Dry eyes

Dry eyes are caused by insufficient tear production or a tear film that evaporates too quickly. This can cause eyes to burn and sting, to secrete mucus and sometimes to become red. The vision may be variable and you may experience problems with the light.

What is the tear film?

To protect your eyes from drying out, blink your eyes. This goes unnoticed and you do this up to about 15 times per minute. Each time, a particularly thin layer of tear fluid is evenly distributed over the eye: the tear film. The tear film keeps the eye moist, lubricated and protects the cornea.

The tear film is made up of three layers:

  • The outer layer: a fatty layer produced by small sebaceous glands in the eyelid margin, the Meiboom glands. This layer prevents the tear fluid from evaporating (too quickly).
  • The middle layer: an aqueous layer produced by the lacrimal gland in the eye socket. This layer ensures that the eye remains clean of dirt and dust.
  • The inner layer: a mucous layer produced by small glands in the conjunctiva of the eye that ensures that the aqueous layer spreads evenly over the eye and adheres well to it.

There are several factors that can disrupt this.

Causes

In general, we distinguish dry eyes as a result of too low tear (water) production and too rapid evaporation of the tear film. Mixed forms of both of these main causes are very common.
Various factors may underlie this:

  • (Older) age: as one gets older, one often suffers more from dry eyes, due to both less tear production and faster evaporation.
  • Meibomian gland dysfunction leads to faster evaporation of the tear film due to insufficient quality of the oily layer.
  • Allergy mainly affects the Meibomian glands and therefore the quality of tears.
  • General physical situations or conditions, such as hormonal abnormalities (including thyroid diseases and diabetes mellitus) or changes (pregnancy, menopause (menopause), these factors also mainly influence the Meibomian glands and evaporation.
  • Scars in the cornea, as a result of which the tear film is less evenly distributed over the cornea and does not reach all surfaces properly, thus insufficiently protecting the eye from drying out.
  • Damage to the sensory nerve of the eye (e.g. after infections such as Herpes or shingles).
  • There are several environmental factors that can cause dry eyes. Examples of this are: dry air (air conditioning, central heating), strong air currents (driving with an open window), smoke and dust, screen work, use of certain medicines and contact lenses.
  • Excessive tear film evaporation can occur when the eyelids do not blink properly, causing the tears to not be spread properly or often enough over the surface (e.g. in Parkinson’s disease) and when an eye does not close properly (e.g. in case of a facial paralysis).

Diagnosis

The ophthalmologist must first determine the cause of the dry and/or watery eyes before he or she can start treatment. This is not always easy. During the examination period, the ophthalmologist will take measures to reduce the irritation caused by dry eyes as much as possible.

Forecast

Dry eyes are usually a (serious) discomfort. Only in exceptional cases can they lead to poor visibility.

Treatment

The treatment often consists of the use of artificial tears (in a drop or gel form). For many patients, the daily use of these is cumbersome and/or disruptive. There is also the possibility of placing punctum plugs in the tear duct drainage, so that the own tear fluid remains on the eye better/longer. In that case, it is usually no longer necessary to use drops and there are no more significant complaints of dry eyes. If necessary and/or desired, the plugs can simply be removed again. The treatment with plugs is performed at our clinic.

to Dry Eye Treatment