Dry Eye Syndrome - Causes, Symptoms, Effects And Treatment Of Dry Eye Syndrome

2024 Author: Josephine Shorter | [email protected]. Last modified: 2024-01-07 17:49

Causes, symptoms, consequences and treatment of dry eye syndrome

Content:

• What is dry eye syndrome?
• Causes of dry eye syndrome
• Symptoms of dry eye syndrome
• The consequences of the development of the syndrome
• Dry eye treatment

What is dry eye syndrome?

Dry eye syndrome (xerophthalmia) is a pathological condition characterized by insufficient hydration of the cornea and conjunctiva of the eyes due to instability of the tear film and lack of tear fluid.

The anterior surface of a healthy eye is covered with an intact tear film approximately 10 µm thick.

This film protects the eyes from negative environmental influences, dust and other small foreign bodies, and also supplies the cornea with nutrients and oxygen, creating a natural immune barrier against infections.

The tear film consists of 3 layers:

• Mucin layer - produced by the goblet cells of the conjunctiva and covers the cornea, making its surface smooth and even; its function is to keep the tear film on the corneal epithelium; the thickness of this layer is 0.02-0.05 microns, this is only 0.5% of the film thickness;
• Aqueous (watery) layer - produced by the lacrimal glands and consists of biologically active substances and dissolved electrolytes; continuously renews and supplies the corneal and conjunctival epithelium with nutrients and oxygen, and also ensures the removal of carbon dioxide molecules, metabolic waste and dead epithelial cells. The thickness of this layer is about 7 microns, which is more than 90% of the tear film;
• Lipid layer - covers the outside of the aqueous layer and is produced by the meibomian glands; is responsible for the sliding of the upper eyelid and protection of the eyeball, prevents the evaporation of the aqueous layer and excessive heat transfer of its epithelium.

On average, once every 10 seconds, the tear film breaks, prompting blinking, resulting in tear fluid renewal and film rebuilding. Moving along the surface of the cornea, the eyelid evens out the tear film and cleanses the cornea of exfoliated epithelial cells and foreign inclusions. At the same time, blinking stimulates the production of tear fluid by the glands.

Within one minute, about 15% of the entire tear film is renewed, and 8% is evaporated. Dry eye syndrome occurs when multiple tears of the tear film occur frequently, resulting in excessive dryness of the cornea. The reasons for such ruptures can be various factors: too rapid evaporation of the film, impaired secretion of mucins, lipids and lacrimal fluid.

This syndrome is diagnosed in 10-20% of the population, and is more common in women (70% of cases). The frequency of the disease is in direct proportion to age: only 12% of cases fall by the age of 50 years. 42-43% of people with this syndrome notice a significant deterioration in vision, have difficulty reading.

Causes of dry eye syndrome

The syndrome develops with a lack and low quality of tear fluid. The reasons for this may be some diseases:

• Autoimmune (connective tissue diseases, Sjogren's syndrome);
• Endocrine (endocrine ophthalmopathy);
• Diseases of the hematopoietic system (malignant lymphoma);
• Neurological (Parkinson's disease);
• Infectious;
• Kidney pathology;
• Skin diseases of autoimmune etiology (pemphigus).

In diseases of the connective tissue, its pathological proliferation leads to blockage of the excretory ducts of the lacrimal glands. With Sjogren's syndrome, the lacrimal glands themselves are affected, not only a deficiency of the lacrimal fluid occurs, but also its composition changes: it becomes more viscous and thick, loses its bactericidal properties. Concomitant symptoms of Sjogren's syndrome are dry mouth and genitals, swelling of the salivary glands, and joint pain.

A separate group can be distinguished directly by pathologies of the organs of vision of an inflammatory and other nature, as well as surgical interventions leading to destabilization of the tear film:

• Chronic conjunctivitis;
• Neuroparalytic and neurotrophic keratitis;
• Lagophthalmos;
• Corneal surgery and radial keratotomy;
• Blepharoplasty.

Lagophthalmos is a pathology in which the eyelids do not close completely. For even lubrication of the eyeball with tear fluid, it is necessary that the eyes are completely closed.

After blepharoplasty, 25% of patients experience dry eye symptoms.

