Dry eye is a very common eye condition which consists of an alteration of the tear film with an incidence significantly increased in recent years and that is often underestimated in its importance.
The tear film is composed of three layers:
- Mucous, the innermost in direct contact with the corneal surface
- Aqueous, intermediate, the thickest of the three
- The outermost lipid and in direct contact with the external environment
Each of these layers has a specific role:
- I still firmly mucous layer the aqueous layer to the surface of the corneal cells, preventing it from slipping away
- The aqueous layer is the vehicle for nutrients, oxygen and contains many substances as a protective character as for example some immunoglobulins of the immune system.
- The lipid was used to limit the friction and evaporation, and must be continuously distributed on the surface by the eyelids because it tends to form blood cells as is the case with the fat suspended in a plate of broth.
Foto concessione: Dott. C. Benedetti
Dry eye is divided into two forms:
- Hypolacrimia: from reduced production of tears
- Dislacrimia: from excessive evaporation. This is the most common form.
The causes that contribute to determining the onset of dry eye are very numerous:
- Old age. Over the years there is an atrophy of the tear glands causing a progressive qualitative alteration of the tear itself.
- Menopause. In women who pass through this stage of life, due to hormonal imbalances, the lacrimal glands undergo a progressive atrophy.
- Contact lenses. Their prolonged use can greatly increase the evaporation of tears over that induce alterations of the ocular surface.
- Eyelid abnormalities. Chronic inflammation of the eyelid edge as blepharitis that, by affecting certain glands, may determine alterations to the composition of the tear film.
- Medications. Antidepressants, antihypertensives, antiarrhythmics, anti-ulcer, antihistamines, diuretics, hormones and immunosuppressants may inhibit the production of tears.
- Environmental factors. The constantly stationed in unhealthy environments due to air conditioning, excessive ventilation, high temperature, low humidity, work in furnaces …., Can turn a transient discomfort in a real pathological dryness
- Attention Activity. work or recreational activities requiring alertness such as computer work, video games, reading …., reduce the blink altering distribution favoring the evaporation of the tear film.
- Surgical and parasurgical Interventions. These transients can determine anatomical damage, and that can cause dry eye. In these cases a not timely therapeutic intervention may cause a chronicity of this state transforming it into a pathological dryness real.
The symptoms are numerous but all related to ocular surface alterations:
- Sensation of sand or foreign body in the eye
- Photophobia (sensitivity to light)
- Difficulty in opening the eyelids on awakening
- Feeling wet eye
- blink Difficulty
- Visual Fogging
The symptoms can be exacerbated by particularly unfavorable environmental conditions, such as exposure to wind, in the presence of smoke, air conditioning, heating or during use of mopeds or in the presence of smog.
The doctor can often observe the so-called red eye that is associated dry eye when you order established an inflammatory state.
The therapy is to substitute nature-based eye drops or gel by the action moisturizer and lubricant.
When, however, the dry eye is accompanied by inflammatory phenomena (gnawed eye), the use of a lubricant exclusively artificial and moisturizing tear may be insufficient. In this case the ophthalmologist will choose a product that combines lubricating and moisturizing effect also an anti-inflammatory particularly useful to reduce this complication.
It is necessary, therefore, a precise diagnosis by the ophthalmologist.