**Question:** Which of the following statement is true regarding Acanthamoeba keratitis?

A. Acanthamoeba keratitis is a rare condition affecting contact lens wearers.
B. The condition is caused by bacteria, making option A incorrect.
C. Acanthamoeba keratitis is more common in individuals with a history of corneal trauma.
D. The infection is typically treated with oral antibiotics alone, ignoring topical therapy.

**Correct Answer:**

Acanthamoeba keratitis refers to an infectious disease of the cornea caused by the Acanthamoeba genus of amoebae. The statement is true regarding the rarity of the condition and its association with contact lens usage:

**Core Concept:** Acanthamoeba is an amoeba belonging to the genus Acanthamoeba, which is part of the free-living amoebae. These amoebae are commonly found in soil, water, and dust, and can cause various infections in humans, including Acanthamoeba keratitis.

**Why the Correct Answer is Right:** Acanthamoeba keratitis is indeed a rare condition, especially in comparison to other corneal infections caused by viruses, fungi, or bacteria. The statement mentions that the condition is more common in contact lens wearers, highlighting the risk factors associated with the disease. Wearing contact lenses increases the risk of Acanthamoeba keratitis due to the prolonged exposure of the cornea to environmental amoebae.

**Why Each Wrong Option is Incorrect:**

**Option B:** This statement is incorrect as Acanthamoeba keratitis is caused by amoebae, not bacteria. The infection is typically treated with a combination of topical and oral antifungal medications, usually terbinafine and fluconazole, respectively.

**Option C:** While corneal trauma increases the risk of Acanthamoeba keratitis, it is not the sole risk factor. Wearing contact lenses is the main risk factor. Injuries to the cornea can facilitate the entry of Acanthamoeba into the cornea, but the primary cause is contact lens usage.

**Option D:** This statement is incorrect because Acanthamoeba keratitis requires a combination of topical and oral antifungal medications, as mentioned earlier. Ignoring topical therapy is counterproductive and may lead to delayed healing and worsened prognosis.

**Answer Explanation:**

The correct answer (A) highlights the fact that Acanthamoeba keratitis is a rare condition and specifically mentions the increased risk associated with contact lens usage. The infection is caused by Acanthamoeba, which are amoebae, not bacteria. Treatment for Acanthamoeba keratitis typically involves a combination of topical and oral antifungal medications, such as terbinafine and fluconazole, respectively.

Understanding the correct answer and the rationale behind each wrong option helps medical students and residents develop a comprehensive understanding of the disease, its risk factors, and appropriate treatment. This knowledge is crucial for accurate diagnosis and