Keratitis

Introduction to keratitis Keratitis refers to inflammation caused by corneal trauma, bacteria and viruses invading the cornea, ulcerative keratitis (also known as corneal ulcer), and non-ulcer keratitis (ie deep keratitis). Ulcerative keratitis is mostly caused by external factors, that is, inflammation of the infectious virulence factors caused by external invasion of the corneal epithelial cell layer. Non-ulcer keratitis refers to diffuse inflammation within the corneal parenchyma. It is mostly an expression of an antigen-antibody reaction, such as congenital syphilitic keratitis, but it can also be seen in tuberculosis, viruses and certain mold infections. Trauma and infection are the most common causes of keratitis. When the corneal epithelial layer is damaged by mechanical, physical, and chemical factors, bacteria, viruses, and fungi enter the cell and cause infection. Invasive pathogenic microorganisms can be derived from external injuries or from various pathogens hidden in the eyelids or conjunctival sacs, especially chronic dacryocystitis, which is a risk factor for corneal infection. The basic principle of treating corneal ulcers is to take all effective measures to quickly control the infection, strive for early cure, and reduce the sequelae of keratitis to a minimum. Since most ulcerative keratitis is caused by external causes, it is extremely important to eliminate pathogenic microorganisms and eliminate pathogenic microorganisms. basic knowledge The proportion of sickness: 0.01% Susceptible people: no special people Mode of transmission: partial contact spread Complications: iridocyclitis cataracts corneal staphyloma

Cause of keratitis

Systemic disease (15%):

Systemic disease is an intrinsic factor. For example, allergic keratitis caused by tuberculosis, rheumatism, syphilis, and the like. Systemic malnutrition, especially corneal softening caused by vitamin A deficiency in infants and young children, and paralytic keratitis caused by trigeminal nerve palsy. In addition, there are autoimmune diseases such as mooring corneal ulcers whose causes are unclear.

Trauma and infection (35%):

Causes of keratitis: Trauma and infection are the most common causes of keratitis. When the corneal epithelial layer is damaged by mechanical, physical, and chemical factors, bacteria, viruses, and fungi enter the cell and cause infection. Invasive pathogenic microorganisms can be derived from external injuries or from various pathogens hidden in the eyelids or conjunctival sacs, especially chronic dacryocystitis, which is a risk factor for corneal infection.

Effects of corneal adjacent tissue disease (15%):

Causes of keratitis: effects of corneal adjacent tissue disease. For example, acute conjunctivitis can cause superficial punctate keratitis, scleritis can lead to sclerosing keratitis, and uveitis can also cause keratitis. Exposure keratitis can occur when the eyelid defect is combined with cleft palate closure.

pathology

Clinical common keratitis formation

Claudication keratitis: mainly caused by bacteria with strong virulence. Pneumococcal, hemolytic or Streptococcus mutans, Neisseria gonorrhoeae, Bacillus subtilis, Staphylococcus aureus, etc. can cause disease. Before the onset of the disease, there is often a history of corneal surface trauma, or foreign matter such as dust. Systemic malnutrition and weakness are also prone to disease; patients with chronic dacryocystitis are susceptible to this disease.

Pseudomonas aeruginosa keratitis: This disease is caused by Pseudomonas aeruginosa directly invading the cornea. Pseudomonas aeruginosa is very toxic, but its invasiveness is very weak. It must pass through the damaged epithelium to invade the corneal tissue and cause infection. Therefore, various corneal trauma, keratitis, corneal softening, etc. can be the cause of infection.

Keratitis prevention

1. Cultivate good personal hygiene habits, keep clean at all times, wash your hands with soap, and keep dry.

2. Avoid rubbing your eyes with your hands:

Rubbing your eyes with your hands is a lot of harm, especially for children. The child is moving, the little hand is always dirty, rubbing his eyes with dirty hands, will bring some germs into his eyes, causing inflammation of the eyes, and sometimes the sand on his hands will be into his eyes.

When playing with a child with eye disease, rubbing your eyes with your hands will infect the same eye disease. If one eye is red and itchy, rubbing your eyes with your hand will pass the eye disease to the other eye. If the eyes are filled with foreign matter such as sand, rubbing your eyes with your hands is like rubbing the eyes back and forth with a grinding wheel, causing damage to the epithelium of the black eyeballs. In severe cases, it may also infect the disease. If the eyes are itchy, you can drop the eye drops, eyes. When entering the sand, you should first rinse it with anti-inflammatory eye drops, then go to the hospital for treatment. Never rub your eyes with your hands.

3. Try to avoid public places where there are many people during the popular period.

4. Try to avoid swimming in the public swimming pool during the popular period.

5. Avoid shaking hands with patients and contact with towels, soap, bedding, door handles, faucets, etc. used by patients.

6. After the patient has healed, the used quilt and towel should be washed and completely exposed to the sun.

7, patients should maintain physical and mental health, not to sleep late, do not drink alcohol, do not smoke, etc., in order to effectively prevent or reduce symptoms.

8, should pay attention to the usual diet nutrition and health:

Protecting your eyes is not just about dropping your eye drops. Its more important to start with your eating habits. Because the eyes need the moisture of tears, and the tears contain a variety of nutrients, the most important of which is vitamin B2; the process of visual need vitamin A participation; the transmission of optic nerve requires the help of vitamin B family; prevention of eye aging needs Healthy blood vessels, vitamin C and vitamin E are very helpful. Vitamin A is a vitamin that Chinese people are prone to lack. In the absence of vitamin A, the eyes often feel dry, cyanotic, and easily fatigued. In severe cases, the white surface of the eye is dry, wrinkled, and even causes corneal ulcers. Before these symptoms occur, the dark vision of the person has been reduced, and the dark adaptation ability is poor, that is, it is difficult to adapt from the light to the dark. Vitamin A should be eaten more with liver, milk, egg yolk, green leafy vegetables, carrots, sweet potatoes, etc. Lack of vitamin B2 can easily cause the population's horns, lips and tongue to become inflamed, and it can also make the eyes dense with blood, afraid of light, and easy to shed tears.

