Dry eyes: symptoms, syndrome and treatment
Dry eyes (dry eyes, dry eye syndrome) is a condition of the eyes that occurs when there is insufficient moisture and/or lubrication of the outer surface of the eye with a tear fluid or just a tear. With dry eyes, there is a feeling of “sand in the eyes”, eye irritation, “burning”, “pain” in the eyes.
Usually, elderly people suffer from dry eyes. Recently, however, dry eyes often occur in young people who spend a lot of time on computers. Users of contact lenses can feel dry eyes in a room with air conditioning, when working at a computer, when in dry air, in strong winds, and in other adverse conditions for the eyes.
In order to eliminate the symptoms of dry eyes, artificial tears are usually used, for users of contact lenses special moisturizing/lubricating drops are produced.
Dry eye syndrome
Dry eye syndrome occurs when the surface of the eye is poorly moistened and lubricated. Moisturizing and lubrication of the eye are provided by a tear film, which forms a tear fluid on the surface of the eye. Thinning of the tear film or violation of its composition leads to drying of the cornea, there is a feeling of dryness, eye irritation. The eye becomes extremely sensitive to dry air, to the wind, to cigarette smoke. Disturbance of normal moisturizing and blurring of the eyes can occur for various reasons.
The structure of the tear film
The tear film consists of 3 layers. The main middle layer is a watery layer consisting of 98% water and containing proteins and salt in addition to water. The watery layer is what we usually call the tears that appear when we cry or laugh. The watery layer is created by the lacrimal glands, located above each eye at the outer edge. The lacrimal glands constantly emit a small amount of tear fluid, which, when blinking, is evenly distributed over the surface of the eye
Small glands located at the edges of the eyelids (meibomian glands) secrete fats (lipids) that make up the outer layer of the tear film. The lipid layer prevents the evaporation of moisture from the main aqueous layer, serves as a protective barrier and gives the surface of the tear film smoothness, thereby providing conditions for proper refraction of light rays when passing through the tear film.
The conjunctiva (a thin transparent shell covering the inner surface of the eyelid and, with a transition to the eye, the sclera of the eye (the “white” eye area)) releases a small amount of mucous substance (mucin). The mucin layer smoothes all the irregularities of the surface of the cornea and promotes a uniform distribution of the tear fluid over the surface of the eye.
Having washed the outer surface of the eye, the lacrimal fluid is drained through the lacrimal canaliculi into the so-called lacrimal sac, and then into the nasal cavity.
Dry eyes factors
Dry eyes can occur in anyone, but more often it occurs in old age. It is believed that dry eyes appear in approximately 7% of people aged 50-60 years and 15% in the age of 70 years and older. And women experience dry eyes more often than men.
Age. With age, our eyes emit less tear fluid, and it is not enough for normal wetting of the eye. The composition of the tear film also deteriorates. Lack of tear fluid and violation of its composition are manifested in adverse environmental conditions (dry air, smoke, etc.).
Medicines. Some drugs with prolonged use have as a side effect dry eyes or aggravate the already existing state of dryness. These drugs include diuretics (diuretic drugs), some antidepressants, antihistamines, oral contraceptives, beta-blockers (propranolol, atenolol, etc.), eye drops used to treat other eye diseases, drugs for the treatment of peptic ulcer and some other drugs.
Diseases. In some people, dry eyes appear as a symptom of a general disease of the body. For example, dry eyes can develop with rheumatoid arthritis, Sjogren’s syndrome, systemic lupus erythematosus (SLE), etc.
Adverse external conditions causing increased evaporation of tears
low air humidity (due to central heating or air conditioning)
long stay behind the monitor (TV, microscope, etc.) leads to a decrease in the frequency of blinking, often with a wider than the normal opening of the eyes. This causes an increased evaporation of tears, a decrease in the volume of tears secreted by the glands, a decrease in the rate of exchange of tear fluid.
the incomplete covering of the eye for centuries (for example, in the case of thyroid eye disease); sleep with eyes not fully closed.
Damage to the outer surface of the eye, eyelids, etc. as a result of illness, damage to the eye or surgery.
Blepharitis (inflammation of the eyelids)
Unknown reason. In some young people, the tear fluid is less than normal for an unknown reason.
