Keratitis (also known as “corneal ulcer”) is an inflammation of the cornea – the clear, dome shaped window located at the front of the eye that covers the iris and pupil. Keratitis resulting from infections (called infectious keratitis) can be caused by bacteria, viruses, fungi, and parasites. Keratitis can also occur a result of other insults to the cornea (called noninfectious keratitis) such as an injury, wearing your contact lenses too long, or very dry eye. Keratitis can become serious quickly – see your eye doctor right away to prevent vision loss.
Keratitis can be infectious or non-infectious.
Bacterial infections: Bacterial keratitis is common in people who wear contact lenses. Bacteria can grow on your contact lenses or contact lens case if you do not clean and store them properly. The bacteria can also come from contaminated eye drops or contact lens solution. It is more likely to occur if you wear extended-wear contact lenses (contact lenses that you sleep in).
Viral infections: Keratitis from a viral infection is usually due to the herpes simplex virus, the chicken pox virus, or the common cold. If you’re sick, be careful about touching your eyes and keeping your hands clean. If you have a cold sore (the herpes simplex virus), you can spread it by touching your sore and then your eye. The virus that causes cold sores may cause repeated keratitis infections. The repeated infections are triggered by stress, an impaired immune system, or exposure to sunlight.
Fungal infections: This type of keratitis infection is not common. It can be caused by scratching your eye with a branch or plant material. It can also be caused by the improper use of contact lenses or steroid eye drops.
Parasitic (Acanthamoeba) infection:
Acanthamoeba Keratits: Lorenzo-Morales et al 2015 - 10.051/parasite/2015010
Acanthamoeba are microscopic, single-celled organisms called amoeba. They are the most common amoebae found in fresh water and soil. The two biggest risk factors to get an Acanthamoeba infection are poor contact lens hygiene and exposure to water (like swimming pools and hot tubs) while wearing contact lenses.
Acanthamoeba keratitis: Eddie314 at the English language Wikipedia
Injury: Scratches, scrapes and cuts to your cornea can cause noninfectious keratitis. These injuries can happen from a variety of sources, such as fingernail scratches, paper cuts, makeup brushes, tree branches, contact lenses, and chemical burns. The injury may also let in bacterial or fungus to cause an infectious keratitis.
Eyelid disorders that prevent proper eyelid function: If the eyelid does not close properly, the cornea can dry out, and keratitis can develop.
Dry eye syndrome: The eyes are not able to leave a protective layer of tears (called the tear film) that washes, soothes and protects the eye every time you blink. The eye then becomes dry and irritated which can lead to keratitis.
Exposure to intense ultraviolet (UV) light (photokeratitis): Photokeratitis is caused by damage to the cornea by UV light. It can be caused by the reflection of UV light from the sun from sand, water, ice and snow; looking directly at a solar eclipse without eye protection, tanning beds, and/or welding.
The first sign and symptoms of keratitis is usually eye pain, redness, and blurred vision. Your eye may burn or feel irritated, or it may feel like you have something in it.
Signs and symptoms of keratitis include:
Keratitis can cause permanent vision loss, so see your eye doctor right away if you have any of these symptoms.
Note: Conjunctivitis (also known as "pink eye") is an inflammation of the conjunctiva. This condition has similar symptoms and may be confused with keratitis. If you have the keratitis symptoms listed above, see your eye doctor right away. For more information on conjunctivitis, visit preventblindness.org/conjunctivitis-pink-eye.
You may be at increased risk for keratitis if you:
If you wear contact lenses: Safe handling, storage and cleaning of your contact lenses are key steps to reduce your risk of keratitis. It is important to learn how to take care of your contact lenses. For more information, visit: preventblindness.org/wearing-contact-lenses.
If you notice any of the signs or symptoms of keratitis, make an appointment to see your eye doctor right away. If you wear contact lenses, do not wear them until you find out what is wrong. Bring your contact lenses and contact lens case with you to the eye exam. Delays in diagnosis and treatment of keratitis can lead to serious complications, including blindness.
At your eye exam, the eye doctor will perform the following tests:
A very mild case of noninfectious keratitis will usually heal on its own. For mild cases, your eye doctor may recommend that you use artificial tear drops. If your case is more severe and includes tearing and pain, you may need to use antibiotic eye drops to help with symptoms and prevent infection. For information on how to properly take eye drop medications, visit: preventblindness.org/taking-eye-drop-medications.
Treatment of infectious keratitis varies, depending on the cause of the infection.
Your eye doctor may also prescribe steroid eye drops (never with fungal keratitis) after your infection has improved or is gone. These drops help to reduce swelling and help prevent scarring. You should only use steroid eye drops under close supervision by your eye doctor because steroid eye drops can sometimes make an infection worse.
A corneal transplant replaces a damaged cornea with a healthy donor cornea. You may require a corneal transplant if you have the following:
Keratitis, if caught early, is usually easy to treat and clears up quickly. Corneal scarring is the most common complication of keratitis, which can lead to vision loss. If keratitis is not treated in a timely manner, the infection could go through the cornea and spread to other areas of the eye leading to possible blindness. It is important to see any eye doctor as soon as symptoms of keratitis are noticed.
If you are sick, wash your hands often and try not to touch your eyes. Wear proper eye protection if you are looking at intense UV light. And if you wear contact lenses, handle and care for them correctly:
Prevent Blindness has a list of financial assistance resources for those in need of support in meeting their eye health needs and medications. Visit: preventblindness.org/visioncare-financial-assistance-information.