The risk group includes people exposed to the following factors:

• Long-term work at the computer, reading, watching TV, working with small details;
• Exposure to dry warm air from heating systems and air conditioners;
• Wrong choice and wearing of contact lenses;
• Poor environmental situation (in people living in megacities, in conditions of polluted air, dry eye syndrome is observed 4 times more often than in rural areas);
• Avitaminosis, depletion of the body;
• Long-term use of certain medications;
• Genetic predisposition;
• Decreased frequency of blinking movements for centuries.

Also, this can include the climacteric period and pregnancy in women, since the dependence of the onset of dry eye syndrome on the level of estrogen in the blood has been revealed.

Dry air of heating systems provokes accelerated evaporation of liquid from the surface of the eyeball, therefore this syndrome is more typical for residents of cold climatic zones. Prolonged visual concentration on certain objects (monitor screen or other objects) leads to insufficient blinking frequency. Also, too rare blinking may be due to a decrease in the sensitivity of the cornea. Wearing contact lenses can significantly increase dry eyes.

Certain medications reduce tear production. These include: hormonal contraceptives, corticosteroids, anesthetics, anticholinergics, antihistamines, and blood pressure medications.

Symptoms of dry eye syndrome

Symptoms are bilateral (that is, they appear immediately in both eyes).

Subjective symptoms include:

• Dryness of the cornea;
• Feeling of a foreign object, "sand in the eyes";
• Itching, burning, cramps (when the tear film breaks, the sensitivity of the cornea increases, the risk of allergic reactions increases);
• Redness of the eyes (often dry eye syndrome is accompanied by the development of an inflammatory process, since the damaged tear film does not fulfill its bactericidal function);
• Sticking eyelids after sleep;
• Blurred vision that disappears when blinking (renewal of the tear film eliminates its irregularities, which cause blurred images);
• Lachrymation;
• Photophobia (increased sensitivity to light);
• Painful sensations, especially when the eyes are buried.

Often these symptoms appear in an erased form. They intensify when exposed to dry and dusty air, in smoky rooms, in strong winds, after prolonged eye strain.

The objective signs of the syndrome are:

• Reduction or disappearance of lacrimal menisci at the edges of the eyelids (which is a sign of moderate corneal-conjunctival xerosis);
• Formation of conjunctival secretions in the form of threads of mucus;
• Weak conjunctival hyperemia.

Signs such as burning, stinging, sensation of a foreign body in the eye, lacrimation and photophobia are non-specific, that is, they are observed in some other eye diseases, but are also taken into account when making a diagnosis.

The consequences of the development of the syndrome

Even a mild form of dry eye syndrome requires adequate medical treatment to prevent serious and irreversible consequences, which may include the following:

• Infection of eye tissue;
• Corneal damage
• Formation of various erosion;
• Partial or complete loss of vision.

Preventive measures consist in limiting the impact of external negative factors, timely treatment of internal diseases, rational nutrition and drinking a sufficient amount of liquid.

On the subject: Vitamins for the eyes - which are the best?

Dry eye treatment

The diagnosis is made based on the results of biomicroscopy, tear analysis, conjunctival smear cytology, Schirmer's and Norn's tests (which determine the rate of formation and evaporation of the tear film). For treatment, artificial tear preparations are used, in some cases - surgical methods.

Eye drops

High viscosity products include Vidisik, Oftagel, Lakropos, Korneregel. During blinking, the gel consistency of the drops liquefies and moisturizes the cornea. Gels are placed behind the eyelid and are applied for a long time, once every 1-2 days.

To relieve inflammation, which often accompanies dry eye syndrome, antibiotics and immunosuppressants can be prescribed: ointment with erythromycin or tetracycline (course of 7-10 days), Restasis drops with cyclosporine, as well as hormonal drops Maxidex, Alrex, Oftan, Dexamethasone.

Surgery

The following methods are used as surgical treatment:

• Obstruction of the tear ducts (blockage with special microscopic silicone plugs for the accumulation of fluid on the surface of the cornea);
• Corneal plastic surgery (performed for xerotic ulcers, perforation and corneal necrosis);
• Lateral tarsorraphy (performed with lagophthalmos);
• Transplantation of the salivary glands into the conjunctival sac.

The author of the article: Degtyareva Marina Vitalievna, ophthalmologist, ophthalmologist