Keratoconjunctivitis

Overview

What is keratoconjunctivitis?

Keratoconjunctivitis is the term for an eye condition that involves inflammation of both your cornea and conjunctiva at the same time.

You have a cornea — a clear window — on the front of each eye. Your cornea is made of tough, transparent tissue. It covers your iris and your pupil. Inflammation of your cornea is called keratitis.

Your conjunctiva is a clear, thin tissue that covers your sclera (the white part of your eyes) and also lines the inside of your eyelids. Inflammation of your conjunctiva is called pink eye (conjunctivitis).

The difference between having only keratitis or only conjunctivitis is with keratoconjunctivitis, you have both.

What are the types of keratoconjunctivitis?

Generally, there are several ways to divide keratoconjunctivitis into types or forms. For instance, you can have it in one eye (unilateral) or in both eyes (bilateral).

It can be hyperacute (last less than one week), acute (lasting three to four weeks) or chronic (lasting for more than four weeks).

Keratoconjunctivitis can be infectious or non-infectious. Non-infectious causes include allergies, autoimmune disorders or toxins.

What's the difference between keratoconjunctivitis and xerophthalmia?

Keratoconjunctivitis and xerophthalmia both affect the same parts of your eye — your cornea and your conjunctiva. They both involve inflammation too. However, vitamin A deficiency causes xerophthalmia and the dry eyes related to the condition.

How common is keratoconjunctivitis?

An estimated 6 million people in the U.S. go to their healthcare provider with signs of keratoconjunctivitis or conjunctivitis each year. These conditions can happen to anyone, but different types of keratoconjunctivitis are more common among certain groups. For instance, bacterial keratoconjunctivitis is more common among school-age children.

Symptoms and Causes

What are the signs and symptoms of keratoconjunctivitis?

The signs and symptoms of keratoconjunctivitis may include:

  • Itchy eyes, discomfort or a feeling that something is in your eyes.
  • Watery eyes.
  • Swollen eyelids (blepharitis).
  • Sensitivity to light.
  • Discharge from your eyes.
  • Blurry vision that may come and go.

What causes keratoconjunctivitis?

There are many things that can cause keratoconjunctivitis, and some of them are contagious. Others are non-infectious. The type of keratoconjunctivitis you have corresponds to what’s causing it.

Non-infectious keratoconjunctivitis

There are forms of keratoconjunctivitis that aren’t associated with contagious illness. These include:

  • Allergic keratoconjunctivitis: This is a very common form. People who are allergic to dust, pollen or animal dander may find their eyes getting swollen and watery. Vernal keratoconjunctivitis is a severe form of allergic keratoconjunctivitis that usually affects children. Another form is atopic keratoconjunctivitis. It can happen in people who have eczema, which is also known as atopic dermatitis. It’s related to atopy, a genetic condition that makes you more vulnerable to developing allergies.
  • Exposure keratoconjunctivitis: This form can happen when the surface of your eye isn’t protected adequately, such as when your eyes don’t close completely.
  • Neurotropic keratoconjunctivitis: This rare form of keratoconjunctivitis involves corneal nerves that don’t work the way they should. There are non-infectious causes or things that increase your risk. These include eye injury, surgery, tumors, diabetes and multiple sclerosis. There are other infectious causes or risk factors that include herpes simplex and herpes zoster infections.
  • Keratoconjunctivitis sicca: This condition is also called dry eye disease and happens in both eyes. If you have it, your eyes can’t produce enough tears or the tears don’t have the right combination of ingredients to keep them from evaporating quickly. Dry eyes happen with Sjögren's syndrome and may be associated with other types of autoimmune disorders.
  • Superior limbic keratoconjunctivitis: The cause of this form isn’t known, but it’s not contagious. One theory is that it comes from constant friction in your eye. It often happens around age 60 and is more common in women and people assigned female at birth than in men and people assigned male at birth. It may be associated with thyroid disease. Another disorder called contact lens-induced superior limbic keratoconjunctivitis can affect people who wear soft contact lenses and use a certain kind of contact lens solution.

Infectious keratoconjunctivitis

This type includes bacterial, viral and fungal forms. Some of these forms include:

  • Epidemic keratoconjunctivitis: This form is caused by an adenovirus and may also be called adenoviral keratoconjunctivitis. The adenovirus, which can be found nearly everywhere, attacks your eyes, respiratory tract, gastrointestinal system and genitourinary system.
  • Bacterial keratoconjunctivitis: This form can be caused by many kinds of bacteria. It’s very contagious and often found among children.
  • Herpetic keratoconjunctivitis: This form is caused by herpes virus infections.
  • Phlyctenular keratoconjunctivitis: This form is described as a hypersensitivity reaction to germs, such as Staphylococcus aureus, or to the germ that causes tuberculosis. In phlyctenular keratoconjunctivitis, bumps called phylctenules can form in your eyes.
  • Chlamydial keratoconjunctivitis: This sexually transmitted infection happens when you touch your eyes after touching infected genital fluids.
  • Microsporidial keratoconjunctivitis: This type is caused by fungi and was originally found most often in people with HIV/AIDS. Now it can be found in otherwise healthy people.

