Conjunctivitis
http://www.netdoctor.co.uk/conditions/eyes/a5325/conjunctivitis-inflammation-of-the-eye/
What is conjunctivitis?
Conjunctivitis is the term given to inflammation of the conjunctiva – the mucous membrane covering the white of the eyes and the inner side of the eyelids.
Conjunctivitis is a common eye condition, which is usually not serious, but can be uncomfortable and irritating.
Conjunctivitis commonly affects both eyes at the same time – although it may start in one eye and spread to the other after a day or two. It can be asymmetrical, affecting one eye more than the other.
Conjunctivitis can be caused by a variety of factors.
Treatment of it depends on the cause.
What causes conjunctivitis?
There are five different kinds of conjunctivitis, each with their own cause, symptoms and trearment.
Bacterial conjunctivitis
Cause
Bacterial conjunctivitis is an infection caused by bacteria, such asStaphylococci, Streptococci or Haemophilus. These organisms may come from the patient's own skin, upper respiratory tract or caught from another person with conjunctivitis.
Symptoms
Bacterial conjunctivitis affects both eyes. The eyes will usually feel gritty and irritated with a sticky discharge.
The eyelids may be stuck together, particularly in the mornings, and there may be discharge or crusting on the eyelashes.
Treatment
This type of conjunctivitis is usually treated with broad-spectrum antibiotic drops or ointment, eg chloramphenicol or fusidic acid.
The eyes should also be cleaned with cotton wool soaked in cooled boiled water to remove any crusts or stickiness.
Evidence shows that while 64 per cent of bacterial conjunctivitis cases will clear on their own within five days, antibiotic eye medication does lead to increased success rates and earlier remission.
Bacterial conjunctivitis does not usually affect a person's vision.
Viral conjunctivitis
Causes
Viral conjunctivitis can be caused by adenovirus and is often associated with the common cold.
This type of conjunctivitis can spread rapidly between people and may cause an epidemic.
People often feel unwell and 'under the weather' when they have viral conjunctivitis.
Symptoms
Viral conjunctivitis is characterised by red eyes and a watery discharge.
The eyelids and even the conjunctiva on the white of the eye may swell, creating a glassy appearance.
The eyes are uncomfortable, with patients usually describing a sensation of 'something in the eye'.
There may also be the generalised symptoms of a cold, including tender lymph nodes (swollen glands) around the ear or the neck.
This type of conjunctivitis may also spread to the cornea (keratitis) to cause hazy vision. It can persist for several weeks.
Treatment
Viral conjunctivitis cannot be cured, but the symptoms can treated to improve comfort.
A lubricant ointment, such as Carbomer can be used to make the eyes more comfortable.
Cold compresses on the eyes and tablets, such as paracetamol and ibuprofen, can also help ease symptoms.
As viral conjunctivitis is a highly contagious condition, it's important to ensure that a strict code of hygiene is adhered to, such as regular hand and face washing, and no sharing of face towels.
Close contact with other people, eg at school, is not recommended for the first one to two weeks to help prevent spread of the infection.
This condition may persist for a prolonged time and in some instances corticosteroid drops have been advocated, although these should only be given under the strict supervision of a doctor specialising in eye disease (such as an ophthalmologist).
Chlamydial conjunctivitis
Cause
This type of conjunctivitis is caused by an organism called Chlamydia trachomatis.
This organism may also affect other parts of the body and can cause the sexually transmitted infection, chlamydia.
Symptoms
Chlamydial conjunctivitis causes one or both eyes to be red with a sticky discharge and, sometimes, swollen eyelids.
Treatment
Chlamydial conjunctivitis is treated with antibiotic tablets to ensure that infection is eliminated, including any possible infection of the genitourinary tract.
Adults are usually prescribed tetracycline or macrolide antibiotics. Children cannot be treated with tetracycline tablets, so macrolides (eg azithromycin) is usually used for them.
Because of the possible infection of other body sites, any sexually transmitted infections should be identified and both the patient and their partners must be treated.
