Keratitis: Symptoms, Types, Causes, Diagnosis, Treatment, Prognosis and Prevention

It is an inflammatory condition that affects the cornea of ​​the eye.

The cornea is the transparent part that covers both the iris and the pupil. Keratitis can be caused by an infection or injury to the eye .

Keratitis is a common condition, people who wear contact lenses may experience keratitis more often than people who do not wear contact lenses.

In either case, you can take steps to help prevent this condition. If you develop keratitis, see your doctor immediately.


Symptoms of keratitis include:

  • Red eyes.
  • Pain and irritation in the affected eye.
  • Vision changes, such as blurred vision or inability to see.
  • Sensitivity to light.
  • Inability to open your eye
  • Eye discharge.
  • Excessive tearing.

Without treatment, keratitis symptoms will progress and get worse. When symptoms appear may depend on the type of keratitis. For example, symptoms of bacterial keratitis can appear immediately.


There are two main types of keratitis, depending on what causes it. Keratitis can be classified as infectious or non-infectious.

Infectious Keratitis

Infectious keratitis is caused by one of the following:

Bacteria: Pseudomonas aeruginosa and Staphylococcus aureus are the two most common types of bacteria that cause bacterial keratitis. It mainly develops in people who use contacts inappropriately.

Fungi – Fungal keratitis is caused by Aspergillus, Candida, or Fusarium. As with bacterial keratitis, fungal keratitis is more likely to affect contact lens wearers. However, it is also possible to be exposed to these fungi outdoors.

Parasites: An organism called Acanthamoeba has become more common in the United States in those who wear contact lenses.

The parasite lives outdoors and can be picked up by swimming in a lake, walking in a wooded area, or by getting water from your contact lenses. This type of infection is called Acanthamoeba keratitis.

Viruses: Viral keratitis is mainly caused by the herpes simplex virus, which progresses from conjunctivitis to keratitis.

Non-infectious keratitis

Possible non-infectious causes of keratitis include:

  • Injury to the eye, such as a scratch.
  • Wearing contact lenses too long.
  • Wear contact lenses while swimming.
  • Living in a hot climate, which increases the risk of plant materials damaging your cornea.
  • A weakened immune system.
  • Exposure to strong sunlight, called photo keratitis .


Keratitis can be transmitted through infection. This can happen if you come in contact with an infectious substance and then touch your eyes. It can also happen if you get sick and then the infection spreads to your eyes.

In some cases, you can even pass the keratitis yourself. For example, if you have an open herpes sore, touching it before touching the eye area can lead to this condition.

Non-infectious keratitis is not contagious. These cases only become contagious if an infection develops.


Any suspected symptoms of keratitis should be analyzed immediately. Your doctor can help you make a diagnosis so you can receive treatment before complications develop.

To diagnose keratitis, your doctor will first talk to you about the history of your symptoms and then look you in the eye. If your eye is closed from an infection, they will help you open it so they can perform a complete corneal exam.

A slit lamp or flashlight may be used during the exam. A slit lamp works by magnifying the structures inside your eye so your doctor can take a closer look at any damage caused by keratitis.

A flashlight is used to monitor your student for any unusual changes. A stain may be applied to the surface of the eye to help your doctor look for other changes.

To rule out infection, your doctor may order lab tests. They will collect a corneal or tear sample to identify the exact cause of the keratitis.

Your doctor can also test your vision with an eye chart.


Keratitis treatment depends on what is causing it. If you have an infection, you will need to take prescription medicine.

Your doctor may prescribe eye drops, oral medications, or both. These include:

  • Antibiotics for bacterial infections.
  • Biocides for parasitic infections.
  • Antifungals for fungal infections.
  • Antivirals for viral infections.

Not all forms of keratitis infections respond to medications in the same way. Acanthamoeba keratitis can sometimes be resistant to antibiotics, so your doctor may need to re-examine your eyes if the infection does not clear up.

Also, antiviral medications may not completely kill the virus that caused the keratitis; you will have to watch out for recurring infections as a result.

Non-infectious keratitis does not need medication. You will only need a prescription if your condition worsens and turns into an infection. An eye patch can help protect the affected area and stimulate the healing process.


When treated promptly, you are likely to recover from keratitis. However, complications can arise if it is not treated. Untreated keratitis can cause permanent vision damage.

Other possible complications include:

  • Cicatrices corneales.
  • Recurrent eye infections.
  • Chronic (long-term) inflammation.
  • Sores on the cornea, known as corneal ulcers.

In severe cases, you may need a procedure known as a corneal transplant . Your doctor will likely recommend this surgery if the keratitis causes vision damage or blindness.


While keratitis can happen to anyone, there are steps you can take to help prevent it from happening. This is especially true if you wear contact lenses. You can:

  • Do not sleep with contact lenses on.
  • Remove contact lenses before swimming.
  • Handle the contacts with clean hands.
  • Use the correct cleaning solution, never water or diluted solutions.
  • Replace your contacts regularly, as recommended by your doctor.

Preventing viral infections can also help lower the risk of keratitis. Be sure to wash your hands well before touching your eyes, especially if you think you have been exposed to a virus.