**Question:** Hypopyon consists of: March 2013

A. Cells
B. Blood
C. Pus
D. Protein

**Core Concept:** Hypopyon is a condition characterized by the presence of an opaque, cloudy accumulation in the anterior chamber of the eye. It is typically caused by inflammation or infection, leading to increased cellular or protein content within the aqueous humor.

**Why the Correct Answer is Right:** Hypopyon is mainly composed of cells, specifically neutrophils, which are part of the immune response and indicate inflammation. In this context, blood, protein, and pus (which is a type of pus containing increased numbers of neutrophils and other inflammatory cells) are incorrect options.

**Why Each Wrong Option is Incorrect:**

A. Cells (neutrophils): Although cells are present in hypopyon, the main component of hypopyon is neutrophils, which are part of the immune response to inflammation.

B. Blood: Blood is not the primary component of hypopyon, as it is primarily composed of cells and proteins, not blood cells.

C. Pus: Pus contains a higher number of neutrophils compared to hypopyon and is an oversimplification of hypopyon, as it includes other inflammatory cells.

D. Protein: While proteins are present in hypopyon due to inflammation, the main component is cells, specifically neutrophils.

**Clinical Pearl:** Hypopyon is a clinical sign indicative of ocular inflammation or infection, prompting the need for a thorough ophthalmological evaluation and potential further investigations to determine the underlying cause.

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**Correct Answer:** A. Cells (neutrophils)

Hypopyon is primarily composed of neutrophils, which are part of the immune response to inflammation. This is the main component of hypopyon, making option A the correct answer. The other options (blood, pus, and protein) are either incorrect or not the primary component of hypopyon. Understanding the cellular composition of hypopyon is essential for accurate diagnosis and management of the underlying condition.