conjunctival xerosis

Introduction

Introduction to conjunctival xerostomia Conjunctival xerosis is a phenomenon of conjunctival dryness that occurs mainly due to lesions of the conjunctival tissue itself, for a variety of reasons. Under normal circumstances, tears secreted by the lacrimal gland and conjunctival goblet cells keep the conjunctiva constantly moist, and once the above-mentioned moisturizing function is destroyed, conjunctival dryness occurs. Conjunctival dryness can be divided into epithelial conjunctival xerosis and substantial conjunctival xerosis. Clinical application of cod liver oil eye drops, combined with antibiotic solution and eye ointment to prevent and treat secondary infection, corneal ulcer and corneal softening. Under normal circumstances, the surface of the conjunctiva cornea is covered with a layer of oil secreted by the meibomian glands. The lower layer is the aqueous layer secreted by the lacrimal gland. The innermost layer is the mucus layer secreted by the goblet cells. These three layers together form a layer of protection and moisturization. The conjunctival tear film, when the conjunctival epithelial cell layer and subconjunctival tissue are destroyed by lesions, such as severe trachoma scar, diphtheria conjunctivitis, conjunctival pemphigus, conjunctival chemical injury or thermal burn, after X-ray irradiation, due to extensive scarring The formation of the lacrimal duct is blocked by the scar, the lacrimal gland and the conjunctival goblet cells are destroyed, so that the tears and mucus can not wet the eyeball. In addition, the eyelids are closed due to various reasons, and the conjunctiva and cornea can be dried for a long time. . basic knowledge The proportion of illness: 3% Susceptible people: no specific population Mode of infection: non-infectious Complications: filamentous keratopathy

Cause

Causes of conjunctival dryness

Malabsorption (35%):

Such as indigestion, gastroenteritis, dysentery, etc. can affect the absorption of vitamin A, and the lack of vitamin A can cause lesions of the intestinal wall epithelium, thus forming a vicious circle, excessive consumption of children in early childhood growth and development, The demand for vitamin A is large, and the consumption of vitamin A increases when suffering from measles, pneumonia, whooping cough and the like.

Vitamin A deficiency (30%):

Adult vitamin A deficiency is occasionally seen in long-term severe gastrointestinal digestive diseases, vitamin A malabsorption, liver and lung diseases: such as cirrhosis, advanced liver cancer, severe liver damage due to severe liver damage, resulting in fat-soluble vitamin A deficiency .

Abnormal secretion (20%):

Under normal circumstances, the surface of the conjunctiva cornea is covered with a layer of oil secreted by the meibomian glands. The lower layer is the aqueous layer secreted by the lacrimal gland. The innermost layer is the mucus layer secreted by the goblet cells. These three layers together form a layer of protection and moisturization. The conjunctival tear film, when the conjunctival epithelial cell layer and subconjunctival tissue are destroyed by lesions, such as severe trachoma scar, diphtheria conjunctivitis, conjunctival pemphigus, conjunctival chemical injury or thermal burn, after X-ray irradiation, due to extensive scarring The formation of the lacrimal duct is blocked by the scar, the lacrimal gland and the conjunctival goblet cells are destroyed, so that the tears and mucus can not wet the eyeball. In addition, the eyelids are closed due to various reasons, and the conjunctiva and cornea can be dried for a long time. .

Prevention

Conjunctival dryness prevention

Its incidence accounts for 2.7% of the population, and about 30 million people in China suffer from keratoconjunctivitis of varying degrees.

Because many patients with dry eye do not know how to take eye care in normal times, the development of lesions is often accelerated, the degree of lesions is aggravated, and because the ophthalmologists in primary hospitals lack sufficient understanding of this disease, such patients are often misdiagnosed and not timely. The correct diagnosis and treatment is even given the wrong treatment.

Measures to prevent dry eye disease:

1, develop a habit of blinking, dry eye disease is a stress-type illness, the problem is that the eyes are staring in one direction for a long time, so the best way to avoid eye fatigue is to rest properly, avoid continuous operation.

(1) It is very important to have a pair of suitable glasses. For those over 40 years old, it is best to use a bifocal lens, or wear glasses with a lower degree when typing.

(2) The posture and distance of the work are also very important. Try to keep the distance at 60cm and adjust the most appropriate posture so that the line of sight can be kept down about 30°. This angle can relax the neck muscles, and Minimize the area of the surface of the eye that is exposed to the air.

2, long-term computer operators, should eat more fresh vegetables and fruits, while increasing the intake of vitamin A, B 1, C, E, in order to prevent corneal dryness, dry eyes, decreased vision, and even night blindness. Computer operators should eat more foods rich in vitamin A. Vitamin C can effectively inhibit cell oxidation. The main functions of vitamin E are: lowering cholesterol, removing body waste, preventing cataracts, and rich in vitamin E and vitamins in walnuts and peanuts. B1 can nourish nerves, green leafy vegetables contain a lot of vitamin B1, and green tea can be properly consumed every day. Because the lipopolysaccharide in tea can improve the body's hematopoietic function, tea also has the function of preventing radiation damage.

3. In order to avoid the reflective or unclear screen, the computer should not be placed on the opposite side or the back of the window. The ambient lighting should be soft. If there is a window behind the operator, the curtain should be pulled up to avoid the bright light directly shining on the screen and reflecting the bright image. Eye fatigue, usually, the average person blinks less than 5 times a minute to dry the eyes. When a person works in front of the computer, the number of blinks is only one-third of the usual, thus reducing the lubricant and enzyme in the eye. Secretion, should be more blinking, at least once every hour to rest your eyes.

