Acanthamoeba keratitis

What is it?

Acanthamoeba keratitis is a rare but serious eye infection that is painful and sight-threatening. It affects the clear front surface of the eye (the cornea) which becomes painful and swollen (inflamed).

Did you know?

  • Acanthamoeba is the name of a tiny form of life with only one cell.

  • Keratitis is the name for inflammation in the cornea.

  • Causes

    Acanthamoeba are usually found in soil and in water, for example in hot and cold tap water, swimming pools, hot tubs and sea water.

    In the UK, most people who get Acanthamoeba keratitis wear contact lenses. About 1 in 30,000 contact lens wearers become infected. It’s also possible to become infected after an injury to the cornea.

    Using tap water to clean or store contact lenses or having poor contact lens hygiene increases the risk of infection. Examples of poor lens hygiene are not using disinfection solutions properly, reusing the solution in the contact lens case, failing to empty and dry the contact lens case after use and storing lenses in water overnight.

    Wearing contact lenses when swimming or taking a shower also increases risk. So does putting lenses in with wet hands from tap water.

  • Symptoms

    Acanthamoeba keratitis is very painful for most people but it’s possible to have no pain at all. Other symptoms include red eyes that feel irritated or like they have something in them. Some people will get blurred or poor vision. Some people become sensitive to light and find it painful or uncomfortable.

  • Treatments

    Acanthamoeba keratitis needs immediate attention. Treatment is usually with antiseptic eye drops. It can be hard to treat and may also need antibiotics or steroids as well as painkillers.

    The most serious infections will mean the need for a corneal transplant. This involves surgery to remove the damaged cornea and replace it with a healthy one from a suitable donor.

  • Prevention

    Do make sure you have good contact lens hygiene. For example, clean and dry your hands well before touching your lenses. Take your lenses out before sleeping.

    Follow the advice from your optician and the manufacturer’s instructions for your lenses. Think about using daily disposable lenses instead of ones that need to be cleaned and stored to use again.

    Don’t wear contact lenses when you wash in the bath or shower, or when you go swimming at a pool or in the sea.

  • Research

    Current Acanthamoeba keratitis research is focussed on improving diagnosis and understanding why some people are more severely affected than others. We also need to find targets for drug treatment.

    Here are some of our latest stories on AK research:

    The Future of Research

    Fight for Sight funding PhD into rare eye infection that can affect contact lens wearers

  • Clinical trials

    You could play an important part in eye research by being a participant in clinical research study that may benefit many people. You could even help shape clinical research by becoming more actively involved and having a say. Patients, carer, or anyone with an interest can help.

    What are clinical trials

    Clinical trials are research studies that find out if a medical strategy, treatment, or device is safe and effective for humans. They are a key research tool for improving medical knowledge and patient care. The people who carry out research are mostly the same doctors and healthcare professionals who treat people. Their aim is to find better ways of treating patients and keeping people healthy.

    Taking part

    Here are some ways to find out about research projects and clinical trials that you can get involved in.

    UK Clinical Trials Gateway

    The UK Clinical Trials Gateway run by the National Institute for Health Research (NIHR) provides easy to understand information about clinical research trials running in the UK, and gives to a large range of information about these trials. It is designed to enable patients and clinicians to locate and contact trials of interest. Visit their website and select the eye condition that you are interested in.

    NIHR Clinical Research Network Portfolio

    The NIHR Clinical Research Network Portfolio is a database of high-quality clinical research studies in England, Northern Ireland, Scotland and Wales. Within this the Ophthalmology Specialty Group supports a national portfolio of research studies in ophthalmology and the vision sciences. See their website for details.

    If you wish to join a trial it is always best to discuss this with your doctor or clinical team first.

Last updated September 2015
Approved by Professor John Dart, Moorfields Eye Hospital and UCL Institute of Ophthalmology

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