Symptoms of dry eyes
Symptoms of dry eyes include:
Feeling of a foreign body (“sand in the eyes”), eye irritation, “sting”, “burning”. Red eyes may indicate other more serious eye problems.
A small at times appearing blur of the image (dry eyes usually do not lead to permanent deterioration of vision). Deterioration of visual performance by the end of the day.
Photophobia (bright light causes discomfort).
Poor tolerance to wind, smoke, conditioned air, etc.
For those who use contact lenses, their wearing becomes uncomfortable (feeling of “sand in the eyes”, eye irritation, pain, burning, redness of the eyes).
Dryness of the eye may not be felt as “real dryness” at all. As can be seen from the above list, the symptoms may be quite different.
What threatens to dry eyes
Complications with dry eyes are quite rare. Sometimes there is inflammation of the conjunctiva (conjunctivitis) or cornea (keratitis). In severe cases, corneal ulceration occurs (small ulcers are formed). Rarely, ulcers penetrate the cornea through (this condition is called the perforation of the cornea).
In the case of reddening of the eyes or persistent visual impairment (stronger than the temporary blurring of the image), it is necessary to consult an ophthalmologist. A visit to the doctor is also necessary in cases where there is a feeling of pain in the eye, and not just a “feeling of sand” or irritation of the eye.
How to determine dry eyes
The doctor usually diagnoses dry eyes based on symptoms. However, since dry eye may be a symptom of another disease (for example, Sjogren’s syndrome), the doctor may ask the patient about other symptoms and conduct a more detailed eye examination.
To confirm the diagnosis of dry eyes conduct a special test (Schirmer test). To do this, under the lower eyelid of the patient insert a special narrow paper strip and leave it for 5 minutes. According to the degree of wetting of the strip in 5 minutes, it is determined whether there is enough tear fluid to discharge the patient’s eye.
Treatment of dry eyes
Artificial Tears Drugs
Artificial tears come in the form of eye drops or gel. An artificial tear usually relieves negative symptoms well. These drugs are sold without a prescription in pharmacies, but they can also be prescribed by a doctor on prescription. In the beginning, they may have to be used frequently (after an hour, or even more often) to eliminate the symptoms. With the improvement of drugs, artificial tears can be applied less frequently (3-4 times a day). You may have to use them regularly.
dry eye drops Produced different types of artificial tears, differing in composition. It happens that in some people a certain type of droplets causes irritation. In this case, you should switch to other drugs.
Please note that some types of artificial tear drops contain benzalkonium hexachloride as a preservative. If such drops are used for a long time, then this preservative may damage the cornea. Therefore, if artificial tears are used more often 4 times a day for a long time, it is better to use drops that do not contain benzalkonium hexachloride.
Eye ointments (lubricants)
To relieve irritation and lubrication of the eyes apply eye ointment (lubricant), which is applied overnight under the eyelid. Ointments are sold in pharmacies without a prescription or prescription. Eye ointments should not be used during the day, as they can reduce the effectiveness of eye drops and cause blurring of the image. Do not use ointments if you use eye drops to treat other eye diseases (for example, glaucoma). Eye drops will work poorly if eye ointment is already applied to the surface of the eye.
Preparations of the artificial environment and removing eye irritation ointment in most cases quite successfully eliminate the symptoms of dry eye. In cases where they do not help, the ophthalmologist may advise stronger drugs to increase the production of tear fluid. Sometimes a surgical method is used to block the outflow of tear fluid from the eye. Some methods aim to eliminate the cause of dry eyes.
Contact lenses and dry eyes
Dry eyes are one of the common causes of not wearing contact lenses. Especially often dry eyes when wearing contact lenses are felt by the end of the day, when working in adverse conditions (conditioned air, smoke, etc.), with a long stay behind the monitor. If the user of contact lenses is constantly faced with the problem of dry eyes, then you should discuss this problem with the contact doctor. He may recommend switching to a different type of contact lens (with different moisture content or from biocompatible materials) or use a different multifunctional solution to care for contact lenses.
Moisturizing/lubricating drops are also used to eliminate or at least reduce the symptoms of dry eyes.
Note also that contact lenses cannot be worn when using many eye drops. Preservatives contained in these drops can cause symptoms of dry eyes. You can not also wear contact lenses when using eye ointments.