The conjunctiva is the wafer-thin, crystal-clear mucous membrane that covers the front part of the eyeball and the inside of the lids. The conjunctiva can become inflamed in response to pathogens, foreign objects, or irritants. The associated redness in the visible, white part of the eye cannot be overlooked. Conjunctivitis is by far the most common eye disease.
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| conjunctivitis |
Causes, risk factors and frequency
In conjunctivitis, there is a local widening of the blood vessels, which is noticeable as reddening of the conjunctiva, increased production of tears and mucous or purulent secretions, and increased accumulation of water (edema) in the conjunctiva and eyelids. Such an inflammatory reaction is a natural process that serves to render unwanted invaders such as dust particles or pathogens harmless as quickly as possible and to transport them away via the tear fluid. The dilated blood vessels and the increased formation of secretions promote, among other things, the transport of antibodies and the immigration of immune cells to the site of the event. Very different influences from the outside or inside can cause a more or less strong inflammatory reaction in the conjunctiva.
Pathogens
Infection-related conjunctivitis is mainly caused by adenoviruses. These are viruses that can also cause general cold symptoms such as cough, sore throat or fever. Adenoviruses are often highly contagious and can spread like epidemics in the population (conjunctivitis epidemica). Infection can occur via droplet infection, i.e. via viruses that get into the air when you cough or sneeze. The pathogens can also be transmitted through skin-eye contact or touching infected objects.
Other viral infectious diseases can also be associated with conjunctivitis; this is very often the case with measles, for example. Infections with herpes viruses are rarer but more complicated. Bacterial conjunctivitis is much less common than viral. In very few cases is a fungal infection behind it. Anyone who suffers from a limited immune system, for example due to illness, age, frailty or taking certain medications, is particularly susceptible to infections and thus also to infection-related conjunctivitis.
Allergies
Hay fever (pollen allergy) is often accompanied by pronounced conjunctivitis. It is also a frequent companion in neurodermatitis (atopic eczema) and other allergic diseases.
Other diseases
Increased intraocular pressure, dry eyes, inflammation and injuries to other parts of the eye are regularly associated with conjunctivitis. Inflammation of the middle layer of the eye (uveitis), which practically always spreads to the conjunctiva, can be caused by an infection, but can also indicate an inflammatory rheumatic disease (rheumatism) or another chronic inflammatory disease. Diseases of the nervous system, which are associated with visual disturbances or paralysis of the eye muscles, are also among the possible causes of conjunctivitis.
Mechanical and chemical stimuli
Wind, dust, smoke, foreign objects, intense UV radiation and irritants such as chlorine or ozone can all trigger conjunctivitis. Treatment beyond avoiding the cause is usually not necessary, as the symptoms resolve on their own. Some people react - presumably hereditary - particularly easily to such stimuli and therefore have conjunctivitis more frequently. This is often particularly pronounced in adolescence and young adulthood and decreases with age.
Symptoms
Has the visible part of the conjunctiva turned blood-red in one or both eyes?
Do you feel a slight burning sensation there or a foreign body sensation?
Does the affected eye water and secrete a clear or yellowish, slimy secretion?
Then this indicates conjunctivitis. The redness is caused by the emergence of fine veins. Up close you can see the dense network of blood vessels. Eyelids are often swollen and sticky when you wake up. Depending on the cause of conjunctivitis, symptoms may vary somewhat. Yellowish-white, purulent secretion indicates bacteria. Conjunctivitis caused by an allergy is almost always accompanied by swollen, itchy eyelids; eyelid swelling is less pronounced in bacterial infections and very slight in viral infections. Swollen and tender cervical lymph nodes are common with viral conjunctivitis, occasionally with bacterial, but not with allergic ones. In allergic conjunctivitis, both eyes are affected from the start, accompanied by severe itching. Viral and bacterial infections can initially affect only one eye and later spread to the other.
Red eyes are not always harmless
If you have red and itchy eyes from repeated hay fever attacks and are already being treated, you don't need to worry. Reddened eyes after swimming in the sea or in chlorinated swimming pool water are completely normal and nothing to worry about. However, if the symptoms appear "out of the blue" and without a clear cause, you should consult an ophthalmologist immediately. On the one hand, some pathogens do not stop at the borders of the conjunctiva, but can spread to other parts of the eye or other organs and cause considerable damage there; on the other hand, red, watery eyes can also indicate other, more serious eye diseases. Only the ophthalmologist can tell the difference with certainty with the help of apparatus-based examinations.
When to the doctor?
You should seek medical treatment immediately
- in the event of new or increasing visual disturbances.
- with pain in the depth of the eyeball.
- with accompanying facial pain or headache.
- with purulent secretion.
