In Adie's tonic pupil, denervation supersensitivity can be demonstrated using which concentration of pilocarpine, and what is the expected response?

• A 1% pilocarpine causes constriction of the Adie's pupil but not the normal pupil
• B 0.1% (dilute) pilocarpine causes constriction of the Adie's pupil but minimal/no constriction of normal pupil ✓
• C 4% pilocarpine causes constriction of the Adie's pupil only
• D 0.5% tropicamide causes dilation of Adie's pupil and not the normal pupil

Explanation

Adie's tonic pupil results from postganglionic parasympathetic denervation of the iris sphincter. Due to denervation supersensitivity, the denervated sphincter muscle develops upregulated acetylcholine receptors and responds to very dilute cholinergic agents. Instillation of 0.1% pilocarpine (not clinically effective in a normal eye) causes brisk constriction of the tonic pupil while having minimal effect on the normal contralateral pupil. Full-strength pilocarpine (1–4%) would constrict both pupils. This test is used diagnostically to confirm Adie's tonic pupil.

Reference: Khurana Comprehensive Ophthalmology, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.