Acanthamoeba Keratitis
Acanthamoeba keratitis is a rare eye infection that can lead to a permanent loss of vision. The condition is caused by Acanthamoeba, a tiny organism commonly found in water sources such as lakes, oceans and tap water, as well as in the soil and air conditioning and sewage systems. If a person swims in a body of water contaminated by Acanthamoeba, for example, the microbe may come into contact with the cornea of the eye and initiate an infection.
Acanthamoeba keratitis usually occurs in otherwise healthy individuals. Contact lens wearers, however, are often at a higher risk of infection because the microbes can settle on the surface of a lens.
Symptoms of Acanthamoeba Keratitis
The typical symptoms of Acanthamoeba keratitis may initially be mistaken for those of several other, less serious eye conditions, as many types of infections produce similar reactions. Therefore, it is important to visit an eye doctor for a thorough examination and diagnosis. The symptoms of Acanthamoeba keratitis can last for several days or persist for weeks, and if left untreated may result in permanent damage.
Common symptoms of the condition include:
- Eye pain
- Blurred vision
- Blepharospasm, or excessive eye blinking and spasms of the eye muscles
- Eye redness
- Photophobia, or a sensitivity to bright light
- Excessive tearing
- Sensation of a foreign substance in the eye
- Severe headaches
Risks for Acanthamoeba Keratitis
Anyone can develop Acanthamoeba keratitis, but it most frequently occurs in people who regularly wear contact lenses. Some common risk factors for Acanthamoeba keratitis may include:
- Improper storage and handling of contact lenses
- Hot tub use, swimming or showering while wearing contact lenses
- A history of trauma to the cornea
- Exposure to contaminated water
- Improper disinfection of contact lenses
Diagnosis of Acanthamoeba Keratitis
Acanthamoeba keratitis progresses rapidly, so early diagnosis is essential for preventing damage from occurring. The infection can usually be diagnosed based on the patient's symptoms, although for confirmation the doctor will typically also perform a confocal microscopy. This is an optical imaging technique that is used to magnify the area and provide a better view of the amoeba. Once the diagnosis is established, the doctor will determine an individualized treatment plan based on the patient's specific needs.
Treatment of Acanthamoeba Keratitis
Acanthamoeba keratitis is usually treated with prescription medications. These medications can alleviate symptoms and cure the infection, and typically begin to provide effective relief within a few weeks of use. However, once a patient has suffered from Acanthamoeba keratitis, there remains a greater risk for experiencing a recurrence of the condition in the future.
If the condition continues to progress or recurs despite the use of prescription medications, corneal surgery may be necessary. Surgery is generally only required when Acanthamoeba keratitis has been diagnosed at a later stage and only in those cases in which corneal scarring has occurred and vision is affected. One surgical option is a corneal transplantation, which involves the replacement of a damaged cornea, either partially or completely, with donated corneal tissue. Another surgical treatment method is phototherapeutic keratectomy, or PTK, during which a laser is used to remove damaged tissue from the cornea.
Prevention of Acanthamoeba Keratitis
Due to the complexities of Acanthamoeba keratitis and how quickly it can progress, preventative measures can significantly reduce a patient's risk for infection and corneal damage. Common methods of preventing this condition include visiting an eye care provider on a regular basis for examinations, removing contact lenses before entering a hot tub or going swimming, washing hands with soap and water before handling contact lenses and always properly cleaning and storing the lenses.