One of the most popular problems in ophthalmology is the dry eye syndrome. About 16 million people in the Earth are affected by this syndrome. Dry eye syndrome is more than 6% in people over 40 years old and around 15% in those over 65 years. Its distribution varies between regions. In adults, dry eye symptoms reported: 14.5% in the USA, 33.7% in Taipei (Taiwan), 25% in Germany. With the revolution of technological processes, the syndrome deepens and increases. Dryness in the eye affects over 20% of the population of Bulgaria. Dry eye syndrome is a condition associated with reduced production or accelerated tear evaporation or a disturbed proportion in the components of the tear film. It is also called dry keratitis and is associated with insufficient moisture on the surface of the eyeball. Tears help the eyes moisture and protect the eye surface. Dry eye is a condition caused by changes in the quantity or quality of the tears, resulting in dryness and irritation in the eyes. Normally, the tears „bathe“ the eye by removing dust and other small foreign particles, keeping it moist all the time. Tears contain enzymes that neutralize the microorganisms normally living in the eye. In other words, tears are necessary for the „health“ of the eye. Dry tears do not produce enough tears or are poor and faster than normal evaporation.

І. DIAGNOSTICS

Schirmer’s test, because of its low cost and ease of application, is the most commonly used objective diagnostic method for dry eye syndrome. Only tear output is measured, and the aspects associated with tear evaporation are ignored. For the diagnosis of „dry eye“ staining of the surface tissues of the eye with different dyes is used. The tear time of the tear film is examined, the tears being stained with fluorescein. The test is done by an ophthalmologist on a biomicroscope with a special blue filter.

ІІ. SYMPTOMS

Dry eye complaints range from pain, irritating sensation or burning of the eyes, dryness, itching, burning, feeling of a foreign body, soreness, blurred vision, irritation from light, eye fatigue, general discomfort. Tears are often observed. Complaints increase at the end of the day, usually exacerbated by sudden climatic changes, staying in air-conditioned rooms, prolonged viewing and improving after eye closure. Prolonged irritation endangers vision. An inflammation may occur that may damage the cornea of the eyes.

ІІІ. CAUSES

Dry eye may be the result of both systemic diseases and pure eye trauma. The leading reasons are:

• dust, smoke
• work with a computer (especially daytime workers are endangered)
• central heating
• cosmetics
• old age
• menopause
• contraceptives
• systemic autoimmune diseases
• taking a wide range of medications
• hypovitaminosis
• eye trauma
• burns
• use of contact lenses
• inflammation of the conjunctiva and cornea
• nervous disorder
• dry environment
• Age
• hormonal changes.
• Homeopathic medicines may have an adverse effect on dry eye conditions.
• Loss of corneal sensitivity by long-term contact lens wear may cause dry eyes.
• Dry eyes may be associated with disorders of the immune system, such as Sjögren’s syndrome, lupus and rheumatoid arthritis. Sögren leads to inflammation and dryness of the mouth, eyes and other mucous membranes.
• • Dry eyes may be a symptom of chronic conjunctival inflammation.

Regardless of the reason, all dry eye patients have a change in the quantity and quality of the tears. This results in reduced tear exchange, increased osmolarity, eye irritation, inflammatory cytokine production. The end result is inflammation. Once started, inflammation leads to damage to the eye structures, which maintains and enhances the vicious circle of irritation and further inflammation.

Winter activates Dry Eye Syndrome
Dry eye syndrome worsens in winter because of the cold, dry air outside, as well as inside the hot rooms.

ІV. TIPS FOR PREVENTION

In addition to frequent visits to an ophthalmologist, a number of things can be done to prevent, alleviate or eliminate the symptoms of a „dry eye“.
First, care for yourself and your own health:

• regular walking or exercising at fresh air
• Take at least 2 liters of fluid daily
• Including many vitamins in your daily diet
• Providing enough hours of sleep.

Second, prevent drying of your eyes:

• Do not target the fans directly to the face (in the car, in the airplane, etc.)
• Use safety glasses when skiing, cycling or swimming
• Do not smoke and avoid smoky spaces
• avoiding air conditioners
• using humidifiers in the air
• keep the contact lenses wet.

 Thirdly, when working on a computer:

• Working in daylight, but not in direct sunlight
• or using bright but not dazzling artificial light
• avoiding reflections on the monitor screen
• Working at a distance of 50-70 cm from the screen
• frequent blinking and regular short breaks.

