Keratomycosis: causes, symptoms, diagnosis, treatment

Increased in recent years, fungal diseases of the cornea, often proceeding hard and with a bad outcome, are of leading importance in the fungal pathology caused by the organ of vision. Diagnosis and treatment of them are difficult. In the development of these diseases, the first place belongs to aspergillas, followed by cephalosporiums, candida, fusarium, penicillium and other fungi. In the majority of cases, fungal keratitis is primary, since the parasite comes from the outside, often infiltrated by small corneal injuries caused by plant and other damaging agents.

The disease occurs more easily and is more difficult for people with reduced resistance due to diabetes mellitus, anemia, liver cirrhosis, radiation therapy, leukemia, and chronic irritation of the conjunctiva. Sometimes mushroom damage is layered on herpetic keratitis, spring catarrh, other corneal diseases, aggravating their severity and making diagnosis difficult.

The clinical picture of mycotic processes developing in the cornea largely depends on the type of pathogen preceded its introduction, the state of the eye and the body, their reactivity, the stage of the disease.

Most often there is and therefore more known fungal ulcer of the cornea, caused by molds and other fungi. Occupying this or that part of the cornea, more often its center or paracentral site, such an ulcer begins with the appearance in the subepithelial or deeper layers of the stroma of the discoid yellowish-gray infiltrate, which quickly turns into a disk-shaped, ring or oval ulcer with a diameter from 2-3 to 6-8 mm. The edges of the ulcers are raised and protrude a grayish-yellow shaft, and the center looks gray, uneven, dry, sometimes with a mound of crumbly particles or a whitish curdled coating. When staining with fluorescein, a deeper tissue defect is detected along the inner perimeter of the surrounding shaft ulcer. Sometimes infiltration diverges from this shaft in all directions, giving the ulcer the most characteristic appearance. However, more often there is no such radiance, but a semi-transparent zone of the intra-horny infiltrate is determined biomicrostrictly around the ulcer, folds of Descemet's membrane, precipitates are visible.

In 1 / 3-1 / 2 patients, the ulcer is accompanied by hypopion. Irritation of the eye is expressed sharply from the very beginning of the disease, often there is serous-plastic or plastic iridocyclitis. Later the ulcer acquires a chronic course, has no tendency to spontaneous healing, does not lend itself to antibacterial therapy. In a number of cases, with or without this treatment, the ulcer extends to the depth, perforates the cornea, and can end with endophthalmitis.

For quite a long time the disease proceeds without vascular growth in the cornea, then sooner or later, if antimycotic therapy is not started, the vessels appear in different layers of the stroma, surround the ulcer and grow in the dog. The danger of perforation in such cases decreases, and gradually the vascularized leukoma is formed.

The sensitivity of the diseased cornea is disturbed rather early, especially around the ulcer, but remains on the healthy eye, which distinguishes the fungal infection from the viral infection.

In some patients, the fungal corneal ulcer from the very beginning appears to be similar to a creeping ulcer: an undercut infiltrated edge is formed, the tissue defect quickly spreads in width and depth. The similarity with ulcus serpens is enhanced by a high viscous hypopion, a pronounced irritation of the eye.

The surface keratomycosis, more often caused by Candida albicans, is easier to flow and less. According to G. X. Kudoyarova and MK Karimova (1973), in these patients appear on the cornea epithelium rising above Similar to dust particles, larger dots or friable lumps bizarre shapes infiltrates grayish white color. They are easily removed with a wet fleece, but the epithelium beneath them is thinned or depleted. Irritation of the eye is moderate; without treatment, infiltrates quickly reappear. They can also have the appearance of dense white plaques, which grow into the depth and are necrotic with the formation of fistulas of the cornea.

In the diagnosis of keratomycosis, anamnesis and clinic of the disease, torpidity of its course, resistance to antibacterial and other therapy are of great importance. Most accurately, ethnology is recognized on the basis of the results of microscopic examination of smears, scrapings, biopsies, trephine in keratoplasty, sowing this material on special media, infecting animals.

