The symptoms and treatment of fungal keratitis

For the first time fungal keratitis was first described in 1979 by Lebaron (Leber). The disease agent is not a common cause of inflammation on the cornea and represents a particular risk in tropical countries. We must not forget about the possibility of a fungal etiology in diseases of the eye, as in the case when diagnosis is delayed, and there is no effective treatment quickly appear irreparable breach in the cornea.

Fungal keratitis is a common term for inflammation in the cornea that are caused by certain microorganisms. These fungi can infect, and thus to cause the inflammation of the outer layers of the eye. The main causative agent is the genus Fusarium in Latin Fusarium, it causes Fusarium keratitis.

The most common pathogens are Aspergillus, they cause of fungal keratitis worldwide. The epidemiology of the disease is associated with climatic features. For example, in southern latitudes is Fusarium lesions, especially with regard to the state of Florida. In contrast, the Northern latitudes are more prone to Candida and Aspergillus keratitis the.

The most common risk factors for fungal keratitis are trauma, use tropical corticosteroids, surgery, chronic keratitis viral nature, as well as shingles and vernal keratoconjunctivitis. Injury, for example, occur when wearing contact lenses or contact with foreign objects. In accordance with studies of morbidity in South Florida (state of USA), in 44% of cases the cause of a disease is trauma completely natural character: banal hit leaves or twigs in the eye. To provoke fungal keratitis can surgery on the cornea of the eye, for example, penetrating keratoplasty or seamless operation of the cornea with cataract laser method of treatment of Keratomileusis called LASIK.

In young healthy men without any significant visible eye diseases can occur fungal keratitis due to a recent injury associated with agricultural work.

Risk factors for development of candidal keratitis include the following: old age, illness eye, other corneal disorders, chronic diseases, chronic keratitis, prolonged use of steroids, suppression of the immune system under the influence of various diseases.

Symptoms of fungal keratitis

Clinically the diagnosis of fungal keratitis can be based onthe results of the analysis of risk factors and on the assessment of the General condition of the cornea.

The most common symptoms of fungal keratitis during the examination using a slit lamp are:

conjunctival injection;
- defects of the epithelium;
- suppuration;
infection of the stroma;
reaction of the anterior chamber;
- hypopyon.

Specific factors of fungal keratitis is the infiltration already raised frilly edges, and extremely uneven texture, with presence of gray-brown pigmentation, with related damage, the presence of coarse granulation infiltration of the epithelium or anterior stroma. There are also white rounded patches on the cornea of the eye and related damage at the edge of the first outbreak of infection with the presence of endothelial plaques.

Treatment of fungal keratitis

Polity very effective against filamentous and yeast fungi, they have a devastating effect against fungi, as embedded in their cell wall ergosterol.

Amphotericin B is the drug of first choice in the treatment of patients with fungal keratitis, which is caused by yeast.

As polity bad enough to penetrate through the tissue of the eye, glubokopronikayuschaya amphotericin B is the best choice in the treatment of fungal keratitis Candida origin. In addition, this drug is highly effective at killing most fungi mizelialnah. To use amphotericin B must according to the strict scheme: the first day – every 30 minutes, on the second day – every hour, then slowly reduce the frequency of administration, already on the basis of the results of treatment.

Natamycin is also used in a wide range of pathogens, given its activity against filamentous fungi. This is the only commercially available drug of the local action of fungal eye. Effective against filamentous fungi, especially the genus Fusarium. Since the drug poorly penetrates into the inner structure of the eye, it is used more when fighting surface infection.

The azole is imidazole and triazole – have as the active substance miconazole, ketoconazole, fluconazole, clotrimazole, intraconazole, econazole. All drugs in this group depressing effect on the synthesis of ergosterol in small concentrations but in significant concentrations have a strong destructive effect on the cell wall.

Oral drugs that are administered orally, fluconazole or ketoconazole, is gradually absorbed and are detected in high concentrations on the anterior chamber and in the cornea, soit is recommended to use them in a more deep fungal keratitis.

Imidazoles or triazoles – synthetic chemical antifungal agents that increase the level of ketoconazole, respectively, of fluconazole in the cornea. This data was discovered during studies of the effectiveness of drugs on animals. Because of the excellent permeability into the fabric of the eye drugs can be used systemically in the treatment of keratitis caused by filamentous or yeast fungi.

Subconjunctival injections required, patients with severe keratitis and keratoscleritis, they are also used in case of poor response to treatment.

To antifungal treatment was successful with keratitis requires frequent administration of drugs over a long period of time (12 weeks minimum).

The primary signs of overdose or toxicity of medications include: indolent ulcer epithelium, erosion expressed on the epithelium of the cornea, diffuse lesions of the stroma.

Patients who do not respond to systemic and local treatment even when using antifungal drugs, surgical treatment is required, it involves the transplantation of the cornea. About 15-27% of patients can not do without surgery. There are some cases when not even surgery helped to restore the vision of patients left blind or preserved other vision problems. Therefore, earlier diagnosis and adequate therapy are very important in the treatment of fungal keratitis.