Diphtheria conjunctivitis is an acute infectious disease characterized by fibrinous inflammation of the conjunctiva. Clinical manifestations include hyperemia, chemosis and the formation of dense grayish films, when attempting to remove which bleeding develops. Specific laboratory tests (latex agglutination reaction, bacteriological examination), biomicroscopy of the eye, visometry and ophthalmoscopy are used for diagnosis. Treatment is reduced to the appointment of anti-diphtheria serum, antibacterial agents, antiseptics, keratoprotectors and vitamins.
Diphtheria conjunctivitis is a bacterial inflammation of the mucous membrane of the eye that develops when infected with Klebs-Leffler bacteria. Isolated conjunctival lesion is extremely rare in modern ophthalmology. Often, the eye is involved in the pathological process in combination with the upper respiratory tract. According to statistics, the croup form occurs in 80% of cases, catarrhal – in 14%, diphtheria – in 6%. The disease is most often diagnosed in children aged 2-10 years. Pathology is widespread everywhere.
Diphtheria conjunctivitis develops when infected with Klebs-Leffler’s bacillus (Corynebacterium diphtheriae). The source of infection is a sick person or a passive bacterial carrier. The main transmission mechanism is airborne. Cases of infection by contact and household means are described, realized when using someone else’s personal hygiene products and touching the ocular area with contaminated hands. An important role in the spread of the infectious process is assigned to erased and atypical forms of diphtheria. The risk of infection is highest during epidemic outbreaks of the disease.
The Klebs-Leffler stick maintains stability in the environment and under the influence of low temperatures. The use of disinfectants and heating up to 60 ° allows you to destroy the pathogen. The infection is characterized by high contagiousness. A person secretes bacteria even during the period of convalescence. After the infection, a persistent antitoxic immunity is formed. During the first year of life, protection from diphtheria is provided by antibodies that are transmitted by the transplacental route from the mother.
Diphtheria bacillus is a gram–positive bacterium that produces a potent exotoxin. The action of the toxin leads to necrosis of the epithelium and the release of thrombokinases. This causes increased permeability of the vascular wall. The exit from the vessels of plasma rich in fibrinogen, followed by sweating of the conjunctiva and the subconjunctival layer leads to the formation of films. The fibrinous film is tightly soldered to the underlying tissues, which entails a violation of metabolic processes and the formation of scar adhesions.
Diphtheria conjunctivitis is an acquired pathology of bacterial genesis, which is characterized by an acute course. The disease may be one of the local manifestations of diphtheria or develop in isolation. The toxic form includes diphtheria inflammation. Croup and catarrhal lesions are considered non-toxic. Clinical features of pathogenetic forms:
- Diphtheria. A severe variant of the disease, in which there is swelling and compaction of the eyelids, followed by the formation of scar defects. In 46% of cases, it is accompanied by the development of dangerous consequences, often leading to irreversible changes in the conjunctiva and eyelids.
- Krupoznaya. A more favorable type of inflammation. Fibrinous films in rare cases extend to the zone of transitional folds. Subsequently, scars are not formed. The main place of localization of the pathological process is the mucous membrane of the eyelids.
- Catarrhal. The easiest form. Local changes and fibrinous films are not detected. After the pathology is resolved, the conjunctiva looks intact, so the catarrhal type of the disease often goes unnoticed.
The pathology is characterized by a one-sided course. On the side of the lesion, there is an increase in regional lymph nodes (submandibular, parotid). A complicated course of infection is characterized by an increase in body temperature, headache and general weakness. To detect the corresponding changes, it is important to examine other target organs that are affected by diphtheria (oropharynx, larynx, nose, skin). The clinical picture of conjunctivitis largely depends on the form of inflammation.
With diphtheria type, due to pronounced swelling and compaction of the eyelids, patients cannot open their eyes. On 3-5 days after the onset of the first symptoms, the eyelids become softer. Patients note the appearance of mucopurulent discharge. When opening the eye slit, it is possible to identify gray films that are visualized in the area of cartilage and transitional folds. In severe cases, plaque is detected even on the orbital conjunctiva and the skin of the eyelids. Fibrinous films are so strongly soldered to the underlying tissues that an attempt to remove them is accompanied by bleeding. As the disease resolves, scars form on the conjunctiva.