Histologically, mycosis of the cornea is characterized by signs of chronic inflammation, in particular predominantly lymphocytic infiltration between the layers of the stroma, where the fungal mycelium can also be detected. More often the pathogen is identified, identified and tested for sensitivity to medicines in growing cultures, and the infection of animals confirms its pathogenicity. If such diagnostics are not possible, trial treatment with antifungal agents can help to recognize the fungal lesion.

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

Treatment of conjunctival mycoses

Treatment is carried out by the above fungicidal antibiotics, iodine and other drugs, which are prescribed topically and inward, less often injected parenterally. For local therapy, only the eye forms of these agents are suitable, when using which one can adhere to different schemes. For example, some ophthalmologists recommend that during the day, every 2 hours instill a solution of nystatin (100,000 units in 1 ml), in the evening pawn of 1% pimaricin ointment, and in order to influence the possible concomitant bacterial flora three times a day instill antibiotic solution. When isolating the pathogen, the means to which it is sensitive are used. However, it should be remembered that not always detectable fungus is guilty of eye disease; it can only be one of the conjunctival saprophytes that are found here quite often. Thus, B. Aniey et al. (1965) found such saprophytes in 27.9% of patients admitted to cataract extraction, and in 34.6% of patients with conjunctival and non-mycotic corneal disease.

Treatment of keratomycosis

Treatment consists in therapeutic and other effects on the foci of infection in the cornea and the general purpose of mycostatic drugs. The use of scraping of fungal ulcers and infiltrates or the elimination of them by other mechanical methods has not lost its value. When scraping (removal trepapom, tampon, etc.), cleared from mycotichskogo substrate and necrotic masses, the corneal area is extinguished with 5-10% alcohol solution of iodine or iodoform, dust powder amphotericin B. Sometimes resort to cauterization of ulcers. Already the first stamping brings relief to the patient and stops the process. The scraping is preceded and followed by instillation into the conjunctival sac of 0.15-0.3% amphotericin B solution every 0.5-1 h in the first 2-3 days, then 4 times a day. Inside give nystatin in a dose of up to 1 500 000-2 000 000 units per day, levorin. In severe cases, intravenous amphotericin B is indicated. An old proven drug for the treatment of fungal infections of the cornea remains potassium iodide, 2 to 10 g of which is administered daily inwards. You can enter a 10% solution in a vein, eh? In a conjunctival bag to instill 1-2% solution. Treatment "is conducted in the hospital for 4-6 weeks.

Actinomycetes show broad-spectrum antibiotics, sulfonamides.

The efficacy of topical therapy can be increased by electrophoresis of mycostatic agents, in particular sodium nystatin and sodium levorin, via the baths (10,000 units per 1 ml, from the cathode at a current of 0.5-4 mA, 10-15 min, daily, for a course of 15 procedures) . According to Karimov and Valiakhmetov (1980), who developed this method of treatment in 45 patients, it is much more effective than instillations of the same drugs. In case of foreses, the analgesic effect, fungicidal action, stimulation of immunogenesis, preparations penetrate deeper into the corneal tissue. In addition to antifungal therapy, patients with keratomycosis receive symptomatic treatment (midria.tiiki, keratoplastic agents, etc.). Heat, like hypertensive solutions of sodium chloride conjunctiva, is shown only in severe manifestations of the complicating disease iridocyclitis. To eliminate the possible bacterial flora in the first week of treatment should be administered antibiotics. Therapeutic or therapeutic combined with mechanical treatment is most successful with superficial lesions of the cornea with fungi. The introduction of an infection deeper than 2/3 of its stroma requires more action. As shown by LK Parfenov and MK Karimov, FM Polack and co-authors G. Giinther and many other authors, only a layered or through, partial or total keratoplasty can save the eye from death with deep mycosis of the cornea, that it was undertaken in a timely manner, carried out with complete elimination of lesions and in combination with anti-mycotic therapy. Less often resort to conjunctival covering of the cornea or supplement them with keratoplasty.