A 58-year-old woman from rural Maharashtra presents to the emergency department with sudden onset of severe left eye pain, blurred vision, and nausea for the past 4 hours. She reports seeing halos around lights. On examination, the left eye shows conjunctival injection, corneal edema, mid-dilated pupil (5 mm), and intraocular pressure of 58 mmHg. The anterior chamber is shallow. Gonioscopy cannot be performed due to corneal haze. What is the most appropriate immediate management?

Explanation

## Acute Angle-Closure Glaucoma: Emergency Management ### Clinical Presentation Recognition **Key Point:** The classic triad of acute angle-closure glaucoma (ACG) is: 1. Sudden severe eye pain 2. Corneal edema (blurred vision, halos) 3. Markedly elevated IOP (typically >40 mmHg) The shallow anterior chamber and mid-dilated pupil are pathognomonic findings. ### Immediate Medical Management (Before Laser) **High-Yield:** The sequence is critical — medical therapy FIRST to lower IOP and clear cornea, THEN laser treatment. **Rationale for each agent:** - **Topical beta-blockers (timolol):** Reduces aqueous humor production; works within 30 minutes - **Topical alpha-2 agonists (brimonidine):** Reduces production and increases uveoscleral outflow - **Pilocarpine 1% (miotic):** Pulls iris away from angle by contracting ciliary muscle; however, **only effective once IOP is <40 mmHg** (otherwise pupil is already mid-dilated and unresponsive) - **Oral/IV acetazolamide:** Carbonic anhydrase inhibitor; reduces aqueous production by ~50%; onset 30–60 minutes - **Topical glycerol or IV mannitol:** Osmotic agents; shrink vitreous volume and deepen anterior chamber ### Why Laser Cannot Be Done Immediately **Clinical Pearl:** Corneal edema from elevated IOP prevents clear visualization of the iris and angle structures. The cornea must be cleared first using osmotic agents (glycerol drops) and IOP-lowering medications. ### Sequence of Treatment ```mermaid flowchart TD A[Acute ACG Presentation]:::outcome --> B[Initiate Medical Therapy]:::action B --> C[Topical: Timolol + Brimonidine + Pilocarpine 1%]:::action B --> D[Systemic: Acetazolamide IV/oral]:::action B --> E[Osmotic: Glycerol drops or IV Mannitol]:::action C --> F{IOP decreased?<br/>Cornea clear?}:::decision D --> F E --> F F -->|Yes| G[Laser Peripheral Iridotomy]:::action F -->|No| H[Repeat medical therapy<br/>Consider AC paracentesis]:::action G --> I[Prophylactic iridotomy<br/>fellow eye]:::action ``` ### Definitive Treatment **Key Point:** Laser peripheral iridotomy (LPI) is the definitive treatment. It creates a communication between posterior and anterior chambers, allowing iris to fall back and open the angle. **Prophylaxis:** The fellow eye must receive prophylactic LPI even if asymptomatic, as it has the same anatomical risk (shallow AC, narrow angles). ### Why Anterior Chamber Paracentesis? Reserved for cases where: - Medical therapy fails after 30–60 minutes - Cornea remains too opaque for laser visualization - IOP remains >50 mmHg despite maximal medical therapy It is NOT first-line in this case because medical therapy has not yet been attempted. [cite:Khurana Comprehensive Ophthalmology Ch 10]