A 52yrs old female presented with sudden attack of painful diminsion of vision in right eye along with coloured halos and vomiting following a movie in a theater . On examination , the eye was stony hard.1st drug to be given in the above condition is

**Core Concept**
The patient is presenting with acute angle-closure glaucoma, a medical emergency characterized by a sudden increase in intraocular pressure (IOP) due to blockage of the trabecular meshwork by the iris. This condition can lead to optic nerve damage and vision loss if not promptly treated.

**Why the Correct Answer is Right**
The first-line treatment for acute angle-closure glaucoma is to lower the IOP using topical and systemic medications. **Acetazolamide** is a carbonic anhydrase inhibitor that reduces aqueous humor production, thereby decreasing IOP. It is often administered intravenously in emergency situations to rapidly lower IOP and prevent further optic nerve damage. This medication works by inhibiting the enzyme carbonic anhydrase, which is involved in the production of aqueous humor.

**Why Each Wrong Option is Incorrect**
**Option A:** **Atropine** is an anticholinergic medication that can actually worsen angle-closure glaucoma by dilating the pupils and further blocking the trabecular meshwork.
**Option B:** **Pilocarpine** is a miotic agent that can help treat open-angle glaucoma, but it may not be effective in acute angle-closure glaucoma and can even worsen the condition.
**Option C:** **Latanoprost** is a prostaglandin analog that decreases IOP by increasing uveoscleral outflow, but it is not the first-line treatment in acute angle-closure glaucoma.

**Clinical Pearl / High-Yield Fact**
In acute angle-closure glaucoma, the "red flag" symptom is often a sudden onset of severe eye pain, which is a medical emergency that requires prompt treatment to prevent vision loss.

**Correct Answer:** A. Acetazolamide

✓ Correct Answer: D. Acetazolamide