**Question:** Pinpoint pupils are seen in haemorrhage of

A. Ciliary body
B. Choroid
C. Retina
D. Anterior chamber

**Core Concept:**
Pinpoint pupils are a characteristic finding in certain clinical scenarios, representing complete absence of light reflex due to damage to the pupillary margin. The ciliary body, choroid, retina, and anterior chamber all contribute to pupillary light reflex, which is essential for normal pupillary size and shape.

**Why the Correct Answer is Right:**
Pinpoint pupils are observed in cases of haemorrhage involving the anterior segment of the eye. The correct answer, D (anterior chamber), is the correct option as the anterior chamber contains the iris and the pupillary margin, which is responsible for producing the light reflex. Damage to the anterior chamber due to hemorrhage results in complete absence of the light reflex, leading to pinpoint pupils.

**Why Each Wrong Option is Incorrect:**

A. Ciliary body: Though important in regulating pupil size, haemorrhage in the ciliary body would not result in complete absence of light reflex, leading to non-pinpoint pupils.
B. Choroid: Damage to the choroid would affect the retinal blood supply but not the light reflex, maintaining the pupil's response to light.
C. Retina: Similar to choroid, retinal haemorrhage would affect vision but not the light reflex, resulting in non-pinpoint pupils.

**Clinical Pearl:**
Pinpoint pupils are a crucial clinical sign in assessing ocular trauma, particularly in cases involving the anterior segment. This helps differentiate pinpoint pupils from non-pinpoint pupils, which often occur due to other causes like mydriasis or constriction of the pupil. An understanding of the anatomy of the eye, specifically the anterior segment, is vital for accurate interpretation of pupillary findings.