In Holmes-Adie pupil all are true except-
**Core Concept**
Holmes-Adie pupil is a condition characterized by a tonic pupil, which is a type of pupil that exhibits abnormal reaction to light and accommodation. It is a result of damage to the ciliary ganglion, leading to a disruption in the parasympathetic innervation of the iris sphincter muscle.
**Why the Correct Answer is Right**
The Holmes-Adie pupil is typically unilateral and is associated with a dilated pupil that reacts slowly to light. This is due to the denervation of the iris sphincter muscle, which is mediated by the parasympathetic nervous system. The ciliary ganglion, which is located in the posterior orbit, plays a crucial role in transmitting parasympathetic signals to the iris sphincter muscle. The Holmes-Adie pupil is often accompanied by a loss of deep tendon reflexes (areflexia) and may be associated with other neurological conditions.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because the Holmes-Adie pupil is typically unilateral, whereas Option A suggests a bilateral involvement.
**Option B:** This option is incorrect because the Holmes-Adie pupil is not typically associated with a constricted pupil, but rather a dilated pupil that reacts slowly to light.
**Option C:** This option is incorrect because the Holmes-Adie pupil is not typically associated with a normal or near-normal reaction to light, but rather a delayed reaction.
**Clinical Pearl / High-Yield Fact**
The Holmes-Adie pupil is a classic example of a tonic pupil, which can be distinguished from a pharmacologically dilated pupil by the presence of a mid-dilated pupil that reacts slowly to light. The presence of a Holmes-Adie pupil should prompt further investigation for underlying neurological conditions.
**Correct Answer:** A.