Corneal inflammation (keratitis): causes, symptoms & treatment for inflammation of the cornea

Corneal inflammation is an often underestimated eye disease that can lead to serious damage if left untreated. In this article, you will find out what causes keratitis can have, what symptoms occur and what treatment methods are used to cure it.

What is corneal inflammation?

Corneal inflammation, medically known as keratitis, is an inflammation of the cornea of the eye. The cornea is the clear, dome-shaped outer layer of the eye that focuses light and directs it into the eye, allowing us to see. Inflammation in this area can therefore significantly impair vision and cause serious discomfort.

What causes keratitis – triggers and risk factors that promote inflammation

Keratitis is not uncommon and can occur even with good hygiene. For effective prevention, it is important that you know the main causes of keratitis in order to minimize the risk factors. The most common causes of inflammation of the cornea in the eye are – in no particular order:

Bacterial / viral infection

Bacteria such as staphylococci or pseudomonas can infect the cornea, often through contaminated contact lenses or eye injuries.

Herpes simplex viruses are a common cause of viral corneal infections. These infections can be recurrent and require antiviral medication. Other viruses such as the varicella zoster virus (shingles) can also affect the cornea.

Fungi such as Fusarium or Aspergillus can cause corneal inflammation after injury from plant material or in warm, humid climates.

A rare but serious parasite is the acanthamoeba, which particularly affects contact lens wearers. Treatment is lengthy and requires special antiparasitic medication.

Contact lenses

Wearing contact lenses overnight, poor hygiene or wearing lenses for longer than the recommended time increases the risk of infection. Regular cleaning and correct use are crucial.

Allergic reactions

Allergies to pollen, dust or certain eye drops can cause inflammation of the cornea. Antiallergic eye drops and avoiding allergens are helpful measures.

Dry eyes

An insufficient tear film can dry out the cornea and make it more susceptible to infection and inflammation. Artificial tears and other moisturizing agents help to protect the cornea.

Woman holds her eyes with keratitis

Symptoms of corneal inflammation at a glance:

Keratitis can lead to many – sometimes unspecific – symptoms, which make a quick visit to the ophthalmologist advisable, especially if they occur together. Depending on the causes and stage, the symptoms can be more or less pronounced. Signs of inflammation of the eye are

  • Eye pain (sometimes severe)
  • Redness of the eye: due to inflammation of the blood vessels in the conjunctiva and the surrounding tissue layers
  • Blurred vision: Significant impairment due to swelling
  • Sensitivity to light (photophobia): Pain when exposed to strong light and strong glare
  • Increased production of tear fluid as a defense reaction
  • Foreign body sensation in the eye in the form of itching or burning
  • Discharge of purulent or watery secretions in the case of infection-related keratitis
  • Ulcer on the cornea

If left untreated, corneal inflammation can progress to such an extent that, in the worst case, the eyes can be permanently damaged.

What is the difference to conjunctivitis?

Although both conjunctivitis and keratitis involve inflammation of the eye, they differ in several important ways:

Conjunctivitis affects the conjunctiva, a thin, transparent mucous membrane that covers the inside of the eyelids and the white surface of the eye (sclera).

The causes of these two diseases are varied. Conjunctivitis can be triggered by viruses such as adenoviruses, bacteria such as streptococci and staphylococci, allergens such as pollen and dust or irritants such as chlorine in swimming pools or smoke.

Conjunctivitis is characterized by redness of the eye, itching and burning, lacrimation, discharge of clear, watery or purulent secretions and sticky eyelids, especially after sleeping. In contrast, the symptoms of corneal inflammation are often more severe.

How corneal inflammation is treated:

The treatment of corneal inflammation, also known as keratitis, varies depending on the cause of the inflammation. Rapid and targeted therapy is crucial to protect vision and prevent permanent damage to the cornea.

Bacterial keratitis

Bacterial corneal inflammation requires rapid treatment with antibiotic eye drops. Commonly used antibiotics are fluoroquinolones or combinations of several antibiotics to cover a wide range of bacteria. In severe cases, additional systemic antibiotic therapy may be necessary. The treating physician will often take cultures to identify the specific bacteria and adjust therapy accordingly.

Man uses eye drops to treat keratitis

Viral keratitis

Viral infections of the cornea, especially those caused by herpes simplex viruses, require antiviral medication. Common antiviral agents are acyclovir, ganciclovir or trifluridine. These medications are usually applied as eye drops or ointments. In severe cases or with recurring infections, systemic antiviral therapy may be necessary.

Fungal keratitis

Fungal corneal inflammation requires special treatment with antimycotic medication. Commonly used active ingredients are natamycin, amphotericin B and voriconazole. These medications are administered as eye drops; in severe cases, systemic therapy may also be necessary. The treatment of fungal infections can be lengthy and requires close monitoring by an ophthalmologist.

Parasitic keratitis

A rare but serious form of corneal inflammation is caused by parasites such as acanthamoebae. Treatment includes special antiparasitic drugs, often in combination, such as polyhexamethylene biguanide (PHMB) and chlorhexidine. As the treatment is lengthy and complex, regular check-ups by an ophthalmologist are necessary.

Physical injuries

Injuries to the cornea, such as scratches or foreign bodies, can also cause inflammation. Treatment includes removal of the foreign body, if present, and the use of antibiotic eye drops to prevent infection. Analgesic eye drops and a protective eye patch may also be prescribed.

General measures

Regardless of the specific cause of keratitis, additional measures may be required:

  • Pain relief: Analgesic eye drops or oral painkillers may be prescribed to relieve the discomfort.
  • Anti-inflammatory: In some cases, steroid eye drops can be administered to reduce inflammation. However, these must be used carefully under medical supervision as they can increase the risk of infection.
  • Moisturizing: Artificial tears or moisturizing eye drops can be used to keep the cornea moist and support the healing process.

Corneal inflammation and laser eye surgery: a contraindication

Corneal inflammation (keratitis) is a significant contraindication for laser eye treatments such as LASIK or PRK. This is because active inflammation of the cornea can significantly impede healing. This can also promote scarring. In addition, the inflammation can (temporarily) impair the structure and stability of the cornea, which makes laser eye surgery significantly more risky.
However, the fact that you have had keratitis once does not mean that laser eye surgery is no longer possible. It is only important that the inflammation has been treated, the waiting period has been observed and a thorough preliminary examination has been carried out before treatment.

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Author:

Dr. Victor Derhartunian

Nachdem er sein Handwerk von den beiden Pionieren der Laserchirurgie gelernt hat, gehört Dr. Victor Derhartunian zu den führenden Augenlaser-Chirurgen. Er leitet die Praxis in Wien und kann seine Patienten in fünf Sprachen beraten.