9, to avoid excessive use of the eyes:

Excessive use of the eyes for a long time is a major cause of eye fatigue. The general symptom of eye fatigue is that the object is blurred for a long time, and some even can not write or read, dry eyes, dizziness, nausea and vomiting in severe cases. In addition, visual fatigue also causes myopia or premature eye in adults, and various eye diseases are accompanied by excessive use of the eye. Protect your eyes, prevent eye damage, slow eye fatigue, ensure proper light, maintain proper posture, ensure rest and eye exercises.

Keratitis complications Complications, iridocyclitis, cataract, corneal staphyloma

Anterior chamber empyema

In severe cases, there are many cases of iridocyclitis. Because the white blood cells exuded by the iris ciliary body make the anterior chamber water turbid, sinking in the lower part of the anterior chamber angle, the name is anterior chamber empyema. It is a horizontal plane because it is a liquid. When the head is tilted, the liquid changes direction gradually toward the lower side.

2. Post-elastic film bulging

Because corneal ulcers can progress deeper, when the cornea is to be perforated, a thin layer of transparent tissue can appear on the ulcer base, shaped like a "black" vesicle that protrudes forward and is surrounded by a gray ulcer. This protrusion is formed by the rear elastic film, so the name is elastic and the film is swollen.

3. Corneal perforation

When the cornea is perforated, the patient feels violent pain and tears (aqueous humor) flow out, but the original pain symptoms disappear; after the perforation, the aqueous humor overflows, first the anterior chamber becomes shallow or even disappears, followed by the iris and the lens forward. Displacement and contact with the posterior wall of the cornea, the eyeball changes. Although the pupil used to use atropine in the past, it will shrink.

4. Front cataract

If the perforation is small, located in the center of the cornea, the iris can begin to heal without prolapse. When the aqueous humor has flowed out and the perforation has not been blocked by a sufficiently thick fibrous exudate, the lens continues to contact the posterior wall of the cornea. When the anterior chamber is formed and the anterior capsule of the lens is out of contact with the posterior wall of the cornea, the central portion of the lens The anterior capsule surface and the subcapsular tissue have undergone permanent turbidity, forming a anterior cataract.

5. Iris prolapse

If the perforation occurs at a distance from the center of the cornea, the iris must block the hole. In the larger perforation, the iris is pushed to the front by the liquid in the back room, and enters the hole to escape. The initial part of the prolapse is usually brownish black, and soon the surface of the fiber is formed by fibrous exudates, similar to the gray-yellow cap, covering the prolapsed part, forming part of the iris to escape. At this time, the exudate is fused with the edge of the ulcer to isolate the anterior chamber from the outside. At this time, the anterior chamber quickly recovered and the scar began to form. The iris is gradually healed and gradually calmed down. The iris is permanently fixed within the perforation.

6. Corneal staphyloma

7. Corneal fistula

Symptoms of corneal inflammation Common symptoms Visually impaired eyes have foreign body aggression and tears in the eyelids are obvious... Eye burns eye pain, tears, ciliary congestion

Patients with keratitis have symptoms of inflammation, such as pain, shame, tearing, and eyelids. This is caused by inflammation of the trigeminal nerve endings in the cornea, causing reflex orbital muscle contraction and tear secretion. The cornea is an avascular tissue, but the adjacent area is rich in blood vessels (the blood vessels of the limbus and iris ciliary body). When the inflammation involves adjacent tissues, there is congestion and inflammatory exudation. Therefore, patients with keratitis not only have ciliary congestion, but also iris congestion. The latter manifested as iris discoloration and pupil dilation.

Keratitis examination

1. Check systemic and local pathogenic factors. Suppurative inflammation should be smear examination, bacterial, fungal culture and drug susceptibility test; tree branch and superficial punctate keratitis for immunological examination.

2, pay attention to the lesion location, size, shape, depth, surface depression or bulge, to distinguish between ulcerative and non-ulcerative, with or without new blood vessels, pay attention to the posterior corneal wall. Fluorescein staining was performed and regular plots were recorded to document evolution. Do not oppress the eye to avoid perforation during examination and treatment.

3, check for iritis, pay attention to the shape and size of the pupil, the degree of turbidity of the aqueous humor, with or without anterior chamber empyema.

4. Check the corneal sensation.

Diagnosis and differentiation of keratitis

Keratitis and conjunctivitis are among the most common diseases on the ocular surface. There are some similarities in their symptoms, which can be manifested as eye discomfort, tearing, increased secretions in the eye, and congestion, which can easily be confused.

Conjunctivitis is a common disease in ophthalmology, but its incidence has not yet been determined. Since most of the conjunctiva is in direct contact with the outside world, it is susceptible to infections (such as bacteria, viruses, and chlamydia) and non-infectious factors (trauma, chemical and physical factors) in the surrounding environment, as well as blood vessels and lymph nodes of the conjunctiva. The organization is rich, and its own and external antigens are easy to sensitize. Conjunctivitis is a general term for the inflammatory reaction of conjunctival tissue in the external and internal factors. Although conjunctivitis itself is generally not severely affected by vision, it can cause vision damage when its inflammation affects the cornea or causes complications. Therefore, we must pay attention to the differential diagnosis of keratitis and conjunctivitis.

The material in this site is intended to be of general informational use and is not intended to constitute medical advice, probable diagnosis, or recommended treatments.