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. The ophthalmologist should identify the causes that led to the development of the disease and establish an accurate diagnosis.
Description of the problem
Herpetic keratitis is an infectious disease that affects the cornea of the eye. It can be caused by one of the 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 body. The face suffers the most.
But the cause of the appearance of herpes keratitis can also be:
- herpes simplex virus type 2;
- herpes zoster (it causes shingles and chickenpox);
- Epstein-Barr virus;
- cytomegalovirus.
But most often it is HSV-1 that affects the eyes.
Herpetic keratitis is characterized by the fact that the membrane of the eye becomes cloudy. As a result of such a defeat, a person’s vision deteriorates significantly, he may even become blind.
Symptoms of the disease
The virus can affect both adults and children who are not yet 5 years old. The primary symptoms of its appearance are:
- lacrimation;
- blepharospasm (a condition in which the eyelids involuntarily close spasmodically);
- photophobia.
But this is not a complete list of signs by which herpetic keratitis can be determined. Symptoms of the disease may be:
- redness of the lining of the eyes;
- a feeling of falling into a foreign body;
- burning;
- pain in the eye.
With a primary infection, vesicles on the eyelid and conjunctiva may appear. She heals without scarring. The cornea in the primary lesion remains intact in most cases.
Reactivation of the virus causes periodic herpetic keratitis. The history of the disease, the form of the disease are important for further diagnosis and determination of treatment tactics. In latent form, the virus persists in the sensory ganglion. During reactivation, 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. The classic 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
epithelial cells.
Specialists distinguish a tree-like and geographical type of disease. The diagnosis is made depending on how common the inflammatory reaction is. It is also important how much corneal tissue is destroyed.
Doctors diagnose herpetic keratitis keratitis in cases where corneal ulcers look like tree branches. The situation is a little worse if the doctor speaks of a geographical lesion. This means that the cornea is damaged more seriously. The areas of destroyed epithelium are significant, and their outlines resemble a schematic representation of continents on maps.
Stromal keratitis is also called discoid. In this disease, it is not the outer layer of the cornea that is affected, but its inner surface, the stroma. The most dangerous type is stromal necrotic keratitis. With this type of disease, inflammation develops rapidly. It can cause corneal tissue destruction. This can ultimately lead to blindness.
The first two forms of herpetic keratitis (treelike and geographical) with adequate treatment end in complete recovery.
Diagnostics
To prevent the development of complications, it is necessary to contact an ophthalmologist when the first signs of the disease appear. He can diagnose and select the most appropriate treatment.
The doctor evaluates the patient's condition, looks at the manifestations of the disease. It also measures intraocular pressure. To determine the degree of damage, it is necessary to instill fluorescein in the eyes. This is a special reagent that is visible under ultraviolet light. Using it, you can evaluate how herpetic keratitis damaged the surface of the cornea.
Diagnostics also allows you to identify which layers the virus affected. Depending on this, treatment tactics will be determined.
Laboratory research
In most cases, the clinical picture of keratitis is pronounced. But there are situations when even with the help of special tests it is not possible to accurately diagnose. Then laboratory testing may be required. It is also necessary for the defeat of the herpes simplex virus in newborns.
For its conduct, smears from the cornea can be taken. But such a study is low sensitive. DNA testing will be more informative. However, this is a rather expensive examination, therefore it is used extremely rarely. Serological tests are informative for the primary lesion: they show antibody growth. But with the reactivation of the virus, they become useless.
The causes of the disease
Herpetic keratitis of the eye is an infectious disease. With an initial herpes simplex virus infection, in most cases no symptoms appear. Sometimes characteristic vesicles may appear around the lips.
Once in the body, the virus forever remains 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, as a rule, appears after the reactivation of this virus. Once in the cornea, the virus continues to multiply.
But the destruction of tissues begins due to the reaction of the immune system. After all, she is responsible for the development of the inflammatory reaction. Immune cells can recognize viruses and destroy tissues that they are infected with. Sometimes the harm from the immune response is much stronger than from the action of the virus itself.
What causes reactivation of the virus?
Almost 90% of people are carriers of the herpes simplex virus. But not everyone has herpetic keratitis. Researchers believe that infection can develop under the influence of certain factors and conditions that affect the body.
For a long time, doctors believed that the virus is activated against a background of stress. But a survey of a group of people refuted this assumption. Therefore, doctors can not say for sure what is causing this kind of keratitis.
But it was established that those people who underwent various eye operations are more susceptible to this disease. This can be laser vision correction, cataract removal, glaucoma treatment, corneal transplantation.
Treatment tactics
The necessary therapy can be prescribed only after an examination by an ophthalmologist. He must confirm the diagnosis of herpetic keratitis of the eye. Treatment is also selected by a specialist.
If herpes affects only the eyelids, then it will be enough only to use the tablets “Acyclovir” or “Valacyclovir”. They must be drunk for 5 days. For the treatment of epithelial keratitis, you will need to purchase an eye gel that contains 0.15% gancilovir or drops with 1% trifluridine. Ointment "Acyclovir" may also 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 sufficient to take only “Acyclovir” tablets. If such treatment is ineffective, then drops with interferon are used.
Stromal keratitis is more difficult to treat. In the first two days, “Acyclovir” tablets (2 g per day) or “Valaciclovir” tablets (1 g per day) are prescribed. At this dosage, they must be drunk for up to 2 weeks. If the disease does not progress in the first two days of the course, then in the future it is recommended to use drops with 0.1% dexamethasone. Initially, they are dripped up to 8 times a day, but gradually the frequency of use is reduced every 3-6 days by 1 drop. Such treatment should last several months.