4, in order to reduce the dryness of the eye, you can use corneal nutrient solution in the eye, such as: Beifu Shu eye drops, Xiao Laiwei eye drops and some artificial tears, and other eye exercises can also relax eyes, reduce vision The role of fatigue.

Complication

Conjunctival xerosis complications Complications filamentous keratopathy

There is mucus or more debris in the tear film, and there are filaments on the cornea.

Symptom

Symptoms of conjunctival xerosis Common symptoms Dry eyes, soreness, fatigue, conjunctiva, foreign body, dry eye, closed eyes, incomplete keratoconjunctivitis, conjunctiva, dry plaque, valgus keratitis

The conjunctiva is dry and loses its luster and elasticity, and the transparency is reduced. When the patient blinks the conjunctiva for a few seconds, the drying is more obvious. If the film is examined on the conjunctiva, the keratinized particles of the epithelial cells and a large amount of dried bacilli can be found. Subsequently, the conjunctival activity and elasticity were poor. When the eyeball was rotated, the conjunctiva of the cleft palate appeared parallel to the limbus. On the bilateral sides of the limbus of the cleft part, a silvery white foamy triangular spot appeared, and the basement to the cornea. The edge is dry and not wet. It is called a dry spot (Bitot spot). At the beginning, only a small amount of tiny foam is emitted on the surface of the conjunctiva. It is broken into a grayish white shape, which changes from an ellipse to a triangle. Conjunctival hyperpigmentation is also the disease. Early manifestations, first seen in the lower jaw, in the lower jaw, in the lower conjunctiva and half-moon folds, and finally in the upper palate can also appear light brown pigmentation, after the cure, the conjunctival dry first disappeared, but the pigmentation disappeared Slower.

The early conjunctival goblet cells disappeared, the epithelial cells were hyaline degeneration, and sometimes pigmentation was observed. Later, the epithelial cells became flattened and thickened, the nucleus disappeared, and the keratinization changed. The dry plaque contained meibomian gland secretions, epithelial debris, and fat. Etc., or have dry bacilli.

The surface of the early conjunctiva is dull and dull, the tissue becomes thicker and tends to be keratinized, so that the appearance is like a dry skin. Although it can be moistened by tears, the wrinkled, dry, keratinized conjunctival epithelium causes an unbearable dry feeling and fear. Light and other pain, while the conjunctiva changes, the cornea is also involved, the epithelial layer begins to dry, turbid, resulting in decreased or even lost vision.

For valgus valgus, eyelid defect, and eyelid closure, it can cause localized conjunctival dryness and exposed keratitis, sputum at the exposed site, conjunctival hyperemia, dryness, keratinization and thickening.

Examine

Conjunctival dryness examination

1. Tear secretion test: Normal is 10-15mm, <10mm is low secretion, <5m is dry eye, no ocular surface anesthesia is used, the test is the secretion function of the main lacrimal gland; after anesthesia is detected by the lacrimal gland Secretory function (basal secretion), the observation time is the same as 5min.

2, tear film rupture time <10s for tear film instability.

3, tear fern experiment: mucin deficiency, such as eye pemphigus, Stevens-Johnson syndrome, "fern" reduced or even disappeared.

4, biopsy and imprinted cytology: dry eye syndrome patients with conjunctival goblet cell density decreased, cell nucleoplasmic ratio increased, epithelial squamous metaplasia, corneal epithelial conjunctival, by calculating the density of goblet cells in the conjunctiva, can be indirectly assessed Severity of the disease.

5, fluorescein staining: positive for corneal epithelial defects, you can also observe the height of the tear river.

6, tiger red staining: sensitivity is higher than fluorescein staining, horn, conjunctival inactivation cells stained positive cells.

7, tear lysozyme content: content <1 200g / ml, or lytic zone <21.5mm2, it suggests dry eye syndrome.

8, tear osmotic pressure: dry eye and contact lens wearer, tear osmotic pressure increased by 25mOsm / L compared with normal people, such as greater than 312mOms / L, can diagnose dry eye syndrome, this is specific, has a higher early Diagnostic value.

9. Lactoferrin: If it is less than 1.04bg/ml before the age of 69, if it is lower than 0.85mg/ml after 70 years old, dry eye syndrome can be diagnosed.

10, tear clearance rate check: The purpose is to understand the delay of tear clearance, using fluorescence spectrophotometry.

11. Dry eye meter or tear film interference imager: Understand the tear film lipid layer, dry eye, especially in patients with LTD, the tear film lipid layer is abnormal, compared with the standard image, the dry eye severity can be inferred.

12. Corneal topographic examination: To understand the regularity of the corneal surface, the regular parameters of the corneal surface (surface regularity index and surface asymmetry index) of dry eye patients are higher than those of normal people, and the degree of increase is positively correlated with the severity of dry eye.

13, serological examination: understanding of autoantibodies, SS patients see ANA antibodies, rheumatoid factor and other positive, this is conducive to the diagnosis of dry eye caused by immune diseases.

Diagnosis

Diagnosis and diagnosis of conjunctival dryness

The disease can be seen in the surface punctate keratitis and should be identified.

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