Allergic conjunctivitis
Cause
Allergic conjunctivitis is common in people who have other types of allergic disease, such as hay fever, asthma and eczema. Allergic conjunctivitis is often caused by antigens like pollen, dust mites or cosmetics.
Symptoms
Symptoms of allergic conjunctivitis include intense itching of the eyes, intermittent red eyes and stringy discharge.
These symptoms may occur at particular times of the year, such as spring and summer, when there is a lot of pollen in the air. Some people unfortunately can get allergic conjunctivitis all year round.
Treatment
Allergic conjunctivitis can be treated using antihistamine drops, such as sodium cromoglicate to prevent the body mounting an allergic response. These drops need to be used for weeks to give any result.
Corticosteroid drops are occasionally used to treat allergic conjunctivitis, but these can have serious side-effects and should only be used under the supervision of an ophthalmologist.
Lubricating/moisturising eye drops can also be used to soothe the surface of the eyes.
The main treatment for allergic conjunctivitis should be identifying what is triggering the allergic response and removing it.
Reactive conjunctivitis – chemical or irritant conjunctivitis
Some people are sensitive to chemicals in swimming pools or to smoke or fumes and this can cause an irritation of the conjunctiva with discomfort, redness and watering. In such cases, these irritants should be avoided.
Conjunctivitis in young children
Small children may be susceptible to infective conjunctivitis and they may develop severe forms of the condition because of poor immune defences.
Conjunctivitis in a newborn baby (up to 4 weeks of age) is called ophthalmia neonatorum.
This may be due to an infection that has been contracted during the passage through the mother's birth canal, such as sexually transmitted infections, including gonorrhoea and chlamydia.
Small babies may also develop conjunctivitis from other types of infection. Swabs should always be taken so that appropriate treatment can be given.
Watery eyes in babies
Small babies often have poorly developed tear drainage passages – a condition known as nasolacrimal duct obstruction.
These children are susceptible to watering eyes and they may intermittently become sticky.
This is usually not serious and most of the time it settles down without treatment by the age of one or two years.
What is Trachoma?
Trachoma is a form of conjunctivitis that is common in the developing world, particularly in parts of Africa and Asia.
It's exacerbated by a lack of clean water because it's spread by contact with other infected people and by flies.
Trachoma is one of the world's greatest causes of blindness because long-standing infection develops and causes scarring of the eyelids and eyes.
The most effective treatment is to provide a clean supply of water that allows good hygiene.
Simple antibiotics are also effective in treating the infection in the short term, but recurrent re-infection from within communities causes more damage.
How does the doctor make the diagnosis of conjunctivitis?
Conjunctivitis can usually be diagnosed and treated by your GP; a pharmacist may also be consulted for advice.
The doctor will usually diagnose the condition based on examination of your eyes and the history that you give.
Sometimes, a swab has to be taken from the eye – especially if there is no improvement on standard treatment.
In some cases that are severe or do not respond to treatment, you may need to see an eye specialist (ophthalmologist).
What should I pay particular attention to?
If there is any worsening of the symptoms despite treatment or if the vision deteriorates, a further consultation with your doctor should be requested even if treatment is being carried out.
If you wear contact lenses and develop symptoms of conjunctivitis, it's important to see your doctor. People who wear contact lenses can develop a serious infection of the cornea which requires specialist treatment.
What can be done to avoid conjunctivitis?
Hand washing is probably the most important preventative measure to take. There should also be no sharing of face towels, especially if someone has conjunctivitis.
Conjunctivitis can spread from one eye to the other, especially when you rub your eyes. Pus and crust should be removed by bathing the eye with lukewarm salt water, which can also lessen the symptoms.
Use disposable tissues when you dry the eyes and throw them away after use. This will limit the contamination.
Dispose of any antibiotic eye drops after the treatment is over.
It is sensible to never share eye make up or eye drops with another person.
How does conjunctivitis usually progress?
Even if left untreated, most cases of bacterial and viral conjunctivitis will gradually get better on their own in a few weeks. Allergic conjunctivitis usually continues while there's exposure to the aggravating agent.
With appropriate treatment, the eyes are usually more comfortable within a few days, although cases of adenoviral infection may cause problems for some weeks.
