Symptoms
Keratoconjunctivitis epidemica manifests in the acute phase as annular redness, irritation, and swelling of the conjunctiva with itching, photophobia, severe eye tearing, hemorrhage, foreign body sensation, and eyelid swelling. The symptoms start suddenly in one eye and may spread to the other eye within days. The cornea of the eye may also be affected. The main complication is small corneal opacities, called nummuli, which cause visual deterioration and glare and may persist for months to years. Adenovirus infections of the eye may be accompanied by cold symptoms such as fever, feeling sick, swelling of the lymph nodes, cold and sore throat, especially in children. The disease occurs worldwide and local outbreaks occur regularly.
Causes
The cause is infection with adenoviruses of serotypes 8, 19, and 37, double-stranded, nonenveloped DNA viruses about 90-100 nm in size.
Transmission
Infection is highly contagious and can be transmitted by direct or indirect contact as droplet or smear infection, for example, from eye to eye, by handshaking, via towels, door traps, keyboards and other contaminated surfaces, medical instruments, and eye drops. The viruses can remain infectious for days to weeks. Transmission is common in community settings (e.g., schools, day care centers, military, camps, nursing homes, large offices), and medical personnel may also be affected and contribute to spread, for example, in eye clinics. The incubation period is from a few days to about 2 weeks. Patients are contagious for 2-3 weeks and develop immunity after contracting the disease.
Diagnosis
Diagnosis is made in ophthalmologic care based on patient interview, clinical picture, and direct detection of the causative agent by various laboratory chemistry methods (eye smear). A diagnosis based only on symptoms is controversial because similar symptoms can be caused by other pathogens and causes.
Prevention
Patients should use separate towels or paper hand and handkerchiefs, avoid contact with eyes and others, and wash hands frequently and well. Because of the high risk of infection, patients should stay home and not go to work or school while they are contagious. Appropriate hygienic measures must be taken in eye clinics and doctors’ offices to prevent nosocomial (acquired in medical facilities) infection: Wash hands regularly, wear gloves, disinfect hands and surfaces, disinfect instruments, do not allow eye drop or eye ointments to come into contact with the eye, and never share with another patient.
Therapy
Acute disease usually resolves on its own within 2 to 4 weeks. To date, no antiviral eye drops are available for topical treatment of the disease. Cold compresses, artificial tears, eye gels and analgesics can be used to symptomatically relieve the symptoms. Local sympathomimetics should be used cautiously and if only short-term. Glucocorticoid eye drops are controversial because they are immunosuppressive and cause adverse effects on the eye. In alternative medicine, eyebright eye drops are often used to treat conjunctivitis. Corneal opacities (nummuli) can persist for months to years, but usually disappear on their own. Ciclosporin eye drops, among others, have been studied for treatment, but they are not approved in many countries. They are on the market in the United States for the treatment of dry eye.
