The dry eye syndrome (also called keratoconjunctivitis sicca) refers to ocular dryness that affects the cornea and conjunctiva. The DEWS report (Dry Eye Workshop) defines the dry eye syndrome as a multifactorial disease of the tears and ocular surface, which is characterized by symptoms such as ocular discomfort, visual disorders, tear film instability which may lead to an alteration of the ocular surface.

Prevalence: 3 to 15%, even 35% in the population aged over 50.

The cause of dry eye syndrome is a lack of eye humidification, produced for various reasons: dry atmosphere, wind, prolonged use of contact lenses, poor eye blinking (most important for people working at the computer), the effect of general diseases (e.g. rheumatoid arthritis, lupus, Sjogren syndrome), the side effect of using certain medicines, etc. This condition can also occur as a result of the lacrimal gland aging.

Individuals operating in dusty environments, cigarette smoke, low humidity or air conditioners are prone to dry eye syndrome.

Tears are composed of three layers:

• The outer layer (lipidic)
• The middle layer (aqueous)
• The inner layer (mucinous, mucous)

The lacrimal gland produces the aqueous layer. A problem with any of these layers can lead to dry eye.

The symptoms are relatively mild in the early stages of the disease, but they worsen with the disease progression. They may be exacerbated by prolonged visual effort: reading, driving or prolonged use of a computer screen because, in such cases, we tend to blink less often than we normally do.

• sensation of “sand in the eyes” (or foreign body sensation)
• difficulty in opening the eyelids in the morning, sometimes followed by chronically watery eyes
• sensitivity to light, sometimes, temporary blurred vision
• dryness, sometimes inability to cry (to produce tears)
• red eyelids and conjunctivitis, sometimes filamentous secretions

Aqueous tear deficiency:

1. primary / secondary Sjogren's syndrome

- Primary: salivary and lacrimal glands are targeted by an autoimmune inflammatory process

- Secondary: in other autoimmune diseases

      2. Non - Sjogren “dry eye” syndrome

a) condition of the lacrimal gland - primary / secondary

b) obstruction of the main and accessory lacrimal gland duct (trachoma, scar pemphigus, burns)

c) reflex hyposecretion due to the sensory or motor reflex block

The sensory reflex is affected especially after surgery (e.g. cataract, refractive surgery, contact lens wear, age).

       3. The secretomotor function is affected by facial nerve injury, when lagophthalmos occurs.

Dry eye syndrome caused by the tear evaporation:

a) intrinsic

• Meibomian gland dysfunction (posterior blepharitis)
• abnormalities of the palpebral fissure: exophthalmia.
• decreased blink rate: Parkinson’s, looking at the computer screen or through the microscope for a long time

b) extrinsic:

• impairment of the ocular surface: vitamin A deficiency, the local effect of preservatives (antiglaucomatous medication)
• wearing contact lenses
• chronic allergic conjunctivitis

• Clinical history
• Composition of the tear film
• Tear film stability
• Ocular surface: colour, cytology, surface microscopy

• In the cabinet the following are often used:

• Tear Fluorescein Break-Up Time (TFBUT) - Normal> 15 sec
• Schirmer’s test
• LIPCOF score (at biomicroscope) - conjunctival mucosa dryness indicator

• Educating patients (increased ambient humidity, goggles, taking breaks when working on the computer, avoiding exposure to air-conditioning)
• Artificial tears (preferably preservative-free formulations)
• Gels, eye ointments - for more severe forms
• Anti-inflammatory agents (non-steroidal / steroidal)
• Tetracycline (in case of chronic blepharitis, rosacea)
• Temporary / permanent occlusion of the lacrimal points
• Immunosuppressants (cyclosporine)
• Essential fatty acids (Omega 3) - dietary supplements
• Therapeutic contact lenses (in case of corneal ulceration)