- if you have already been diagnosed with increased intraocular pressure (glaucoma, glaucoma).
- with a unilaterally enlarged or reduced pupil.
- when the reddening of the conjunctiva is in patches sharply demarcated from the white parts of the eye.
Call an ambulance immediately!
Sudden circulatory disorders of the optic nerve and the central nervous system as well as a stroke can also be accompanied by unilateral reddening of the conjunctiva, among other things.
Reasons to call an ambulance immediately include:
- Sudden visual disturbances with severe pain in the eye
- One-sided sensory or movement disorders in the face
- Suddenly hanging eyelid or eyelid that can no longer be closed completely
Treatment
The treatment of conjunctivitis is based on the cause of the disease.
Viruses
There are no effective drugs against the most common cause of viral conjunctivitis - adenoviruses. Since the infection usually runs its course without complications and almost always stops by itself, treatment is not necessary.
Rarely, conjunctivitis is caused by infections with herpes simplex viruses, the causative agent of cold sores, or with herpes zoster viruses, the causative agent of shingles and chickenpox. Then other parts of the eye are usually affected in addition to the conjunctiva, and immediate treatment with antiviral drugs is important to avoid consequential damage.
Bacteria and fungi
Although bacterial conjunctivitis usually subsides without treatment within a maximum of three weeks, with broad-spectrum antibiotics, which are usually administered locally in the form of eye drops, freedom from symptoms can usually be achieved in one to two days. Rarely, fungal infections are the cause of conjunctivitis. Then, instead of antibiotics, special antifungal eye drops are used.
Bacterial conjunctivitis is rarely caused by chlamydia or gonococci - the pathogens that cause gonorrhea (gonocles). Both types of bacteria can also infect the genitals, among other things, triggering purulent inflammation there and subsequently leading to organ damage. Conjunctivitis caused by chlamydia or gonococci requires several weeks of treatment with antibiotic tablets or capsules and usually also treatment of the intimate partner.
Allergies
The treatment of allergic conjunctivitis - for example in the context of hay fever - follows the same principle as the treatment of the underlying allergic disease. This includes the consistent avoidance of the allergy trigger (allergen), the usual antiallergic agents, for example in the form of eye drops, and, if necessary, a desensitization treatment.
General Measures
- Cool pads are intended to relieve burning and itching and to help reduce swelling in the eyelids. Because they have virtually no risk of side effects, you can try them with confidence.
- Eye rinsing with a physiological saline solution can remove pathogens and allergens and thus provide relief. However, they carry the risk of introducing germs and transmitting the infection from the diseased to the healthy eye, especially if used improperly.
- Artificial tears are available as eye drops or gels. If you find their use pleasant, then there is nothing to be said against it. However, choose a preparation without preservatives to avoid allergic reactions. The risk of introducing germs into the eye is lowest with separately packaged unit doses.
- Although disinfecting eye drops are approved for the treatment of bacterial conjunctivitis, their effectiveness in this area of application has not been proven without a doubt. They can also trigger allergies. Antibiotic eye drops are therefore usually preferable.
- Vasoconstrictive agents (sympathomimetics) are used exclusively to relieve symptoms and are only harmless if used for a short time.
- There are indications that herbal medicine (phytotherapy) preparations, such as eyebright, the application of black tea bags or plant extracts from traditional Persian-Arabic medicine, alleviate the symptoms of conjunctivitis. However, chamomile in particular and, more rarely, other medicinal plants can trigger eye allergies.
- Glucocorticoid eye drops have a strong anti-inflammatory effect and thus relieve the symptoms of conjunctivitis. In the case of particularly severe and protracted courses, their use is essential in order to avoid damage to the eye. However, these drugs inhibit the body's own defenses against the pathogens and can thus promote their spread. In no case should they be used for herpes infections.
Prevention
In order to prevent the spread of the highly contagious adenoviruses, infected people should not visit any public facilities such as schools or kindergartens. Both those affected and those with whom they are in contact are advised to wash their hands carefully - especially after contact with the eyes or infected nasal secretions. In general, it is advisable not to touch your face, especially your eyes, as much as possible. Pillowcases, towels and washcloths should not be shared with others. Since herpes conjunctivitis is associated with a comparatively high risk of complications, one should be particularly careful with herpes on the lips and in the genital area to avoid introducing germs from the herpes blisters into the eye - for example via washcloths, towels or involuntary touching.
Allergic, mechanical or chemical conjunctivitis can only be prevented by avoiding the relevant allergens or irritants or other eye-irritating influences such as drafts or strong UV radiation - for example with the help of sunglasses. Remember that medication or cosmetics applied near the eyes can occasionally cause conjunctival irritation or allergic reactions.