A 58-year-old woman 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, a mid-dilated fixed pupil, corneal edema, and intraocular pressure of 68 mmHg. Gonioscopy reveals a closed angle. The right eye is normal with IOP 14 mmHg and an open angle on gonioscopy. What is the most appropriate immediate management?

Explanation

## Acute Primary Angle-Closure Glaucoma: Emergency Management ### Clinical Presentation Recognition **Key Point:** The vignette describes classic acute angle-closure glaucoma: sudden severe pain, blurred vision, halos, mid-dilated fixed pupil, corneal edema, markedly elevated IOP (68 mmHg), and gonioscopic confirmation of angle closure. ### Management Algorithm ```mermaid flowchart TD A[Acute angle-closure glaucoma diagnosed]:::outcome --> B{Corneal clarity?}:::decision B -->|Clear cornea| C[Proceed directly to laser iridotomy]:::action B -->|Edema present| D[Start maximum medical therapy]:::action D --> E[Reduce IOP to allow gonioscopy]:::action E --> F[Perform laser peripheral iridotomy]:::action F --> G[Prophylactic iridotomy on fellow eye]:::action G --> H[Resolved acute attack]:::outcome ``` ### Why Medical Therapy First? **High-Yield:** When corneal edema is present (as in this case), the cornea is too opaque for effective laser energy transmission. The lens cannot focus the laser beam accurately through the edematous cornea, making iridotomy technically difficult or impossible. **Clinical Pearl:** Maximum medical therapy is the bridge to definitive treatment: - **Topical agents:** Beta-blockers (timolol), alpha-2 agonists (brimonidine), prostaglandin analogues - **Systemic agents:** Oral acetazolamide (500 mg BD) or IV acetazolamide (500 mg) - **Osmotic agents:** IV mannitol or oral glycerol (if needed for rapid IOP reduction) **Key Point:** The goal is to reduce IOP sufficiently (typically to <40 mmHg) to allow corneal edema to resolve, restoring clarity for safe laser iridotomy. ### Definitive Treatment Once corneal clarity is restored (usually within 2–6 hours of medical therapy), laser peripheral iridotomy is performed on the affected eye. Prophylactic iridotomy must also be performed on the fellow eye (right eye in this case) because it has a narrow angle and is at high risk of acute closure. ### Why Not Immediate Iridotomy? Despite the urgency of the condition, attempting laser iridotomy through corneal edema risks: - Inaccurate laser beam delivery - Incomplete iridotomy - Corneal damage - Failure to resolve the acute attack [cite:Khurana Ophthalmology Ch 12]