Conjunctivitis

What is conjunctivitis?

Conjunctivitis, also known as "red eye" or "pink eye" is inflammation of the conjunctiva, the thin, transparent membrane that lines your eyelid and eyeball. There are several types of conjunctivitis, each with different causes. Conjunctivitis usually clears up without treatment, but if your symptoms are prolonged or severe, you may need medication. Conjunctivitis can affect one or both eyes. 

What causes conjunctivitis?

Conjunctivitis occurs when something irritates your conjunctiva leading to inflammation. It can be caused by a viral or bacterial infection, allergies, a foreign body in the eye, or an irritant such as a chemical or noxious substance.

There are three main types of conjunctivitis:

Infectious conjunctivitis

This type of conjunctivitis is caused by infection with a virus or bacteria. Infectious conjunctivitis is highly contagious and can spread easily to other people from direct contact or touching contaminated objects.

Viral conjunctivitis is the most common type of conjunctivitis. It is commonly caused by the same cold viruses that cause symptoms such as sore throat, runny nose and fever. Bacterial conjunctivitis can be caused by many types of bacteria including staph and strep.

Allergic conjunctivitis

Allergic conjunctivitis is caused by an allergic reaction to a substance such as pollen, cigarette smoke, animal dander, or dust mites. This type of conjunctivitis is not contagious.

Irritant conjunctivitis

This type of conjunctivitis occurs when something irritates your eye like contact lenses, a loose eyelash, air pollution, chlorine or exposure to certain chemicals. Irritant conjunctivitis is not contagious. 

Is conjunctivitis contagious?

Bacterial and viral conjunctivitis are contagious and can easily spread to your other eye or other people. It is spread by direct contact with a person who has conjunctivitis, either by touching them, or something they have touched. Infectious conjunctivitis is spread through the fluid (pus) that drains from your eye.

You can spread infectious conjunctivitis by:

• Direct contact, such as touching, hand-holding or shaking hands
• Touching contaminated objects and surfaces and touching your eyes before washing your hands
• Droplets from the air when an infected person coughs or sneezes

What are the symptoms of conjunctivitis?

Conjunctivitis can affect one or both eyes and may have a range of symptoms including:

• Redness
• Itching
• Burning
• Watery eyes
• A gritty feeling in your eyes
• Sticky discharge (pus) that sticks to your eyelashes and forms crusts during the night
• Sensitivity to light (photophobia)

When to see a consultant for conjunctivitis

Most cases of conjunctivitis clear up without treatment within a week or two, or with self-care and over-the-counter medication. If your conjunctivitis symptoms are severe, getting worse or not getting better, you may need medical treatment.

Make an appointment with your consultant if:

• You have symptoms of conjunctivitis that have not cleared up within seven days
• Your symptoms are severe or are accompanied by other symptoms such as eye pain, blurred vision or changes to your vision
• You wear contact lenses and have had symptoms of conjunctivitis for more than 24 hours (do not wear your contact lenses while you have conjunctivitis symptoms)
• You have spots on your eyelids as well as symptoms of conjunctivitis and wear contact lenses — this may indicate an allergy to your contact lenses
• You have a baby with symptoms of conjunctivitis (red, sticky eyes). See your consultant urgently if your baby is less than a month old.
• You have a weakened immune system due to medication or disease

How is conjunctivitis diagnosed?

Your consultant can usually diagnose conjunctivitis by asking about your symptoms and examining your eyes.

If your symptoms are severe, or your consultant suspects a more serious eye problem, they may order further tests or take a swab of the discharge from your eye to send to the laboratory for analysis.

How is conjunctivitis treated?

Conjunctivitis normally clears up on its own within one to two weeks. You can usually treat your symptoms yourself, but in some cases, you may need medication to treat your conjunctivitis.

Home care for conjunctivitis

Some things you can do at home to help ease symptoms of conjunctivitis include:

• Gently wipe your eyelids with cooled, boiled water and a clean cotton pad to remove the crusts. Use a separate cotton pad for each eye.
• Place a cold flannel on your eyelids for a few minutes a few times a day
• Do not wear your contact lenses until your conjunctivitis has cleared up

Medications for conjunctivitis

Medications for conjunctivitis include over-the-counter and prescription medications.

Your pharmacist can recommend over-the-counter medications to help relieve your symptoms.

Depending on the type of conjunctivitis you have, your consultant may prescribe medication to treat the infection, reduce inflammation, or manage your allergies.

Medications for conjunctivitis include:

Artificial tears

Artificial tears are lubricating eye drops that can help relieve the dryness associated with all types of conjunctivitis. They may also help wash out the allergens that cause allergic conjunctivitis

Antihistamines

Antihistamines work by blocking the action of histamine, a chemical produced by your body in response to an allergen such as pollen, pet dander, dust or mould. Antihistamines can help relieve symptoms of allergic conjunctivitis such as inflammation, itching, and discomfort. They can be bought over the counter as tablets or eye drops.

Antibiotics

Antibiotics work by stopping bacteria from reproducing inside your body. They are only available with a prescription. Bacterial conjunctivitis may need to be treated with antibiotic eyedrops or ointment.

Topical corticosteroids

If your conjunctivitis is severe and debilitating, your consultant may prescribe corticosteroid eye drops to reduce inflammation. Topical corticosteroids should only be used as a short-term treatment as they can cause serious side effects, including blurred vision, ocular hypertension and cataracts.

Non-steroidal anti-inflammatory drugs (NSAIDs)

Your consultant may recommend non-steroidal anti-inflammatory eye drops to reduce the redness and swelling associated with conjunctivitis. They may also help to relieve itching.

Mast-cell stabilisers

This medication, given in the form of eye drops, can be used as a long-term preventative treatment for allergic conjunctivitis. It works by preventing your body from releasing histamine during an allergic reaction.

Can conjunctivitis be prevented?

You can't always prevent conjunctivitis, but there are some things you can do to reduce your risk, including:

• Practice good hand hygiene by washing your hands frequently with warm soapy water
• Avoid rubbing or touching your eyes
• Don't share items such as towels, facecloths and pillows
• Wash towels, pillowcases and facecloths with laundry detergent on a hot cycle (above 50C)
• Cover your mouth and nose when sneezing and put the used tissues in the bin
• Limit exposure to known allergens where possible
• Don't wear eye makeup when you have conjunctivitis
• Replace your eye makeup if you have infectious conjunctivitis
• Never share eye makeup with others
• If you wear contact lenses, follow the manufacturer's instructions on cleaning or replacing them carefully

Getting treatment

Conjunctivitis is a common eye condition that causes red, itchy, watery eyes and a sticky discharge. It isn't usually serious, but symptoms can be uncomfortable. Most conjunctivitis goes away without treatment within one to two weeks, but in some cases, medication may be necessary.