Diagnosis and Tests

How is keratoconjunctivitis diagnosed?

Your healthcare provider will start almost any discussion reviewing your symptoms and medical history. They’ll ask you about other conditions, recent illnesses and things like whether or not you wear contact lenses. Your provider may also perform:

  • An eye exam using slit lamp equipment, with or without a fluorescein eye stain test. This eye stain calls for putting dye-containing drops into your eye to highlight any issues.
  • Cell culture and immunoassay tests on the discharge from your eyes to find the infectious agent.
  • Lacrimal function tests to determine how well your eyes do at creating tears. The Schirmer test uses moisture produced over five minutes on a piece of filter paper at the edge of your eye.
  • Tests to measure how sensitive your cornea is.
  • Tests that take images of your eyes.

Management and Treatment

How is keratoconjunctivitis treated?

Treating keratoconjunctivitis depends on what’s causing the condition. In general, your healthcare provider may suggest:

  • Using eye drops. These could be just artificial tears to moisten your eyes in the case of allergic keratoconjunctivitis. It may be antibiotic or antifungal drops for infectious types. They may recommend corticosteroid drops in other cases related to immune system issues. You may need more than one type of medication.
  • Using a lubricating ointment when you’re sleeping.
  • Using other topical or oral products that contain antihistamines or mast cell stabilizers.
  • Putting cold compresses over your eyes to ease symptoms.
  • Doing eyelid scrubs if you have blepharitis.

Treating very dry eyes if you have keratoconjunctivitis sicca may include:

  • Putting a plug in the punctum (the small holes in the corners of your eyes) to keep tears in your eyes.
  • Sewing eyelids together incompletely to keep moisture in.
  • Using an electrical probe inserted in your nose to produce tears. This could be done several times a day.

Your provider may suggest surgery to treat resistant forms of some types of keratoconjunctivitis.

If you have keratoconjunctivitis that’s related to other conditions, your provider will treat the other illnesses.

Prevention

How can I reduce my risk of developing keratoconjunctivitis?

If you have other conditions that are associated with keratoconjunctivitis, you can reduce your risk by following your treatment plan for those conditions. For instance, you can:

  • Take allergy medications to reduce your risk of itchy, uncomfortable eyes.
  • Make sure you follow your eye care provider’s recommendations about safely wearing contact lenses by washing your hands when you put lenses in your eyes, using clean lenses and changing them when you need to.
  • Control your blood sugar levels if you have diabetes.
  • Avoid known allergens whenever you can.
  • Wash your hands often.
  • Avoid rubbing or touching your eyes.
  • Wearing sunglasses when the sun is bright and weather is dry.

Outlook / Prognosis

What can I expect if I have keratoconjunctivitis?

Some types of keratoconjunctivitis are long-term (chronic) conditions. You’ll probably be managing them on a regular basis. Others, like those caused by infections, may clear up quickly with treatment.

Forms of allergic keratoconjunctivitis (vernal and atopic) can cause eye damage if you don’t get treatment.

Living With

When should I see my healthcare provider about keratoconjunctivitis?

See your healthcare or eye care provider if you have persistent redness and discomfort in your eye, especially if your vision is blurred or you have discharge.

A note from Cleveland Clinic

If your eyes are puffy, watery, itchy and red where they should be white, you should contact your healthcare provider. You may have keratoconjunctivitis, or inflammation in both your cornea and your conjunctiva. While some forms may resolve on their own, other types may need to be treated by your healthcare provider.

Last reviewed by a Cleveland Clinic medical professional on 07/08/2022.

References

  • American Academy of Ophthalmology. Multiple pages reviewed for this article. Epidemic Keratoconjunctivitis. (https://eyewiki.aao.org/Epidemic_Keratoconjunctivitis) Accessed 8/1/2022.
  • Burrow MK, Patel BC. Keratoconjunctivitis. (https://www.ncbi.nlm.nih.gov/books/NBK542279/) [Updated 2021 Nov 2]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Accessed 8/1/2022.
  • Merck Manuals. Multiple pages reviewed for this article. Phlyctenular Keratonoconjunctivitis. (https://www.merckmanuals.com/professional/eye-disorders/corneal-disorders/phlyctenular-keratoconjunctivitis?query=keratoconjunctivitis) Accessed 8/1/2022.

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