Studies
The treatment of dry eyes starts with an examination by an ophthalmologist. There are various examination methods that are suitable for making a diagnosis: The ophthalmologist can easily detect clouding of the cornea and redness of the conjunctiva. In order to also detect minor corneal damage, the doctor applies eye drops containing dye to the eyes and then examines them under bluish light.
Small corneal defects and dead cells then become fluorescently noticeable.
- Examination with the slit lamp
The dye also helps to assess the stability of the tear film on the ocular surface. For this purpose, the so-called “Break Up Time (BUT)” is determined, also called “tear film break up time”.
The longer this tear film break-up time, the more stable the tear film is. This is evaluated with the eye open and stands for the time that elapses from the last blink of the eye until the tearing of the tear film colored by the dye. In a healthy eye it is about 20 seconds.
Another possibility for the assessment of a possible dry eye is the so-called Schirmer test. For this test, small filter paper strips are hung in the lower eyelids of both eyes. These strips are left in the eyes for 5 minutes, during which time they soak up tear fluid. In a healthy eye, the length of the moistened stretch is at least 10mm, while values below this are indicative of a dry eye.
- Break Up Time
- Schirmer Test
Treatment of symptoms
The complaints of dry eyes are treated superficially with artificial tears in the form of eye drops. These replace the too sparse natural tear film to the extent that the cornea and conjunctiva are protected from damage. A number of possible eye drops for dry eyes are available, the main ingredient of which is a thickening agent, such as hyaluronic acid, which ensures that the substitute for the tears is not immediately washed away from the eye and flows away.
Other ingredients regulate the pH value, the salt content and adjust the values to the natural tear film. Often different products have to be tested before the optimal product for the individual sensations is found, because the effectiveness and tolerance can vary from person to person. An example of eye drops that are basically well tolerated and are purely herbal are the Euphrasia eye drops.
Allergies to preservatives or other ingredients of tear substitutes are rarely reported. However, a habituation effect can be excluded and thus the own tear production is not negatively influenced by the regular use of tear substitutes. Especially in case of frequent use (more than 5-6 times a day), sensitive eyes or wearing contact lenses, it is recommended to pay attention to preservative-free products, as they are especially gentle to the eyes and the material of the contact lenses.
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