyedrop anesthesia. With this Schirmer Test, a small strip of absorbent paper is placed in the corner of each eye for a few minutes. Then the quantity of absorbed moisture is determined and compared to an average value.
Treatment Options for Dry Eye Patients
Because we have no way of restoring or increasing tear production, our therapeutic goals are to make sure the eyes are moist enough to reduce irritation and to prevent infection to any exposed surfaces of the eye. Although inconvenient, many patients receive adequate relief by using artificial tear eyedrops several times a day, or even more frequently if necessary. Additionally an ophthalmic ointment may provide sufficient lubrication overnight if applied at bedtime.
If the patient's condition is severe, artificial tears alone may not be adequate for relief. Your optometrist may recommend closing the tear puncta (tear drainage openings) that are located in each of the four eyelids. The procedure is done using plastic punctal plugs. By closing the drain openings, more of the natural tears will stay on the eye surface for a longer time, rather than be drained from the eye in the normal fashion. After "punctal occlusion" you may still need artificial tears, but perhaps less frequently than before plug placement.