Herpetic keratitis: a description, forms, causes, symptoms and treatment
Inflammatory processes in the cornea can be caused by endogenous and exogenous keratitis. In the first case, internal processes lead to their development. Exogenous keratitis provokes external factors. Identify the reasons that led to the development of the disease, and establish an accurate diagnosis should an ophthalmologist.
Description of the problem
Herpetic keratitis is an infectious disease that affects the cornea of the eye. It can be caused by one of 5 types of herpes viruses. The most common is HSV-1.This is a herpes simplex virus type 1, antibodies to it are found in 90% of the population. It affects, as a rule, the upper part of the body. Most of all, the face suffers.
But the cause of herpes keratitis may also be:
- herpes simplex virus type 2;
- herpes zoster( it causes shingles and chickenpox);
- Epstein-Barr virus;
But most of the time the eye affects HSV-1.
Herpetic keratitis is characterized by the fact that the membrane of the eye becomes cloudy. As a result of such a lesion, a person's eyesight deteriorates considerably, he may even go blind.
The virus can affect both adults and children who have not yet turned 5 and 5 years old. The primary symptoms of his appearance are:
- blepharospasm( a condition in which the eyelids involuntarily spasmodically closed);
But this is not yet a complete list of signs by which you can determine herpetic keratitis. Symptoms of the disease can be as follows:
- redness of the eye;
- feeling of getting foreign body;
- burning sensation;
- pain in the eye.
Primary infection may cause vesicles on the eyelid and conjunctiva. It heals without scarring. Cornea with primary lesion remains in most cases untouched.
Reactivation of the virus causes periodic herpetic keratitis. The case history, forms of the disease are important for further diagnosis and treatment tactics. In latent form, the virus remains in the sensory ganglion. When reactivated, it is transported to the nerve endings, after which the eyeball becomes infected.
Forms of the disease
Depending on the clinical picture, several types of lesions are distinguished. Classical herpetic disease is manifested by branching ulcers on the cornea. This is the so-called epithelial herpetic keratitis. It affects only the outer layer of the cornea, which consists of flat cells of the epithelium.
Specialists distinguish a tree-like and geographic type of disease. The diagnosis is determined depending on how widespread the inflammatory reaction is. It is also important how strongly corneal tissue is destroyed.
Doctors diagnose "dendritic herpetic keratitis" in cases where ulcers on the cornea are similar to branches of trees. The situation is slightly worse if the doctor speaks of a geographical defeat. This means that the cornea is damaged more seriously. The areas of the destroyed epithelium are significant, and their outlines resemble a schematic representation of the continents on the maps.
Stromal keratitis is also called discoid. This disease affects not the outer layer of the cornea, but its internal surface - the stroma. The most dangerous species is stromal necrotic keratitis. In this type of disease, inflammation develops rapidly. It can cause destruction of the corneal tissue. Ultimately, this can lead to blindness.
The first two forms of herpetic keratitis( tree and geographic) with adequate treatment result in complete recovery.
To prevent the development of complications, it is necessary to contact the ophthalmologist when the first signs of the disease appear. He can diagnose and find the most suitable treatment.
The doctor evaluates the patient's condition, looks at the manifestations of the disease. He also measures the intraocular pressure. To determine the extent of damage, it is necessary to drip into the eyes fluorescein. This is a special reagent, which is visible under ultraviolet light. With its help, you can assess how herpetic keratitis damaged the surface of the cornea.
Diagnostics also allows you to identify which layers the virus has struck. Depending on this, the tactics of treatment will be determined.
Laboratory studies of
In most cases, the clinical picture of keratitis is pronounced. But there are situations where even with the help of special tests it is not possible to accurately diagnose. Then a laboratory test may be required. It is also necessary when the virus is infected with herpes simplex neonates.
For its conduct can take smears from the cornea. But such research is low-sensitivity. DNA testing will be more informative. However, this is quite an expensive examination, so it is used very rarely. Serological tests are informative at primary lesion: they show the growth of antibodies. But when the virus is reactivated, they become useless.
Causes of the disease
Herpetic keratitis of the eye is an infectious disease. In the primary lesion of the herpes simplex virus, in most cases, no symptoms appear. Occasionally, characteristic bubbles may develop around the lips.
Once in the body, the virus remains forever in the cells of the trigeminal nerve. It is in a latent state. But from time to time, reactivation is possible. In this case, the pathogen begins to multiply actively. Viruses can travel to the tissues of the face and eyes.
Herpetic keratitis usually appears after the reactivation of the virus. Once on the cornea of the eye, the virus continues to multiply.
But the destruction of tissues begins because of the reaction of the immune system. After all, it is responsible for the development of an inflammatory reaction. Immune cells can recognize viruses and destroy tissues that are infected. Sometimes the harm from the reaction of immunity is much stronger than from the action of the virus itself.
What leads to the reactivation of the virus?
Almost 90% of people are carriers of herpes simplex virus. But not all have herpetic keratitis. Researchers believe that the infection can develop under the influence of certain factors and conditions that affect the body.
For a long time physicians believed that the virus is activated against the background of stress. But a survey of a group of people disproved this assumption. Therefore, doctors can not say exactly what causes this type of keratitis.
But it is established that those people who suffered various operations before the eyes are more susceptible to this disease. This can be laser correction of vision, removal of cataracts, treatment of glaucoma, transplantation of the cornea.
Tactics of treatment
The necessary therapy can be prescribed only after examining the ophthalmologist. He must confirm the diagnosis of "herpetic keratitis of the eye".Treatment is also selected by a specialist.
If herpes affected only the eyelids, then it will be enough to only use tablets "Acyclovir" or "Valaciclovir".They need to be drunk for 5 days. To treat epithelial keratitis, you will need to purchase an eye gel that contains 0.15% ganciclovir or drops with 1% trifluridine. Also, an ointment "Acyclovir" can be prescribed. It must be laid for the lower eyelid at least 5 times a day.
Treatment continues until complete healing. In some cases it is enough to take only tablets "Acyclovir".If such treatment is ineffective, then drops with interferon are used.
Stromal keratitis is harder to treat. In the first two days, tablets "Acyclovir"( 2 g per day) or "Valaciclovir"( 1 g per day) are prescribed. In such a dosage, they should be drunk for up to 2 weeks. If in the first two days of the course the disease does not progress, then in the future it is recommended to use drops with dexamethasone 0.1%.Initially, they drip up to 8 times a day, but gradually the frequency of use is reduced every 3-6 days for 1 drop. Such treatment should last several months.