What is dry eye?

El Dry Eye is a process that affects the surface of the eyes, deterioration of the cornea and conjunctiva occurs due to poor wetting and lubrication of these structures, due to a scarce or poor quality tear but, really What is dry eye?.

It is known that dry eye is the most frequent ocular pathology, 20% of the population suffers it, increasing these values ​​to 40% in patients older than 60 years and reaching 68% in the case of women.

What is dry eye?

El Dry Eye is a process that affects the surface of the eyes, deterioration of the cornea and conjunctiva occurs due to poor wetting and lubrication of these structures, due to a scarce or poor quality tear but, really What is dry eye?.

It is known that dry eye is the most frequent ocular pathology, 20% of the population suffers it, increasing these values ​​to 40% in patients older than 60 years and reaching 68% in the case of women.

The dry eye

El Dry Eye It is a process that is characterized by Drying of the ocular surface. With each blink a tear film is formed that humidifies the eye for about 10 seconds, preventing us from having to blink continuously, something that would impede vision.

In people with dry eyes Early breakage of the tear film occurs and the air comes into direct contact with the ocular surface, resecting it and producing the death of the cells of the corneal-conjunctival epithelium together with an inflammatory reaction that still aggravates the situation, closing a vicious circle that advances the disease.

To understand the dry eye, it is necessary to analyze the three basic points that determine it:

  • Factors that cause tear deterioration.
  • Factors that start the tissue deterioration.
  • Alterations that occur in the eye such as consequence of deterioration of the tear

Dry eye is the most frequent ocular process and can affect up to 68% of the population in women over 60 years.

Before moving on to a more extensive explanation of what dry eye is, Dr. Carlos Vergés, director of our dry eye unit in Área Oftalmológica Avanzada, he explains it to us in this video.

The tear and the dry eye

To understand what dry eye is, it is important to keep in mind that: the direct contact of the air with the ocular surface determines changes in the cells of the surface of the eye (epidermal metaplasia), its metabolism is altered and its death and disappearance is accelerated.

On the other hand, the lack of tears means the loss of the natural lubricant and the rubbing of the eyelids on the eyes, a constant microtrauma that further aggravates the process of cellular resection, induces an inflammatory response with release of substances toxic to tissues, cytokines.

tear and dry eye

Currently we know that the deterioration of the tear, both when it comes to a quantitative deficit, as in the cases of alteration of its quality, is initially manifested by an increase in its osmolarity, of the particles that are dissolved in the watery part of the tear. Hyperosmolarity causes negative, toxic conditions, for ocular surface cells, initiating an inflammatory process that closes a vicious circle, alters the characteristics of the tear more and more, makes it evaporate more quickly and that air directly contacts the ocular surface and resects it.

In most cases of dry eye there is hyperosmolarity of the tear and inflammation of the tissues of the ocular surface.

Until now we thought that cases of dry eye were more frequent due to lack of tears, but it has been shown that cases with a tear of poor quality are more frequent or, as is still more frequent, a mixed mechanism, since in the majority of patients, the causative factors that we have seen before, occur in multiple ways. This is important because it changes the way of approaching diagnosis and treatment a lot, as we will see later.

  • In the dry eye there is a early tear film tear and the air directly contacts the eye surface, triggering tissue alteration, an epidermal metaplasia, which is aggravated by tear hyperosmolarity and secondary inflammation.
  • In most cases the alteration of the meibomian glands, main cause of early tear evaporationThat is why its study and treatment to solve the dry eye is essential.

Ocular surface and dry eye

The second important aspect to understand what is the dry eye is to know what is happening in the tissues as a result of ocular drying. We currently know that in all cases, regardless of the cause that originates it, there is an elevation of tear osmolarity and an inflammatory process. Hyperosmolarity acts as a toxic that damages the cells of the ocular surface and generates inflammation, which still contributes more to the deterioration of ocular surface cells.

It is essential to understand how hyperosmolarity and inflammation are added to the causative factors and advance the disease, further deteriorating the eyes and worsening the discomfort suffered by patients suffering from eye dryness.

In a practical way we can say that before a patient who consults us Dry Eye we establish a diagnostic plan based on:

  • Analysis of the causative factors.
  • Know the discomfort that the patient notices.
  • Osmolarity values ​​of the tear.
  • Inflammation level
  • Study of the efficacy of flickering, Meibomian glands and tear film stability.
  • State of involvement of eye tissues.

After establishing the dry eye causes, the alteration of tissues and the degree of evolution, we will be able to develop a specific and specific treatment plan for that person.

Meibomian glands

The meibomian glands play a major role in understanding what dry eye is. The importance of these glands in the problems of ocular dryness is already evident.

We can affirm that, in dry eye, in addition to deterioration of the ocular surface, there is a alteration of the meibomian glands.

These are glands found in the eyelids that are responsible for secreting lipids (fat), which combine with the tear, forming the most superficial layer of the tear film, preventing rapid evaporation. When these glands are altered, usually by obstruction of the exit orifice, there is no lipid secretion and the tear film breaks down within a few seconds and evaporates rapidly and exposes the ocular surface cells directly to the air.

The most recent studies on dry eye place special emphasis on the role of the meibomian glands in the genesis of the disease. The alteration of these glands would be in the 80% of cases of dry eye, hence the importance in being able to study them to assess their status.

The clinical manifestation of the dry eye is the appearance of the typical discomfort of sand or foreign body sensation, especially in the mornings, discomfort that increases in closed, dry environments, with air conditioners or strong heaters or on very windy days . 

dry eye that is
  • Patients with dry eye complain of discomfort when opening their eyes in the morning and have gritty or burning sensation, of variable course, throughout the day.
  • It is common for these patients to have fluctuating vision and present difficulty or impossibility in front of tasks that require fixing the view such as reading, computer, smartphones, any activity that involves fixing the view.
  • In most cases there is a feeling of frustration and anxiety seeing how the disease does not end and does not let them perform their daily tasks, aggravated by the misunderstanding of the people around them.

The importance of dry eye

Patients suffering from these alterations, especially in cases with significant daily activity, can pose a very serious problem. The consequences of ocular dryness, among others, is a decrease in work capacity, generates insecurity and can reach a situation of significant frustration, worsening with a sense of incomprehension regarding the people around them.

In some cases it is necessary to explain to the relatives the problem that the dry eye supposes, so that they can help the sufferer.

En Área Oftalmológica Avanzada We are specialists in the diagnosis and treatment of this disease. If you suffer from this condition, do not hesitate to come and visit us.

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What is dry eye
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What is dry eye
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We explain what is the dry eye to detail and what are the causes of this disease. Only if we can understand the dry eye will we be able to cure it.
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Área Oftalmológica Avanzada
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