Dry eye

Dry eye is a process characterized by the desiccation of the ocular surface. With each blink, a tear film which moistens the eye for about 10 seconds is created, preventing us from the continuous blinking, which would disturb our vision.

A premature rupture of the tear film is produced in people with dry eye and the first consequence is the air coming into direct contact with the ocular surface, resulting in dryness and the death of cells found in the corneal-conjunctival epithelium, as well as an inflammatory reaction that makes the situation even worse, closing a vicious circle that feeds the disease.

Dry eye is known as the most common eye disease since a 20% of the population suffers from it, plus these values increase to a 40% in patients older than 60 years and reaching 68% in the case of women that age.

To understand dry eye is necessary to analyze the three basic points that determine this disease:

  • Factors causing deterioration of the tear.
  • Factors that initiate tissue damage.
  • Changes that occur in the eye as a result of the deterioration of the tear.

Nowadays, we can be confident when saying that there are multiple factors which can cause tears disorders and we are aware of how complex it is to know all of those disorders affecting the patients thoroughly, so this is why we say that dry eye is a multifactorial disease. What we have learnt over the last years is how important is to do a thorough research of these causative factors, which will let us at least try to control and eliminate those, as far as possible, if we want to solve the disease.

  • Dry eye is the most common ocular process and may affect up to 68% of the population: women over 60years.
  • In most cases of dry eye coexist tear hyperosmolarity and inflammation of the ocular surface.

The second important aspect is to know what is happening in the tissues as a result of ocular dryness. We now know that in all cases, regardless of the cause, there is a rise in tear osmolarity and an inflammatory process. Hyperosmolarity acts as a toxic factor, damaging the cells of the ocular surface and creating inflammation, which still further contributes to the deterioration of the ocular surface.

The third important aspect is to watch out how hyperosmolarity and inflammation are added to the causative factors, further eroding the eyes and worsening discomfort experienced by patients suffering from dry eye.

In practical terms we can say that, in a patient who complains of dry eye, we establish a diagnosis plan, based on:

  • Analysis of the causative factors
  • Patient symptomatology
  • Tear osmolarity
  • Level of inflammation
  • Study of the effectiveness of blinking, meibomian glands and tear film stability
  • State of ocular tissues

Once established the causes, the tissue impairment and the degree of evolution, we can develop a specific treatment strategy.