Conjunctivitis is an eye disease and is also known as conjunctivitis. The conjunctiva is affected. This is the thin mucous membrane of the eye that covers the inside of the eyelids and partly the eyeball. In conjunctivitis, this conjunctiva is inflamed or irritated.
In principle, there are two types of conjunctivitis:
- contagious, infectious conjunctivitis (caused by bacteria, viruses or fungi), and
- non-infectious conjunctivitis (usually caused by allergies or external influences).
The conjunctiva has many blood vessels and reacts to inflammation and irritation with increased blood flow. Red eyes are therefore the main symptom of conjunctivitis.
Red eyes are the main sign of conjunctivitis © Birgit Reitz-Hofmann
Conjunctivitis is one of the most common eye diseases and the main cause of red eyes.
Children and infants are particularly frequently affected, as highly contagious forms of conjunctivitis caused by viruses can spread quickly in nurseries and schools.
Conjunctivitis can have both infectious and non-infectious causes.
The infectious form of conjunctivitis is very contagious and can be caused by various pathogens. The possible causative bacteria include
- Gonococci,
- pneumococci,
- staphylococci and
- chlamydia.
Viral pathogens that frequently trigger conjunctivitis include
- Adenoviruses,
- herpes viruses,
- influenza viruses and
- zoster viruses.
The most common non-infectious causes of conjunctivitis include allergies and external environmental stimuli. This form of conjunctivitis is not contagious. For example, allergies to pollen, food or medication can cause conjunctivitis. External stimuli that are often responsible for conjunctivitis are mainly
- Draughts (e.g. when driving with the window open),
- Foreign bodies or dust in the eye,
- smoke (e.g. when staying in heavily smoky rooms) or
- ultraviolet light (e.g. during winter sports or overexposure to the sun).
In some cases, conjunctivitis can also occur as a concomitant symptom of other eye diseases. These include
- Diseases of the tear ducts, such as constricted or blocked tear drainage ducts,
- recurrent eye inflammation and
- so-called "dry eye", which occurs when the natural protection on the surface of the eye, the tear film, is disrupted.
Conjunctivitis can manifest itself through various symptoms, depending on the cause. The main symptom of conjunctivitis is reddened eyes, as described above. The conjunctiva reacts to inflammation and irritation by increasing the blood supply to its many blood vessels.
Other common symptoms are
- Increased tear production,
- itching or burning in the eye and
- a feeling of pressure in the eye.
In addition, the conjunctiva and sometimes the eyelids are swollen. The eye may secrete a watery, whitish-yellow, mucous or purulent secretion. This can lead to sticky eyelids, especially in the morning. Increased sensitivity to glare or light is also possible
In addition, there is often a foreign body sensation: those affected have the feeling that there are grains of sand in the eye that rub against each blink.
The ophthalmologist can easily make a diagnosis based on the typical symptoms. However, simply making a diagnosis is not enough. For targeted treatment, it is necessary to identify the cause and spread of the disease.
To do this, the doctor first examines the eye and the inside of the eyelids with a so-called slit lamp. This enables a magnified view of the eye under a specific light. He also examines the visual acuity and, if necessary, the back of the eye.
If bacterial conjunctivitis is suspected, the doctor will take a swab from the conjunctiva. The smear is then examined. The bacterial pathogen causing the disease can be determined in the laboratory. Such a conjunctival swab can also rule out conjunctivitis caused by viruses or allergies.
An allergy test can also clarify whether a specific allergy has caused the conjunctivitis. If necessary, other diagnostic procedures can also be used. They then serve to rule out other serious eye diseases as the cause.
The treatment of conjunctivitis depends on
- the severity
- the course and
- particularly the trigger of the disease
of the disease. Only when the causes of conjunctivitis are known can the ophthalmologist prescribe the appropriate medication.
Eye drops or ointments containing antibiotics are generally used for bacterial conjunctivitis. They are designed to kill the pathogens. Severe conjunctivitis can also be treated with ointments containing cortisone if necessary.
Artificial tear substitutes in drop or gel form can help with inflammation caused by a dry eye. They are injected into the conjunctival sac and help to moisten the surface of the eye. Such tear substitutes can also be used to alleviate symptoms caused by external stimuli such as dust, strong sunlight or allergens.
Allergy-related conjunctivitis can be treated with special eye drops containing an anti-allergic agent. In this case, it is also advisable to avoid the substances that trigger the allergy (the so-called allergens) as far as possible.
Conjunctivitis caused by herpes or zoster viruses is usually treated with the active ingredient acyclovir. It suppresses the multiplication of the viruses.
Conjunctivitis caused by cold viruses as part of a cold usually requires no treatment.
The burning and itching in the eyes caused by conjunctivitis can be relieved by applying cold compresses . Cotton pads or compresses can be used for this purpose.
Conjunctivitis caused by infection can be prevented by washing your hands regularly. This can prevent infection, especially after contact with someone who is already suffering from conjunctivitis. If you suffer from an allergy that can trigger conjunctivitis, you should avoid contact with allergy-triggering substances (e.g. animal hair). Taking anti-allergic medication in good time can help against allergens such as pollen, which occur seasonally.
People with dry eyes should make sure they drink enough fluids (around 1.5 to 2 liters a day). Sunglasses protect the eye from conjunctivitis caused by strong sunlight (e.g. when skiing), dust, smoke or draughts. Contact lenses should be cleaned regularly and carefully. Avoiding overexertion of the eyes due to prolonged computer work or lack of sleep can also prevent conjunctivitis.
Conjunctivitis that is due to known causes such as allergies, a cold, draughts or smoke does not necessarily need to be examined by a doctor. In this case, those affected can use tear substitutes and wait to see if the symptoms subside.
However, red eyes can also hide serious eye diseases and bacterial infections that require qualified treatment. You should therefore consult an ophthalmologist immediately if you experience the following symptoms:
- sticky yellowish secretion secreted from the corners of the eye,
- visual disturbances, such as blurred vision or sudden "blind spots",
- severe and deep eye pain,
- accompanying symptoms such as fever, nausea and vomiting.
