Acanthamoeba keratitis

Definition

Acanthamoeba keratitis is a serious eye infection caused by a free-living, opportunistic protozoan parasite known as Acanthamoeba. It primarily affects the cornea, the clear, dome-shaped front part of the eye, and can lead to severe vision impairment or blindness if left untreated.

5 Must Know Facts For Your Next Test

1. Acanthamoeba keratitis is primarily associated with the use of contact lenses, especially improper lens hygiene and storage.
2. The infection can cause severe pain, redness, sensitivity to light, and vision loss if not treated promptly and effectively.
3. Acanthamoeba can form cyst-like structures that are resistant to many disinfectants, making the infection difficult to eradicate.
4. Risk factors for Acanthamoeba keratitis include swimming or bathing while wearing contact lenses, exposure to contaminated water, and a weakened immune system.
5. Treatment for Acanthamoeba keratitis typically involves a combination of anti-amoebic medications, such as polyhexamethylene biguanide (PHMB) or chlorhexidine, along with corticosteroids to reduce inflammation.

Review Questions

• Describe the key features of Acanthamoeba keratitis and explain how it is typically contracted.
  • Acanthamoeba keratitis is a serious eye infection caused by the free-living protozoan parasite Acanthamoeba. It primarily affects the cornea, the clear, dome-shaped front part of the eye, and can lead to severe vision impairment or blindness if left untreated. The infection is most commonly associated with the use of contact lenses, especially improper lens hygiene and storage. Risk factors include swimming or bathing while wearing contact lenses, exposure to contaminated water, and a weakened immune system.
• Explain the challenges in treating Acanthamoeba keratitis and describe the typical treatment approach.
  • Acanthamoeba keratitis can be difficult to treat due to the parasite's ability to form cyst-like structures that are resistant to many disinfectants. The typical treatment approach involves a combination of anti-amoebic medications, such as polyhexamethylene biguanide (PHMB) or chlorhexidine, along with corticosteroids to reduce inflammation. This combination therapy aims to eliminate the active trophozoite (feeding) stage of the parasite and disrupt the cyst-like structures, while also addressing the inflammatory response caused by the infection. Prompt and effective treatment is crucial to prevent permanent vision loss or other complications.
• Analyze the relationship between Acanthamoeba keratitis and the topics of protozoan and helminthic infections of the skin and eyes, and discuss the broader implications for public health.
  • Acanthamoeba keratitis is a prime example of a protozoan infection that can affect the skin and eyes, as it primarily targets the cornea of the eye. This infection highlights the importance of understanding the epidemiology, pathogenesis, and clinical manifestations of protozoan and helminthic infections that can impact these sensitive areas of the body. From a public health perspective, the prevalence of Acanthamoeba keratitis, particularly among contact lens users, underscores the need for improved education, prevention strategies, and effective treatment options to mitigate the burden of this potentially vision-threatening infection. Addressing Acanthamoeba keratitis also requires a multifaceted approach that considers factors such as water quality, hygiene practices, and the development of more robust disinfection methods for contact lenses and related products.

Related terms

Acanthamoeba:

A genus of free-living, opportunistic protozoan parasites that can infect the human eye, central nervous system, and other organs.

Keratitis:

Inflammation of the cornea, the clear, dome-shaped front part of the eye.

Opportunistic Infection: An infection caused by a microorganism that takes advantage of a weakened or compromised immune system.