Dry eyes (dry eye syndrome)

Dry eyes (Sjögren's syndrome) is a chronic disease with a primary lesion of lacrimal and salivary glands. The "dry eye" syndrome develops slowly and proceeds chronically with periods of remission and exacerbation with a lack of tear fluid entering the conjunctival bag to moisten the anterior wall of the eyeball. As a result, the conjunctiva and the cornea dry periodically, which leads to an unpleasant sensation of dryness, rubbing, itching and sensation of the foreign body under the eyelids, photophobia, poor tolerance of wind, smoke. All these symptoms of dry eyes deteriorate towards evening.

[1], [2], [3], [4]

Causes of the dry eyes

The causes of development of dry eyes are unknown. In some patients, signs of rheumatoid arthritis or other symptoms of connective tissue damage are revealed. Women are more often (90%) aged over 40, usually with the onset of menopause.

What causes dry eyes?

Symptoms of the dry eyes

Dry eyes have the following symptoms - irritation, foreign body sensation, burning, mucilage filamentous discharge and periodic "misting". Less frequent symptoms of dry eyes - itching, photophobia and fatigue or a feeling of heaviness in the eyes. Patients with filamentous keratin may complain of severe pain when blinking. Patients rarely complain of dry eyes, although some may note a lack of emotional tears or an inadequate response of tearing to a stimulus (for example, onions). Symptoms of dry eyes are often exacerbated by external factors associated with increased evaporation of tears (for example, wind, air conditioning, central heating), or with a very long reading, when the frequency of blinking movements decreases significantly. Symptoms of dry eyes also decrease with closed eyes.

Impaired tear film

The early sign of dry eyes is the threads of mucin. Normally, when a tear film is ruptured, the mucinous layer is mixed with the lipid layer, but quickly washed off. In the "dry" eye, mucin mixed with the lipid layer begins to accumulate in the lacrimal film and shifts when blinking. Funny feature of mucin - it dries very quickly and very slowly rehydrates.

Marginal lacrimal meniscus is a measure of the volume of the aqueous layer in the lacrimal film. Normally, the volume of the meniscus varies in height from 0.1 to 0.5 mm and forms a convex strip with the right upper edge. With dry eyes, the meniscus can acquire a concave shape, become uneven, thin, or absent.

Foamy discharge in the lacrimal film or along the edge of the eyelid is observed in the violation of the function of meibomian glands.

[5], [6],

Keratopathy

Spot epitheliopathy captures the lower half of the cornea.

Corneal filaments consist of small, comma-shaped lumps of mucus at the level of the epithelium. Attached one end to the surface of the cornea; The free end moves when flashing.

Filamentous infiltrates are translucent, white-gray, slightly protruding formations of various sizes and shapes. They consist of mucus, epithelioid cells and protein-lipid components. They are usually identified with mucous threads when stained with Bengal pink.

It must be remembered that the "dry" eye promotes the development of bacterial keratitis and frequent ulceration, which can lead to perforation.

Stages

There are 3 stages of eye damage: hypoxia of the lacrimal fluid, dry conjunctivitis, dry keratoconjunctivitis. In connection with eye irritation in the first stages of the disease, tearing reflex increases, which can be accompanied by a clinical picture of hypersecretion of tears - stasis of tears and even lacrimation. In the longest, the discharge of tears with eye irritation sharply decreases, with tears in the crying absent. In the conjunctival sac, a viscous filamentous secret is found, consisting of tears and sloughing epithelial cells. The conjunctiva is mildly hyperemic, papillary hypertrophy is often observed along the upper edge of the cartilage. Superficial, small and variable forms and turbidity forms, stained with fluorescein, appear initially in the lower half of the cornea, and later - throughout the cornea. "Dry eyes" are prone to progression, possibly damage to other organs and body systems: dry mouth, nasopharynx, genital organs, chronic polyarthritis, and later - violation of the liver, intestines, cardiovascular system and organs of the genitourinary system.

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Diagnostics of the dry eyes

When performing the diagnosis of "dry eyes", it is necessary to take into account the patient's characteristic complaints, the results of biomicroscopic examination of the eyelid, conjunctiva and cornea edges, as well as specific tests.

Special studies with dry eyes

• A standard test is a test evaluating the stability of a tear film. When looking down in a drawn-out century, a 0.1-0.2% solution of fluorescein is added to the limb region for 12 hours. After switching on the slit lamp, the patient should not be blinking. Diagnostic value is the time of rupture of the tear film less than 10 seconds.
• A sample of Schirmer with a standard strip of filter paper, one end inserted at the lower eyelid. After 5 minutes, the strip is removed and the length of the moistened part is measured: its value less than 10 mm may indicate a slight decrease in the secretion of tear fluid, and less than 5 mm - about a significant.
• The sample with a 1% Bengal pink solution is especially informative, since it allows to determine the dead (colored) epithelial cells that cover the cornea and conjunctiva.

Diagnosis of "dry eye" involves some difficulties and is based only on the result of a comprehensive assessment of patient complaints and symptoms, as well as the results of functional tests.

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Time of rupture of tear film

The time of rupture of the tear film is an indicator of its stability. It is measured as follows:

• fluorescein is instilled in the lower conjunctival arch;
• the patient is asked to blink several times and then do not blink;
• a tear film is examined in a wide section of a slit lamp with a cobalt blue filter. After a while, you can see ruptures of tear film, indicating the formation of dry areas.

Take into account the time between the last flashing and the appearance of the first randomly located dry areas. Their appearance always in one place should not be taken into account, since this is not caused by instability of the tear film, but is a local feature of the relief of the cornea. The appearance time of dry areas in less than 10 seconds is a deviation from the norm.

Bengal pink

Used to color non-viable epithelial cells and mucin. Bengal pink stains the altered bulbar conjunctiva in the form of two triangles with their bases to the limbus. Corneal threads and infiltrates also stain, but more intensely. The disadvantage of Bengal pink is that it can cause prolonged eye irritation, especially with a pronounced "dry" eye. To reduce irritation, a small amount of drops can be used, but local anesthetics should not be used before instillation, because they can cause a false positive result.

[12], [13], [14], [15]

Schirmer Test

Applied in the case when a lack of tear fluid without biomicroscopic signs of a dry eye is assumed. The test consists in measuring the moistened part of special paper filters 5 mm wide and 35 mm long (No. 41 Whatman). The test can be performed with or without local anesthesia. In the test without anesthesia (Schirmer 1), the total, primary and reflex tear production is measured, and with the use of an anesthetic (Schirmer 2), only the main secretion is measured. In practice, local anesthesia reduces reflex secretion, but does not completely eliminate it. The test is carried out as follows:

• gently remove the existing tear;
• The paper filter, bent at a distance of 5 mm from one end, is placed in the conjunctival cavity between the middle third and outer third lower eyelid, without touching the cornea;
• the patient is asked to keep his eyes open and flash as usual;
• After 5 minutes, the filters are removed and the amount of humidification is evaluated.

The normal result is more than 15 mm without anesthesia and slightly less with anesthesia. The range between 6 and 10 mm is the normal limit, and a result of less than 6 mm indicates a decrease in secretion.

Treatment of the dry eyes

Treatment of dry eyes presents great difficulties. Individual selection of medicines is necessary.

Recommend:

• constant instillation of artificial tears;
• at night appoint a disinfectant ointment or eye gel solkoseril or Actovegin;
• eliminate the cause that caused "dry eyes" (treatment of the underlying disease);
• avoid prolonged stay in dry and hot areas;

If necessary, enter special obturates into the lacrimal canaliculi or perform occlusion of lacrimal points by surgical methods.

Treatment of dry eyes