corneal ulcer
Introduction
Introduction to corneal ulcer The cornea is the transparent film on the front of the eyeball, which is often exposed to the air and has a lot of exposure to germs. Often due to foreign bodies and other trauma, corneal foreign body removal after injury and trachoma and its complications, varus stunned cornea, bacteria, viruses or fungi take the opportunity to cause infection and corneal ulceration. In addition, allergic reactions such as tuberculosis, vitamin A deficiency, facial paralysis and eye scars can cause corneal ulcers. If the corneal ulcer is treated in time, the ulcer can be repaired and healed gradually, but often becomes scarred and turbid. basic knowledge The proportion of illness: 0.003% Susceptible people: no special people Mode of infection: non-infectious Complications: cataracts, purulent endophthalmitis
Cause
Cause of corneal ulcer
Trauma and infection (35%):
Causes and complexities of corneal inflammation, trauma and infection, are the most common causes of keratitis; tuberculosis, rheumatism, syphilis, malnutrition and other systemic diseases, is an intrinsic factor; the effects of corneal neighboring tissue diseases such as Acute conjunctivitis, scleritis, uveitis, etc.
Prevention
Corneal ulcer prevention
The vast majority of patients are farmers, although they can occur throughout the year, but mainly concentrated in the agricultural summer harvest and autumn harvest season.
1. Develop good hygiene habits, wash your hands frequently, and often cut your nails.
2, do not wear contact lenses for a long time; be careful when replacing contact lenses.
3, the same as the prevention of acute conjunctivitis, mainly to cut off the source of infection and attention to eye and hand hygiene.
4. It is forbidden for patients to bathe and swim in public places.
5, the treatment is mainly based on topical medication, drug oral administration and acupuncture also have a certain effect.
6, eat more foods and fruits with cold and heat and diarrhea, such as white, winter melon, bitter gourd, fresh sorghum, sugar cane, banana, watermelon and so on.
Complication
Corneal ulcer complications Complications cataract purulent endophthalmitis
If the condition is not effectively controlled in time, it can lead to perforation of the cornea, which can further cause endophthalmitis and even total ocular inflammation.
Corneal disease is one of the most harmful to visual function in ocular surface diseases. If it is increasingly serious, it can lead to decreased vision and even blindness, that is, corneal blindness. The cornea is blinded to the second place in blindness and low vision, second only to cataracts.
Symptom
Symptoms of corneal ulcers Common symptoms Teardrops, conjunctiva, congestive corneal ulcer, visual impairment, corneal opacity on the cornea
symptom
The patient is afraid of light, tears, pain, and severe irritations such as eyelids. When the corneal epithelium is exfoliated, it can cause severe eye pain. According to the degree and location of corneal lesions, different degrees of visual impairment may be associated. In addition to purulent corneal infection, there is generally no secretion or secretion. The signs of keratopathy can be bulbar conjunctival edema, ciliary congestion, corneal opacity, corneal neovascularization, and the like.
At the beginning of the disease, the eyes have obvious irritation symptoms, fear of light, tearing, eye pain, grayish white spots or flaky infiltration on the cornea; in severe cases, the above symptoms are more obvious, the eyes are not open, the eye pain is unbearable, and the vision is reduced. The bulbar conjunctiva is purplish red, and the more severe it is near the cornea, the grayish white necrotic tissue can be seen on the surface of the cornea, forming an ulcer. If the bacteria is highly toxic, combined with chronic dacryocystitis or reduced systemic resistance, the ulcer spreads around or deep, forming anterior chamber empyema, and even causing corneal perforation, which causes serious damage to vision. Pseudomonas aeruginosa corneal ulcer, often caused by perforation of the cornea within 1-2 days, the consequences are very serious. The fungal corneal ulcer, the initial symptoms are mild, the ulcer surface is irregular, grayish white, and the anterior chamber often has empyema.
In addition to paralytic keratitis, most 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.
The exudates are from the same source. Edema can occur in the conjunctiva of the severe patient or even in the eyelids. Corneal infiltration occurs due to the movement of leukocytes to the corneal lesion due to hyperemia of the limbus. When the cornea is inflamed to the degenerative phase, the clinical irritation symptoms are greatly alleviated.
Corneal inflammation necessarily affects vision more or less, especially if inflammation invades the pupil area. The scar formed by the healing of the ulcer not only hinders the light from entering the eye, but also changes the curvature of the cornea surface and the refractive power of the refractive lens, so that the object cannot be focused on the retina to form a clear image, and thus the vision is lowered. The degree of vision involvement depends entirely on the location of the scar. If it is in the middle of the cornea, even if the scar is small, it affects vision.
Sign
1 often accompanied by white, yellow-white or gray-white ulcers in front of the empyema, the degree of development is compared with the course of the disease, relatively chronic.
2 eye irritation symptoms and ulcer size comparison, relatively minor.
Examine
Corneal ulcer examination
Take the ulcer surface necrotic tissue for smear examination. If you can find fungal hyphae, or take necrotic tissue for culture, and fungal growth, it is the most reliable diagnosis. The specimen method is to first drop the surface anesthetic, and then use a small pointed blade to scrape a small piece of necrotic tissue with a diameter of 0.5 mm in the infiltrated dense area as a specimen. Generally, potassium oxychloride smear is first checked. If there is still a specimen available, fungal culture can be performed at the same time. Sometimes, the rabbit is used to damage the cornea in the pupil area. Do not take specimens deep in the ulcer to prevent ulceration.
