What are the other Names for this Condition? (Also known as/Synonyms)

• Acanthamoeba Infection of Cornea
• Corneal Infection by Acanthamoeba

What is Acanthamoeba Keratitis? (Definition/Background Information)

• Acanthamoeba infection is caused by a single-celled organism that generally does not harm humans. However, when infection does occur, it can result in severe damage to various parts of the body
• The organism is found in natural environments all around the world and is highly-prevalent in water sources such as lakes, rivers, swimming pools, drinking water systems, and air-conditioning systems. It is also found in soil and dust
• Acanthamoeba Keratitis is a painful infection of the cornea (the transparent layer forming the front of the eye), caused by the amoeba entering the eye, usually through contact lens. It can cause blurry vision and light sensitivity
• If left undiagnosed or untreated, Acanthamoeba Keratitis may result in lifelong visual impairment or irreversible blindness. However, the infection responds well to early treatment

Who gets Acanthamoeba Keratitis? (Age and Sex Distribution)

• Individuals who wear contact lenses are at a high risk for Acanthamoeba Keratitis. However, it is a very uncommon condition
• Both males and females may be affected
• Worldwide, individuals of all races and ethnicity are prone to developing the condition

What are the Risk Factors for Acanthamoeba Keratitis? (Predisposing Factors)

The risk factors for Acanthamoeba Keratitis may include:

• Improper use, storage, and disinfection of contact lenses
• Exposure to contaminated water, which may come about through swimming pools, hot tubs, showers, or tap water, especially while wearing contact lenses
• Injury to the cornea (eye)
• Individuals with weak immune systems; although, it is important to note that Acanthamoeba Keratitis can develop in those with healthy immune systems too

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Acanthamoeba Keratitis? (Etiology)

• Acanthamoeba may gain entry to the body through the eyes and causes corneal inflammation (or keratitis) leading to Acanthamoeba Keratitis. The most common species responsible for infection are Acanthamoeba castellanii and Acanthamoeba polyphaga
• The risk for infection may increase through wearing infected lenses, improper handling/storing of contact lenses, wearing lens while using community swimming pools or through exposure to contaminated water
• A trauma to the cornea (corneal injury) followed by exposure to contaminated water may also result in Acanthamoeba Keratitis

Acanthamoeba infection has not been reported to spread from one individual to another through contact.

What are the Signs and Symptoms of Acanthamoeba Keratitis?

During the initial stages of infection, there may not be any significant signs and symptoms noted. The signs and symptoms of Acanthamoeba Keratitis during the later stages may include:

• Eye pain, redness, and excessive tearing
• Blurred vision
• Sensitivity to light
• Sensation of something in the eye

How is Acanthamoeba Keratitis Diagnosed?

Acanthamoeba Keratitis may be diagnosed by the following observations and tests. Generally, it is reported that a diagnosis of the condition may be challenging.

• Physical examination and medical history evaluation (including history of contact lens wear)
• Assessment of signs and symptoms
• General eye exam
• Observing Acanthamoeba cysts through confocal microscopy, a non-invasive optical imaging technique
• Culture of corneal scrapings to determine presence of the amoeba
• Slit-lamp examination

A differential diagnosis to eliminate other conditions/infections may be considered, before arriving at a definitive diagnosis. These may include:

• Contact lens associated keratitis
• Herpes simplex keratitis
• Staphylococcal marginal keratitis
• Other forms of infectious keratitis
• Sterile keratitis
• Recurrent corneal erosion

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Acanthamoeba Keratitis?

The complications of Acanthamoeba Keratitis may include:

• Perforation of the cornea
• Progression into more severe eye disease resulting in severe scarring of the eye, if left untreated or if treatment fails
• Permanent blindness
• Complications from treatment of the infection
• Decreased quality of life

How is Acanthamoeba Keratitis Treated?

The treatment for Acanthamoeba Keratitis is difficult; also, the treatment regimens are not well established. Following are some general treatment methods:

• Medical therapy using combination drugs (prescription medications)
• Use of topical applications and antiseptic eye drops
• Corneal transplant may be necessary if there is corneal perforation. However, surgery is usually postponed until the eye is free of infection

The treatment can last anywhere from 3 months to more than a year.

How can Acanthamoeba Keratitis be Prevented?

The following are some guidelines for possible prevention of Acanthamoeba Keratitis:

• Clean and replace lenses according to the instructions of the eye care provider
• Remove lenses before any activity involving contact with water
• Store reusable lenses in the proper storage container; replace storage cases in a timely manner
• Wash hands with soap and water before touching one’s eyes
• Have regular eye examinations
• Seek treatment for underlying medical conditions that may reduce immunity
• In general, follow good hygiene practices

What is the Prognosis of Acanthamoeba Keratitis? (Outcomes/Resolutions)

• The prognosis for Acanthamoeba Keratitis is mostly good, since the condition is treatable with an early diagnosis and prompt treatment (which is extremely important)
• However, a delayed diagnosis and/or treatment may adversely affect outcomes. In some cases, this may result in irreversible damage to the eye or even complete blindness

Additional and Relevant Useful Information for Acanthamoeba Keratitis:

Please visit our Eye & Vision Health Center for more physician-approved health information:

https://www.dovemed.com/health-topics/vision-center/