Which indirect acting cholinergic agonist is used in the preventive management of glaucoma?

Which indirect acting cholinergic agonist is used in the preventive management of glaucoma?

• A. Physostigmine
• B. Demecarium
• C. Neostigmine
• D. Pyridostigmine

Answer: (B)

Indirect-acting cholinergic agonists work by inhibiting acetylcholinesterase, increasing acetylcholine at muscarinic receptors in the eye. This stimulates the iris sphincter and ciliary muscle, causing miosis and enhancing the outflow of aqueous humor through the trabecular meshwork, which lowers intraocular pressure.

For preventive glaucoma management in veterinary patients, a long-acting agent is preferred because it provides sustained effect with less frequent dosing. Demecarium bromide is a long-acting acetylcholinesterase inhibitor used topically to maintain miosis and reduce intraocular pressure over an extended period, making it well suited for prophylaxis after ocular procedures or in animals at risk of glaucoma.

The other agents listed are shorter-acting cholinesterase inhibitors or are used for different indications (such as myasthenia gravis or reversal of neuromuscular blockade), so they are not ideal for long-term glaucoma prophylaxis.