V. TREATMENT

Methods for treating dry eye vary depending on the severity of the condition: application of artificial tears, gels, moisturizing chambers. In the most severe cases, synthetic obturators of the tear ducts are implanted to store the little self-made tear. According to some studies, topical administration of cyclosporine (prescribed by a doctor), which increases the natural production of tears and leads to improvement of dry eye syndrome, whether it is expressed in a low, medium or severe degree. The topical use of alpha-linolenic acid, the omega-3 fatty acid group, has a positive effect in resolving the symptoms of the underlying inflammatory changes in dry eye syndrome. Omega-3 fatty acids are contained in fish, so it is advisable to eat fish and, above all, salmon or fish oil. Hot compresses also apply – put on a warm, damp cloth for 10 minutes on the eyelids once a day.

Washing of the eyelid margin of the eyelids is performed with a combination of dry eye syndrome and blepharitis. Also hydroxypropyl cellulose (Lacrisert), which is placed in the lower inner corner of the eye. Experimental studies are conducted on the positive effect of zipkins on dry eye syndrome. In the absence of treatment with conservatively treated, surgical methods are applied, in which the tear ducts are closed operably, which prevents the tears from going into the nose. In some cases, a simple operation called punctal burning is recommended to close the drainage holes. At the experimental stage of development, chemokine receptor-2 (CCR2) antagonists are present. The treated eyes of animal models (mice) show a reversal of corneal epithelial damage manifested by a decrease in corneal staining with fluorescein. This is most likely due to decreased expression of proinflammatory cytokines.

There is also a new, liposome therapy to treat the dry eye The last years of the market a new liposomal product for dry eye in the form of an eye spray. It contains liposomes from soy lecithin, as well as vitamins E and A. The spray avoids the inconveniences associated with the application of traditional dry eye drops as it is sprayed onto closed eyelids, lipid liposome blends along the eyelid edge with the natural lipids of the tear film and stabilizes it Advantages of the liposome spray for „dry eye“ are:
• Extremely easy to use
• Splashes on slightly closed eyelids and does not drip into eyes
• Complaints such as irritation, burning and feeling of a foreign body disappear immediately after use
• Stabilizes tear film up to 4 hours
• Recommended using contact lenses. Contact lenses do not need to be removed
• Suitable in hot months – dry air, air conditioning, office, car • Natural product. Contains no preservatives
• Very good tolerance. No side effects are known
• Economical – one pack is about a month for 3-4 applications a day.
• There is no residual time after first use.
• Can be used by several people at the same time, as there is no danger of contamination
• Can be used even with applied makeup.

Clinical trials demonstrate the effectiveness of liposomal spray

Clinical studies show very good results from liposome spray applications in dry eye treatment. In 85% of liposome sprays, there was a significant improvement in lacrimal film rupture, inflammation of the eyelid edge (89.5% decrease) and improvement in visual acuity. 93% of participants rated the liposome spray as „good or very good“, and 94.5% rated the use of a spray as more convenient and enjoyable than previously used „dry eye“ drops. „.Compared to traditional eye drops and gels, the use of spray significantly reduces the risk of infections and mechanical damage to the eye.

VІ. DRY EYE SDYNDROME IN WINTER

For dry eye syndrome, during the winter to avoid exacerbating complaints, the following recommendations may be made: • wear sunglasses to reduce exposure to sun, wind and dust • use air conditioners to clean the air and • heating use a moisturizer or a water tank to evaporate

VІІ. DRY EYE SYNDROME IN WOMEN

Women are more likely to suffer from dry eye, according to a random survey among 5650 people in Sofia. The presence of dry eye condition is more common in women due to monthly „stormy hormonal changes”. With age, symptoms increase and deepen.  Approximately 14 percent of those tested for „dry eye“ have a high probability of eye dryness and 45.48 percent are borderline. This means that about 60 percent of those surveyed have a high risk of having a dry eye. Only 27.23 percent of those who have a high risk of having a dry eye know that they have such a problem. Three out of four respondents report using a computer, which is one of the main risk factors for the appearance of a „dry eye“. By the age of 50, the production of tears in man is decreasing, and by the age of 75, almost all people suffer some degree of dry eye.

Assoc. Prof. Krassimir Koev, Ph.D. Medical University of Sofia