Synonym
Keratitis
Definition
If the cornea of the eye is inflamed, it is called corneal inflammation. This is less common than conjunctivitis. The two inflammations can also occur together, in which case one speaks of keratoconjunctivitis.
The cornea often appears cloudy. In addition, the eyes water and are very painful. Mostly they are additionally reddened.
The eye can become more sensitive to light (photophobia). The feeling of having a foreign body in the eye as well as burning of the eye also belong to the symptoms. In contrast to conjunctivitis (inflammation of the conjunctiva), the vision can be worse.
It is not uncommon to also have inflammation of the iris (iritis). The ophthalmologist views the eye with a slit lamp. With the Schirmer test, it can be tested how much tear fluid is present.
To do this, small strips of so-called litmus paper are inserted into the lower conjunctival sac in both eyes. After 5 minutes, the length of the paper strip, which is now moistened with tear fluid, is checked. The normal value is 10-20 millimeters per 5 minutes.
If infectious keratitis is suspected, a conjunctival smear can be taken, after which the pathogens can be determined in the laboratory. It is also possible to perform a biopsy. This involves taking a small tissue sample from the cornea.
An ophthalmologist should be consulted immediately if there is any suspicion, otherwise vision may be permanently impaired. The therapy depends on the cause of the corneal inflammation. If the cornea is bacterially affected, for example, antibiotic-containing eye drops are prescribed.
Antimyotics are used for fungal infections, local antivirals for viral origin. Moisturizing eye drops can help with dry eyes. Dexa-gentamicin eye drops are among the antibiotic-containing eye drops.
These combat gentamicin-sensitive pathogens. Hydrocortisone eye drops can be used for chemical causes as well as for physical causes. If scars have formed that cause a permanent deterioration of vision, in severe cases the cornea may detach, making corneal transplantation necessary.
However, this happens very rarely. If treated in time, the corneal inflammation usually heals without long-term consequences. Hydrocortisone eye drops can be used for chemical causes as well as for physical causes.
If scars have formed that cause a permanent deterioration of vision, in severe cases the cornea may detach, making corneal transplantation necessary. However, this happens very rarely. If treated in time, the corneal inflammation usually heals without long-term consequences.
There are many different causes of keratitis. A distinction is made between infectious and non-infectious causes. Infectious causes include infections with pathogens such as bacteria or viruses.
Particularly common bacteria are Staphylococcus aureus, pneumococci and streptococci, common viruses are herpes simplex, adenoviruses and varicella zoster virus. Fungal or amoeba infections can also lead to corneal inflammation. The penetration of pathogens often occurs via contaminated liquids such as contact lens care products or swimming pool water.
This is promoted by wearing contact lenses for too long, which damages the cornea. In general, dry eyes also promote keratitis of infectious origin because the cornea is insufficiently wetted with tear fluid. If the eye cannot be closed properly on a permanent basis, such as through paralysis of the facial nerve, it can also dry out.
An infectious corneal inflammation is contagious. Non-infectious causes include Irritation by chemical substances such as aerosols (for example, steam, smoke or mist) from acids or alkalis. They are more precisely assigned to the chemical cause.
A physical cause is the excessive exposure to UV radiation, as in sunbathing, which irritates the eyes. Mechanical causes are injuries caused by foreign bodies. Keratitis of non-infectious origin do not present a risk of infection.
In the presence of risk factors such as wearing contact lenses, the eyes should be examined regularly. Eliminating risk factors is the best prevention. For example, contact lenses should not be worn longer than indicated and the contact lens case should also be cleaned regularly.
In case of strong UV radiation, care should be taken to wear sunglasses. Excessive work on computer screens should be avoided.Contact lens use is the biggest risk factor for the development of keratitis. Since dry eyes promote keratitis, many causes of dry eyes are also risk factors for keratitis.
These include, for example, dilated eyelid cleft leading to incomplete lid closure (lagophthalmus) or disorders of the facial nerve responsible for lid closure. Various basic diseases such as diabetes mellitus, autoimmune diseases, tumors, sarcoidosis, syphilis or chronic alcohol abuse also increase the risk of developing keratitis. Drugs that suppress the immune system, the so-called immunosuppressants, in turn promote infectious keratitis, since the pathogens can spread better when the immune system is suppressed.