The glandular secretion is controlled by nerve impulses and emotions. With a malfunction of this sensitive system of tear production and distribution, alleged "dry eyes" originate. Here, either the total volume of the tears is reduced or the share of single components is reduced compared to the other components.
Ophthalmology knows different terms for this disease:
- dry eyes sicca syndrome (sicca = dry)
- keratoconjunctivitis sicca, KCS (=dry inflammation of the cornea and conjunctiva)
- Morbus Sjörgen (Sjörgen´s disease,named after the man who first described the disease, however, several other physical complaints are also found here,such as dry mouth and/or rheumatism).
The most appropriate term is "wetting impairment", since this term describes the functional disorder most clearly. Dry eyes very often are a chronic disease which requires constant treatment.
How do you know that you have this disease?
A variety of symptoms may indicate dry eyes.
The most frequent complaints of patients with dry eyes are:
- dryness sensation
- sand grain sensation
- pressure sensation of the eyes
- smarting adherence of the lid to the eyeball when the lids are closed
- light sensitivity
A part of the patients also suffer from increased watering of the eyes, especially outdoors, in windy weather and also in closed rooms. In addition to the tear flow impairment, also a change in the tear film components may exist here, mostly a decrease in the fatty components, so that the aqueous component relatively predominates and, as already explained above, cannot be kept back any longer by the fatty layer and is dripping down over the lid margin.
Also in this case, the result is that a sufficient volume of liquid is no longer available for the cornea and the conjunctiva, thus leading to dry eyes.
Different from wetting impairments are allergies, where, however, the major complaints are swelling and itching of the conjunctiva. Also here, frequently a course of the complaints depending on the time of the year is typical (hay fever).
Causes of dry eyes
Dry eyes may originate due to different factors. The most common causes are:
- decreasing tear production
- in old age rheumatic or internal diseases,
such as polyarthritis, diabetes, thyroid diseases Ediseases where antibodies against kendogenic substances are formed (Sjörgen´s disease, lupus erythematodes, sclerodermia)
- skin diseases hormonic changes (menopause) neuroparalysis, e.g. after a stroke
- consumption of certain drugs,
such as ß-blockers, contraceptive pill,
narcotics and tranquilizer malnutrition climatic influences (hot and dry environmental air, time of the year, air-conditioning)
- environmental strain (ozone, dust, solvent fumes etc.)
- monitor work
- chronic use of vasoconstricting eye drops (alleged whiteners)
Frequently, there are several causes for dry eyes, which cannot always be determined. Therefore it is important that you inform your ophthalmologist if you are taking drugs and if so which ones, which diseases and which complaints you have in addition to dry eyes.
Consequences of the disease
First, the increase in complaints is most obvious. The foreign body sensation can increase to smarting and pain. The eyes are almost permanently red. After sleep, it is hard to open the lids. Chronic blepharitis can turn the pathological picture more severe. In addition to these subjectively disturbing complaints, the sensitive tissue layers of the ocular surface can also be damaged objectively. This is due to the fact that the hydrochloride content of the tears, which is assumed to be responsible for corneal damage, is increased in dry eyes. The consequence of an impairment of the tear film is the insufficient moisturing and drying out of the cornea and of the conjunctiva. As a result, first fine defects in the superficial corneal and conjunctival layer occur. The eye turns increasingly red, a chronic corneal and conjunctival inflammation originates.