Do you still remember that we mentioned in the first article of the "Corneal Classroom" series that once the cornea is damaged and causes keratopathy, the consequences will affect our health infinitely.
So, what is the cause of cornea? What are the clinical manifestations? What is the treatment? Today we will give a detailed explanation.
pathogeny
① The influence of corneal adjacent tissue diseases
The cause of keratopathy may be the influence of the diseases of adjacent corneal tissues on keratopathy.
For example, acute conjunctivitis may cause superficial punctate keratitis; Sclerosis may lead to sclerosing keratitis; Pigment membrane inflammation may also cause keratitis; Exposure keratitis may also occur when eyelid defect is combined with incomplete closure of eyelid fissure.
② Systemic diseases
The cause of keratopathy may also be systemic disease, which is an internal factor.
For example, allergic keratitis caused by tuberculosis, rheumatism, syphilis, etc. Systemic malnutrition, especially keratomalacia caused by vitamin A deficiency in infants and children, and nerve paralysis keratitis caused by trigeminal nerve paralysis.
In addition, there are also autoimmune diseases such as Mooren's corneal ulcer with unclear causes.
③ Trauma and infection
Trauma and infection are the most common causes of keratitis. When the corneal epithelium is damaged by mechanical, physical and chemical factors, bacteria, viruses and fungi take the opportunity to enter and infect.
Invasive pathogenic microorganisms can not only come from external pathogens, but also from various pathogens hidden in the eyelid or conjunctival sac, especially chronic dacryocystitis, which is a risk factor for corneal infection.
clinical manifestation
① Bulbar conjunctival edema
Severe keratitis can cause bulbar conjunctival edema to varying degrees.
② Ciliary hyperemia
When the cornea is inflamed, the anterior ciliary vascular network around the limbus dilates and congests, which is called ciliary congestion. When conjunctival and ciliary congestion occur at the same time, it is called mixed congestion.
Ciliary hyperemia
③ Corneal opacity
It is caused by corneal infiltration, edema or ulcer.
④ Corneal neovascularization
In the process of keratitis or ulceration, when the capillary network around the hyperemic limbus extends new vascular branches into the cornea, it is called corneal neovascularization.
Subepithelial neovascularization, which comes from the superficial vascular network, is dendritic, bright red, and connected with conjunctival vessels. The anterior stromal neovascularization originates from the deep vascular network, while the posterior stromal neovascularization originates from the large ring of the iris artery and the radial branches of the iris vessels extending to the limbus of the cornea. The deep neovascularization is brush shaped and dark red.
In the inflammation stage, corneal neovascularization is easy to see. After the inflammation subsides, the neovascularization that remains on the relatively transparent cornea is difficult to find, except for the lumen, which has no blood.
It should be noted that corneal neovascularization, on the one hand, can make the cornea lose its transparency, on the other hand, cause biochemical changes in the corneal tissue, from not participating in the immune privilege state of the whole tissue to participating in the immune response, which may lead to rejection reaction during corneal transplantation.
Physician examination
It is very important to select the most effective treatment plan and determine the pathogenic factors.
When you go to the hospital for examination, the doctor often asks you: Do you have corneal irritation symptoms and a history of trauma? Have you used corticosteroids locally and systemically? Do you have chronic dacryocystitis, entropion, trichiasis and other eye diseases and related systemic diseases?
After that, the doctor will give you a corresponding eye examination: if the irritation is serious, you may drop the surface anesthetic first and then check. For corneal surface damage, the fluorescein staining rule is easy to find; In addition, the doctor may also use a magnifying glass or slit lamp to check the location and morphology of your corneal lesions; Of course, sometimes you will be examined for corneal perception and tear secretion function.
Treatment of keratopathy
It can be diagnosed and treated according to the medical history, clinical symptoms and laboratory tests.
① Eliminate incentives. As the name implies, it is to eliminate "dangerous people" first, such as entropion, trichiasis, chronic dacryocystitis, conjunctivitis, etc.
② Control infection. For pathogenic microorganisms, doctors will choose appropriate antibiotics to prepare eyedrops or eye ointment of different concentrations for eye drops, which may be used alone or in combination.
③ Mydriasis. If there are scleral irritation symptoms, such as pupil shrinkage, slow response to light and complicated iridocyclitis, mydriasis should be performed. The commonly used mydriatic drugs are 0.5~3% atropine and eye ointment; If necessary, the mydriatic mixture can be injected under the conjunctiva.
④ Hot compress. The application of damp heat compress can dilate blood vessels in the eyes, promote and improve local blood circulation, reduce irritation symptoms, promote the absorption of inflammation, and enhance the repair ability of tissues. The hot compress can be applied 2-3 times a day for 15-20 minutes each time.
⑤ Application of corticosteroids
It is only used when there is still infiltration and edema of corneal stroma after the healing of allergic keratitis or corneal ulcer. For corneal epithelial damage or corneal ulcer caused by various reasons, corticosteroids should be prohibited in principle to avoid aggravating the ulcer or delaying the healing of epithelial damage.
⑥ Bandaging
Cover the affected eyes with sterile gauze to avoid light stimulation, reduce the friction of eyelids on the corneal surface, protect the ulcer wound, reduce pain, promote ulcer healing and prevent secondary infection. Therapeutic soft corneal contact lens can also be worn, but it is prohibited for those with conjunctivitis and purulent secretions. Wear colored glasses when necessary.
⑦ Supportive therapy. A variety of vitamins can be used, such as vitamins C, E and A, D.
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Corneopathy is an important cause of vision loss. It can make the transparent cornea appear grayish white turbidity, which can make vision blurred, impaired, or even blind. Corneal disease can be cured in the early stage if it can be treated timely and accurately. However, if the disease is serious or occurs repeatedly, it will leave thick scars on the cornea. At this time, the only treatment is corneal transplantation. Remove the turbid cornea and replace it with transparent cornea, so that the patient can see again.