Keratoconjunctivitis: Symptoms, Types, and Causes

Redness, itching, and a gritty sensation in the eye can be signs of inflammation of the conjunctiva—the clear membrane that lines the eyelids and covers the white of the eye. In keratoconjunctivitis, the cornea, the clear outer part of the eye, is also involved. Below is a calm breakdown of which types of this condition exist, how each one manifests, and when it is time to see a doctor.

What keratoconjunctivitis is

The conjunctiva is a clear layer of tissue that lines the eyelids and covers the white of the eye. Conjunctivitis begins when this membrane swells and becomes inflamed, and in keratoconjunctivitis the cornea—the clear outer part of the eye through which we see—is also involved. Doctors name several causes of conjunctival inflammation: infection, an irritant, dry eyes, and allergy.

Tears protect the eye: they wash away microbes and irritants, and the proteins and antibodies they contain kill microbes. If the eyes are dry, it is easier for microbes and irritants to cause harm. Most often, inflammation is caused by viruses and bacteria, and "pink eye" usually refers to the viral form, which spreads easily among children. Irritants include chemicals, smoke, and dust; wearing contact lenses for a long time can also lead to inflammation.

Symptoms of keratoconjunctivitis

Inflammation usually affects both eyes. They become red, start to burn or feel as if sand has gotten into them, itching and tearing appear, and pus may accumulate and stick the eyelashes together. Other signs include blurred vision, crusts on the eyelids after a night's sleep (more often with a bacterial cause), eye pain, and photophobia.

Contagiousness depends on the cause. The form with sticky pus is contagious; if the eyes are red and there is a gritty sensation, the inflammation is usually contagious as well. The allergic form, for example with hay fever, causes red and watery eyes but is not transmitted to other people. Most often, the condition resolves within a couple of weeks even without treatment.

Viral keratoconjunctivitis

The viral form is highly contagious and spreads easily among children. It can pass through entire families and school classes, although full recovery is expected. Sometimes eye inflammation appears in a person with coronavirus infection before other typical symptoms. A test performed right in the doctor's office can sometimes identify the specific type of virus.

Newborns require special attention: in them, an eye infection may be caused by bacteria from the birth canal, and help is needed immediately to preserve vision.

Allergic keratoconjunctivitis

Allergic keratoconjunctivitis occurs when the membrane of the eye becomes inflamed in response to pollen, animal dander, mold, or another substance that causes allergy. The eyes become red and watery, and itching is felt, but this is not contagious to others. The long-term allergic form occurs in people with chronic allergy or asthma; this form is called vernal conjunctivitis, and it is more common in young men and boys during the spring and summer months. A similar condition is seen in those who have worn contact lenses for many years, and it can make further lens wear difficult.

How keratoconjunctivitis is diagnosed

The doctor examines the eyes and, if necessary, takes a swab from the conjunctiva—a sample for laboratory analysis. There are also tests that are sometimes performed right in the office to identify the specific type of virus and understand the cause of the inflammation.

When to see an ophthalmologist

Redness of the eye by itself is not a reason to call an ambulance. The numbers 103 and 112 are for cases when the condition has sharply worsened and the person needs emergency care.

You should see a doctor urgently if:

• a child under 30 days old has red eyes with sticky discharge—an urgent appointment is needed;
• the eye hurts;
• photophobia has appeared or vision has changed, for example wavy lines and flashes have occurred;
• the eyes are very red—one or both.

A routine visit to the doctor is needed if an infant has red eyes with sticky discharge; if you wear contact lenses and spots have appeared on the eyelids along with signs of inflammation—an allergy to the lenses is possible; if the eyelids or the skin around the eyes have become swollen and red and a headache has been added; if symptoms persist for more than a few days.

This material is for reference: it explains by which signs keratoconjunctivitis is recognized and which types exist, but it does not replace a consultation with a doctor who will examine the eye and identify the cause.

This content is for reference and does not replace a doctor's consultation. Medical disclaimer