**Question:** Pupil in Acute Attack of Ant. Uveitis is

A. Miosis
B. Pupillary Dilatation
C. Equal and Brisk Responses
D. Constriction

**Core Concept:**
Anti-Uveitis refers to the immune response targeting the uveal tract, which includes the iris, ciliary body, and choroid. Uveitis is an inflammation of the uveal tract. In an acute attack, the pupil response can provide valuable information about the severity and stage of the inflammation.

**Why the Correct Answer is Right:**
In an acute attack of anti-uveitis, the pupil exhibits mydriasis (pupillary dilatation), as the inflammatory response leads to a decrease in the number of active mydriatic reflex neurons and an increase in the number of active constrictor neurons. This results in a pupil size that is significantly larger than normal (Option B is incorrect).

**Why Each Wrong Option is Incorrect:**
A. Miosis is the opposite of mydriasis, referring to a narrowing of the pupil, which would not be observed in an acute attack of anti-uveitis.
C. Equal and brisk responses refer to the pupillary light reflexes, not the size of the pupil. In an acute attack of anti-uveitis, these responses may be affected, but the main focus is on the size of the pupil, not the reflexes themselves (Options A and C are incorrect).
D. Constriction refers to a narrowing of the pupil. In contrast to constriction, mydriasis or pupillary dilatation would be observed in an acute attack of anti-uveitis (Option D is incorrect).

**Clinical Pearl:**
In a clinical scenario, understanding the pupillary response can help differentiate between different types of uveitis, as well as assess the severity and stage of the inflammation. For example, in posterior uveitis, pupillary response may be normal or brisk, while in panuveitis, the pupil may be constricted due to involvement of the ciliary body. A dilated and fixed pupil indicates severe inflammation and indicates involvement of the iris and ciliary body.

**Why the Correct Answer is Right:**
In an acute attack of anti-uveitis, the pupil size is typically dilated due to the loss of mydriatic reflex neurons and increased constrictor neurons. This results in a larger pupil size than normal.

**Why Each Wrong Option is Incorrect:**
Option A (miosis) represents a narrowing of the pupil, which would not be observed in an acute attack of anti-uveitis. Option C (equal and brisk responses) pertains to the pupillary light reflex, not the size of the pupil. Option D (constriction) refers to a narrowing of the pupil, which is not a characteristic of an acute attack of anti-uveitis.