Acanthamebic Keratitis: Symptoms And Treatment Of The Disease

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Acanthamebic Keratitis: Symptoms And Treatment Of The Disease
Acanthamebic Keratitis: Symptoms And Treatment Of The Disease
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Any water is a source of pathogenic microbes, among which the single-celled protozoa Acanthameba are distinguished. These parasites are the causative agent of an infectious and inflammatory disease - acanthamoebic keratitis, which poses a great danger to vision. As a rule, people who use contact lenses are prone to the inflammatory process. But there are exceptions when the disease occurs in people who do not have visual impairment, namely from mechanical damage to the eye.

Content

  • 1 The reasons for the development of the disease
  • 2 Risk factors
  • 3 Signs
  • 4 Stages of acanthamoebic keratitis
  • 5 Diagnostics
  • 6 Therapy

The reasons for the development of the disease

The causative agent of acanthamoebic keratitis lives in almost any aquatic environment, including tap water. They can be found in saunas, swimming pools and even showers. Most often, parasites get onto contact lenses with contaminated water. You just need to take a shower in them. Also, infection can occur due to improper care of lenses and neglect of the rules for disinfection.

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In addition, acanthamoeba are able to instantly penetrate into the connective membrane of the eye, in the presence of even minor microtraumas. Keratoconjunctivitis dry (dry eyes) can cause acanthamoebiasis. Since this pathology involves a deficiency of lacrimal fluid, which is essential for the immunity of the organ of the visual system.

The protective immune response of the eye is also weakened in people with diabetes mellitus, which favors the penetration of pathogenic agents. At risk are those people who have undergone any surgical interventions on the eyes, since the protective functions of the cornea are restored for a long time. That is, any damage to the conjunctiva of the eye is a gateway for microbial agents that provoke a variety of inflammatory processes.

Risk factors

Acanthamebiasis is quite rare in people who do not wear contact lenses. Protozoal disease is an adverse consequence of improper lens use. Reasons that increase the likelihood of developing an infection include:

  1. Using running water or water from springs to clean contact lenses.
  2. Storing contact lenses in a contaminated container.
  3. Using homemade homemade lens storage solutions.
  4. Swimming in any water with lenses put on (pool, shower, sauna, jacuzzi).

Penetrating with contaminated water into the conjunctiva of the eye, parasites of the genus amoeba produce a special protein that allows them to cling to the cornea of ​​the eye. Further, acanthamoebas activate enzymes that contribute to the destruction of the basic substance of the cornea and its cells. This inflammatory course allows microbes to move into the deep layers of the conjunctiva, causing peripheral corneal thinning.

Signs

Symptoms of acanthamoebiasis can occur in two eyes at the same time. The most common symptoms include: severe swelling of the mucous membrane of the eye, cutting pain, photophobia, blurred vision, tearing, and pain when removing contact lenses. The appearance of such signs indicates the presence of an infection in the eye and calls for immediate medical attention.

Stages of acanthamoebic keratitis

Acanthamebic keratitis has stages, each of which is characterized by the degree of corneal lesion:

  1. Stage 1 - superficial epithelial keratitis.
  2. Stage 2 - superficial punctate inflammation of the cornea of ​​the eye.
  3. Stage 3 - deep annular inflammation.
  4. Stage 4 - corneal ulcer.
  5. Stage 5 - keratoscleritis.

Diagnostics

There are times when even a qualified specialist is not able to diagnose the disease in time. By mistake, they make the wrong diagnosis (bacterial inflammation of the cornea) and prescribe drugs that subsequently do not have any therapeutic effect in case of acanthamoeba damage. Acanthamebiasis is also difficult to diagnose due to similar symptoms with other types of keratitis.

Confirmation of the diagnosis occurs on the basis of the cultural research method: the pathogen is detected in biological materials (tissues) or scrapings from the surface of the cornea after sowing them on a special nutrient medium. Also, staining of a scraping from the cornea is carried out for further examination using a microscope. An effective method is the reaction of immunofluorescence (RIF).

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To date, for the diagnosis of this disease, molecular biological methods are often used, including the polymerase chain reaction, since they can reveal even a small number of pathogens.

Acanthamebiasis is effectively detected using confocal laser scanning microscopy (CLSM), a category of light optical microscopy. This method allows you to identify both the pathogens themselves and their cysts in the main substance of the cornea.

Therapy

The treatment of corneal inflammation caused by amoebae is complicated by the fact that these parasitic unicellular organisms are highly resistant to the use of antimicrobial drugs. Therefore, this pathology is difficult to treat. In most cases, only in the early stages of the disease is there a chance to preserve vision and prevent surgery. When the disease is detected at advanced stages, there is a risk of the need for an operation such as penetrating keratoplasty (corneal transplant). However, even surgical intervention does not guarantee that vision will remain.

Conservative treatment includes the use of eye drops, the duration of which is several months. Drip injection of the drug in the first two days is carried out every hour. Over the next months, eye drops are applied every six hours. Along with this, the patient is prescribed drugs such as: antiseptics, antimycotics (ketoconazole, fluconazole), antibiotics (moxifloxacin, tobramycin), corticosteroid drugs that enhance the therapeutic properties.

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Surgical treatment is indicated for the formation of corneal ulcers. This could be:

  1. Transplant, cornea transplant.
  2. Donor cornea transplant.
  3. Layer-by-layer transplantation of the superficial layers of the cornea using a conjunctival flap.
  4. Deep layered cornea transplant.
  5. FTK (phototherapeutic keratectomy).

Acanthamebic keratitis is a dangerous infectious disease that can cause complete blindness and even loss of an eye. The treatment of this pathology is a complex process that requires constant monitoring by the attending physician, in a systematic correction of the doses of drugs used, depending on the patient's response to them.

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