When scraping specimens, it is sometimes possible to make a preliminary identification between fungal and bacterial. Generally speaking, the necrotic tissue of the fungal ulcer surface is "tidal scale" or "toothpaste", the texture is loose and lacks viscosity; and the necrotic tissue of the bacterial ulcer surface is "gelatinized" and rich in viscosity.
Fungal smear
Take a small piece of ulcerated necrotic tissue on a slide, drop a small drop of 5% potassium hydroxide solution onto it, cover with a cover slip, and gently press gently. The fungal hyphae can be detected by high-power microscopy. Many are often full of vision, but a small amount of hyphae needs to be carefully examined to find out. Smear positive, generally can confirm the diagnosis. Specimens need to be inspected at the time and cannot be saved.
Fungal culture
Take a small piece of necrotic tissue and place it on the slope of solid potato or Sabouraud medium. If it can be inoculated on several media at the same time, it will help to increase the positive rate of culture. Place in a 37 degree Celsius incubator and observe daily. Fungal organisms are possible from the next day after inoculation. If there is no growth after one week, it is positive. The culture method can observe the morphology and color of the fungal colonies, and examine the hyphae, spores, etc. under the microscope to identify the strains, preserve the strains, and test the drug sensitivity. The positive rate of culture is generally low.
Diagnosis
Diagnosis and differentiation of corneal ulcer
Bacterial corneal ulcer
More common, is a severe suppurative corneal ulcer. Common claudication corneal ulcers and Pseudomonas aeruginosa corneal ulcers. The former is often accompanied by anterior chamber empyema, also known as anterior chamber pyogenic corneal ulcer. More common in elderly, frail, malnourished, chronic dacryocystitis patients. Often caused by corneal infection after Streptococcus pneumoniae, Mora-Axenfeld, Bacillus, staphylococcal infection. Its clinical features are acute onset, the lesion begins in the center of the cornea, yellow-white infiltration, ulcer formation and progression to the surrounding and deep, often secondary to iridocyclitis, cellulose-like exudation in the anterior chamber, and Form anterior chamber empyema. The empyema is sterile before the corneal perforation. Finally, corneal perforations can be formed. Perforation in most cases is a contributing factor to recovery. However, in severe cases, perforation can cause intraocular infections, resulting in endophthalmitis or total ocular inflammation. If you have dacryocystitis, you should do the removal surgery as soon as possible. Local and systemic treatment with sulfa or cyan and streptomycin. Pseudomonas aeruginosa corneal ulcer is a severe suppurative keratitis. In the case of corneal trauma or removal of corneal foreign bodies, Pseudomonas aeruginosa is infected by adhering to foreign matter or contaminated eye drops. With the promotion of contact lenses, lenses or lens disinfectants are more likely to be infected by pathogens. It is characterized by short incubation period, rapid onset, severe pain and sharp decline in vision, accompanied by a large number of yellow-green sticky secretions. Corneal lesions are gray-yellow infiltration, slightly bulging, edema around them, and soon form a round, annular corneal ulcer, accompanied by anterior chamber empyema, 2 to 3 days can be extended to the whole cornea and perforation. Eventually, endophthalmitis or corneal staphyloma (ie partial or full corneal swelling) is formed and blindness is caused. If you suspect this disease, you should immediately use polymyxin or gentamicin, and every half hour, eye drops and systemic medication until the condition is stable. In addition, carbenicillin and streptomycin have certain effects. Bedside isolation should be done at the same time as treatment.
Viral corneal ulcer
Common causes are caused by herpes simplex infection. There is often a history of fever such as upper respiratory tract infection before onset. Due to the widespread use of corticosteroids, viral infections are on the rise. At the early stage of the onset, the punctate vesicles of the corneal epithelium appear in a linear arrangement. Later, the vesicles rupture and gradually connect into a dendritic shape, and the nodular vesicles at the end are dendritic keratitis. Fluorescein staining showed that the center was green dendritic, with a pale green band next to it, and the cornea felt weakened or disappeared in the lesion area. After treatment, it can heal and leave cloud, and the disease is easy to relapse or prolonged to form a map-like ulcer (Map Crokeritis), often associated with iridocyclitis, but not with anterior chamber empyema, if there is anterior chamber empyema, it may indicate secondary infection. After the ulcer is healed, the spotted or white spots with new blood vessels can be left behind.
Fungal corneal ulcer
The fungus directly invades the cornea, which is more common in the busy season. Common pathogens are Fusarium, Aspergillus, Candida albicans and the like. The onset is slow and the symptoms are lighter than the clinical manifestations. The lesion is characterized by ulceration grayish white, dry surface, slight uplift, and pseudopodia or small five-star foci can be formed around it, often accompanied by anterior chamber empyema. The course of the disease is slow and eventually pierced. The diagnosis of this disease depends on the corneal scraping to find fungal hyphae. Antifungal agents currently use doxyerythromycin or amphotericin. Disable hormones or antibiotics.
