Diagnosis of herpes simplex

Diagnosis of herpetic and metaherpetic keratitis in the absence of typical features of the clinical manifestation of the process is very difficult. In these cases, it is necessary to conduct laboratory studies. The most common method of cytological examination of the conjunctiva and the method of fluorescent antibodies, which are used in the diagnosis of viral conjunctivitis. In addition, with herpes in soskob, in addition to specific changes in conjunctival epithelial cells, lymphocytes, plasma cells and monocytes are detected. Despite the obvious practical significance of these laboratory diagnostic methods, they can always satisfy the ophthalmologist. Nowadays, an intradermal test with an anti-herpetic vaccine has been increasingly used for diagnostic purposes.

The vaccine is a preparation obtained from strains of herpes simplex virus II type II, inactivated with formalin. The actual beginning of the vaccine is the specific antigens of the virus. 0.05 ml of herpetic polivaccine is injected into the skin of the inner surface of the forearm, and the same dose of the control antigen from the uninfected material is injected into the skin of the other forearm. If after 24 hours the area of skin hyperemia that occurs in the zone of administration of the herpetic polyantigen will be 5 mm larger than the control side, then the sample should be considered positive.

There is also a focal allergic test with an antiherpetic vaccine, proposed by AA Kasparov and co-authors. (1980). It is shown as a diagnostic etiologic test in patients with frequent relapses of conjunctivitis, keratitis, iridocyclitis and other clinical forms of ophthalmoherpes, with slow processes. The sample is very responsible, in view of the fact that it is estimated by the presence of exacerbation of the inflammatory process in the eye (increased pericorneal injection, pain, the appearance of new infiltrates in the cornea, precipitates, newly formed vessels in the cornea and iris). These signs of a process outbreak require urgent active therapeutic measures in the form of intensification of desensitizing and specific antiviral therapy.

There are a number of contraindications to the formulation of the sample, which include a sharp process in the eye, the presence of infectious and allergic diseases, endocrine system diseases, tuberculosis, and kidney diseases.

A focal sample, which in some cases can also cause a general reaction, should be performed only in a hospital setting. The method of the test consists in introducing into the skin of the forearm 0.05-0.1 ml of antiherpetic vaccine. If the above signs of exacerbation of the process in the eye after 48 hours are absent, then the injection of the drug is repeated in the same dose after 1-2 days. The diagnostic value of the focal sample is 28-60%, which depends, apparently, on the localization of the inflammatory process in the membranes of the eye. Objectivity for the sake of it should be noted that the sample is considered positive not only with exacerbation of the inflammatory process, but also in the presence of improvement in the state of the eye, which is assessed by applying a number of ophthalmological techniques, starting with the method of biomicroscopy and ending with functional methods of examining the organ of vision. The most evidence-based method for the etiologic diagnosis of herpetic keratitis is the setting of an experiment with a rabbit horn pawn or insertion into the brain of a mouse of a material taken from scraping from an affected human cornea. Development of a clinical picture of herpetic keratitis in a rabbit or the appearance of encephalitis in a patient following the introduction of a material indicates a viral infection.

Significant difficulties are the diagnosis of viral iridocyclitis, proceeding in isolation, without clinical symptoms on the part of the cornea. The role of viral infection in the pathology of the vasculature has not been adequately studied. It is believed that patients with herpetic iridocyclitis constitute 17-25% of the total number of patients with iridocyclitis. The infectious principle can be introduced into the eye in two ways (externally through the epithelium of the cornea and then into the uveal tract and the hematogenous pathway). More often, young people and children. In 17% of cases, iridocyclitis is bilateral and in 50% it recurs. Development of iridocyclitis, as a rule, is preceded by factors characteristic for ophthalmoherpes. These include fever, hypothermia, the appearance of herpetic eruptions on the skin and mucous membranes in various parts of the body. Often, iridocyclitis occurs in the eye, in the past transferred herpetic keratitis. Among the clinical manifestations of herpetic iridocyclitis, as with other types of iridocyclitis, it is possible to distinguish acute and sluggish forms. The acute form is observed less often. It is characterized by sharp painful sensations, expressed by injection of an eyeball of a mixed character, fibrinous effusion into the anterior chamber of the eye. Sluggish clinical form, observed much more often. Differs with unsharp pains or even complete absence of them, a minor injection of the eyeball. It is typical for the appearance of centrally located large precipitates of a sebaceous appearance, fibrinous overlays on the posterior surface of the cornea. Herpetic granulomas in the iris, followed by tissue atrophy at the sites of their localization. At the same iris in the lesions becomes thin, discolored, acquiring a mottled (pockmarked) appearance.

When the granulomas are localized, stromal posterior synechia appears in the pupillary margin. The pupil is resistant to the action of the mydriatic. The process is accompanied by active fibrinous effusion in the vitreous, the development of pronounced turbidity. Iridocyclitis can develop a complicated cataract and, quite typically, a secondary increase in intraocular pressure. With a decrease in the coefficient of ease of outflow of the intraocular fluid and the appearance of gonioscopic changes. Quite often, iridocyclitis occurs with hypervascularization of the iris and a recurring hyphema. Experience of practical work convinces that the hemorrhagic component in the general clinical picture of any iridocyclitis should always be alarming in terms of herpetic infection; other pathogens of the inflammatory process usually do not have this ability to cause vascular reactions.

However, it can not be said that the listed symptoms of viral iridocyclitis were of a purely pathognomic nature. The same changes, expressed to varying degrees, are inherent in serous-fibrinous iridocyclitis tubercular etiology, iridocyclitis, which has developed on the basis of streptococcal infection, iridocyclitis of sarcoidosis. In connection with this, the etiologic diagnosis of herpetic iridocyclitis is not easy. It is necessary to identify other symptoms, in particular, to determine the sensitivity of the cornea, which in herpetic iridocyclitis can be reduced. An important role is played by the statement of a characteristic cytogram of the conjunctiva, which is determined in scrapings from the conjunctival epithelium. A positive reaction of immunofluorescence in the epithelium of the conjunctiva is taken into account when using the appropriate antiherpetic serum.

Finally, we should not forget about the possibilities of intradermal testing with antiherpetic polivaccine. She justified herself in cases of isolated iridocyclitis with a sluggish course and relapses. When staging this allergic reaction, one should remember the possibility of exacerbation of the process in case of herpetic infection, which requires the appointment of desensitizing agents and the intensification of antiviral treatment.

In herpetic iridocyclitis with pronounced neurotropism of the herpes simplex virus, changes in the central and peripheral nervous system, a decrease in tempo adaptation, a change in the visual field of both the patient and the healthy eye can be observed. Herpetic infection from the iris and ciliary body can spread directly along the anatomical extension both anteriorly and posteriorly with the development of the posterior herpes of the cornea and bullous herpetic keratitis, the appearance of focal chorioretinitis, optical neuritis, the periphoebititis of the retina, the secondary exudative detachment of the retina. However, with herpetic infection, the pathology listed does not have any specific differential diagnostic features and can only serve as an aid in the formulation of an etiological diagnosis.

[1], [2], [3], [4], [5], [6], [7], [8],