Acanthamoeba Keratitis

Learn more about Acanthamoeba Keratitis, including The Symptoms, The Causes, and The Treatments.

The information below is not intended for self diagnose of an eye condition. If you are worried or suffering from an eye problem, please call us on 0208 524 2887 and book in to see us.

Bhavita Magudia
Acanthamoeba Keratitis - Explained
February 3, 2019
Back to Common Eye Conditions

What Is Acanthamoeba Keratitis

Acanthamoeba keratitis (AK) is an infection in the cornea; the cornea is the clear layer that covers the iris (coloured part of your eye). A microorganism called acanthamoeba causes the infection and it is not a bacterial infection. Acanthamoeba keratitis has two cycles active and dormant.

To detect acanthamoeba keratitis your eye will be examined using a slit lamp, to assess for inflammation and typical clinical signs of the infection. A scrape & culture or swab of the cornea would be taken for further analysis at the eye hospital to diagnose acanthamoeba keratitis. A variety of tests, analysis of your symptoms and signs are used to diagnose acanthamoeba keratitis to differentiate it from other eye infections.

Acanthamoeba Keratitis - Symptoms

• Pain – can be severe

• Red eyes or eye

• Light sensitivity – the cornea can become cloudy and cause more light scatter.

• Reduced or poorer vision, which is caused by the inflammation of the cornea. Inflammation may lead to scarring of the cornea.

• Watery eyes

Acanthamoeba Keratitis - Causes

Acanthamoeba are found in water, tap water, swimming pools, hot tubs, soil and air. Handling of contact lenses with unwashed or wet hands, poor contact lens hygiene can also cause acanthamoeba keratitis. Acanthamoeba keratitis is more common in contact lens wearers and can also occur with patients who have a corneal abrasion or injury.

Acanthamoeba Keratitis - Treatments

Antiseptic eye drops such as PHMB, Chlorhexidine, Brolene, Hexamidine are usually prescribed. These would be used hourly (including overnight) for the first few days. Thereafter it would reduce to 2 hourly through the day and tapered off accordingly.

Anti-inflammatories and painkillers can also be prescribed for pain relief.

Dilating eye drops can also be prescribed to stop painful iris spasms.

Antibiotic eye drops - can be given to guard against bacterial infection or to treat an ongoing bacterial infection if present at the same time as acanthamoeba keratitis.

Steroids may be prescribed if there is severe inflammation or if you already have a preexisting inflammatory eye disease.

Treatment is always tailored to the individual. The duration of treatment is dependent on how quickly you have been diagnosed and have been administered the correct treatment. Duration of treatment can last up to 3-6 months or longer.

Possible side effects of acanthamoeba keratitis are:

Fixed dilated pupil

Damage to the iris

Blood vessel growth in the cornea

Secondary bacterial infection

Corneal transplant


If you are recovering from acanthamoeba keratitis, attend all your eye appointments. If you feel your symptoms are getting worse, if you lose or spill your eye drops contact the hospital eye service immediately.

Use an alarm clock on your smart phone to remind you when to use your drops.

Keep your eye drops in the fridge or as recommended. If you are out and about you can keep your eye drops cool by wrapping them in an ice pack.

Avoid getting water in your eyes when recovering from acanthamoeba keratitis

Avoid swimming, sauna and steam rooms when recovering from acanthamoeba keratitis

Avoid eye makeup until the infection is resolved

Avoid contact lens wear until advised otherwise. If you do resume contact lens wear move to a daily disposable contact lenses if available in your prescription.

Always wash and dry your hands thoroughly before touching your eyes

Notify the DVLA if your treatment is ongoing

If you are light sensitive, use a hat and good quality sunglasses. Polarised sunglasses are particular good for reducing unwanted glare; Maui Jim