With a coarse form, the films are located in the area of the palpebral conjunctiva and are clearly limited by a transitional fold. Fibrinous layers are delicate, grayish in color. When removing the films, a defect forms in their place, which bleeds slightly. The surface of the eyeball remains intact. With catarrhal inflammation, fibrinous films are not observed. The mucous membrane is hyperemic and edematous. Patients complain of redness and puffiness of the eyes. The general condition is not disturbed.
Severe course of diphtheria conjunctivitis leads to dangerous complications. The most frequently formed pathological junctions between the orbital and palpebral conjunctiva (simblefaron). A common consequence is entropion. Abnormal growth of eyelashes leads to permanent irritation of the conjunctiva and cornea. A formidable complication of diphtheria eye damage is a corneal ulcer with a high risk of perforation. When the infection spreads to the deep structures of the eye, panophthalmitis develops.
The basis for a preliminary diagnosis is epidemiological data (contact with a patient with diphtheria or a bacterial carrier for 14 days), the results of a biochemical blood test and the detection of fibrinous layers on the conjunctiva. In peripheral blood, leukocytosis, neutrophilosis with a shift of the leukocyte formula to the left and an increase in ESR are determined. Specific diagnostic methods include:
- Visometry. Diphtheria conjunctivitis does not lead to deterioration of visual functions, however, with corneal edema, there is a slight decrease in visual acuity. Additionally, computer refractometry or skiascopy is shown.
- Biomicroscopy of the eye. When examining the anterior segment of the eye with a slit lamp, it is possible to detect corneal edema and chemosis. Dense dirty-gray films are visible on the palpebral conjunctiva. The marginal edge of the eyelids with the diphtheria nature of inflammation is thickened.
- Examination of the fundus. Ophthalmoscopy is a mandatory part of the examination of a patient with bacterial conjunctivitis. The purpose of ophthalmoscopy is to exclude secondary complications from the posterior segment of the eyeball and optical media.
- Laboratory diagnostics. If diphtheria conjunctivitis is suspected, a latex-agglutination reaction is produced. This is an express method that allows you to get the result in 2 hours. To determine the toxigenicity and biovar of the pathogen, the use of a bacteriological method is recommended.
If the patient has specific signs of the disease, hospitalization in the infectious department is indicated. Etiotropic therapy is reduced to intramuscular administration of antidiphtheria serum. With a local lesion of the conjunctiva, a one-time use of serum at a dose of 10-20 thousand IU is recommended. The treatment package includes:
- Antibacterial agents. The expediency of systemic use of antibiotics from the group of penicillins or macrolides has been proved. Every 2-3 hours, instillations are carried out into the conjunctival cavity of a benzylpenicillin solution in the form of eye drops. Erythromycin ointment is placed under the eyelids 2-3 times a day.
- Keratoprotectors. Drugs of this group are prescribed when signs of damage to the cornea are detected. Corneal regeneration is promoted by medicines based on pantothenic acid. It should be noted that keratoprotectors in the form of ointment or gel should be used no earlier than 15-20 minutes after instillation of drops.
- Antiseptics. Antiseptic solutions are used to wash the conjunctival cavity 6-8 times a day. Medicines increase the effectiveness of topical use of antibiotics, have anti-inflammatory and immunoadjuvant effects.
- Vitamin therapy. Eye drops containing ascorbic acid and riboflavin are recommended for diphtheria conjunctivitis. They are prepared on the basis of glucose immediately before instillation. Additionally, a 3% retinol acetate solution is prescribed for topical application.
Prognosis and prevention
The outcome of the disease depends on the nature of the infection. With diphtheria, there is a high risk of developing dangerous complications that lead to significant changes in the conjunctiva of the eyelids and eyeball. With croup and catarrhal diphtheria conjunctivitis, the prognosis is favorable. Specific prevention is reduced to vaccination. Modern vaccines are developed on the basis of diphtheria toxoid. Non-specific preventive measures are aimed at isolating patients with diphtheria, timely immunization of contact persons, and final disinfection in the focus.