Earliest drug used in acute angle closure glaucoma
## **Core Concept**
Acute angle closure glaucoma is a medical emergency characterized by a sudden increase in intraocular pressure (IOP) due to obstruction of the outflow of aqueous humor. The primary goal of treatment is to rapidly decrease IOP and alleviate symptoms. Pharmacological interventions aim to reduce IOP by either decreasing aqueous humor production or increasing its outflow.
## **Why the Correct Answer is Right**
The correct answer, **. Acetazolamide**, is a carbonic anhydrase inhibitor that decreases the production of aqueous humor, thereby lowering IOP. It acts by inhibiting the enzyme carbonic anhydrase in the ciliary body of the eye, which is responsible for aqueous humor production. This leads to a decrease in IOP. Acetazolamide is often one of the first-line treatments for acute angle closure glaucoma because it can be administered orally or intravenously, allowing for rapid action.
## **Why Each Wrong Option is Incorrect**
- **Option A:** Pilocarpine is a muscarinic receptor agonist that increases the outflow of aqueous humor by causing contraction of the ciliary muscle and thereby opening up the trabecular meshwork. However, its effect is slower compared to IOP-lowering medications like acetazolamide, and it may not be effective if the IOP is very high.
- **Option B:** Latanoprost is a prostaglandin analog that increases the outflow of aqueous humor. While effective in lowering IOP in chronic glaucoma, its onset of action is too slow for the acute management of angle closure glaucoma.
- **Option D:** Timolol is a beta-blocker that decreases aqueous humor production. Although it can be used in the treatment of glaucoma, it may not act as quickly as acetazolamide in the acute setting of angle closure glaucoma.
## **Clinical Pearl / High-Yield Fact**
A key point to remember is that in the acute management of angle closure glaucoma, after administering acetazolamide, pilocarpine can be used once the IOP has started to decrease to help open the angle. It's also crucial to avoid using miotics like pilocarpine initially if the IOP is very high, as they may not be effective and can cause further inflammation.
## **Correct Answer:** . Acetazolamide