What is the immediate management for acute angle‑closure glaucoma to rapidly lower intra‑ocular pressure and arrange definitive treatment?

Immediate Management of Acute Angle-Closure Glaucoma

Patients with acute angle-closure crisis require immediate medical therapy to rapidly lower intraocular pressure, followed by laser peripheral iridotomy as soon as the cornea clears sufficiently to visualize the iris. 1, 2

Initial Medical Management to Lower IOP

The priority is rapid IOP reduction to relieve symptoms and prevent permanent optic nerve damage. Initiate the following medications immediately:

First-Line Agents (Aqueous Suppressants)

• Topical beta-adrenergic antagonist (e.g., timolol 0.5%) - apply immediately 1, 2
• Topical alpha-2 adrenergic agonist (e.g., brimonidine) - apply immediately 1, 2
• Systemic carbonic anhydrase inhibitor (e.g., acetazolamide 500mg IV or PO) - administer immediately for rapid IOP reduction 1, 3

Second-Line Agents

• Hyperosmotic agents (e.g., oral glycerol or IV mannitol) - use when IOP remains dangerously elevated despite initial therapy 1, 4
• Topical parasympathomimetic (pilocarpine 1-2%) - ONLY after IOP begins to decrease, as the ischemic iris sphincter will not respond when IOP is markedly elevated 1, 2

Critical Caveat About Aqueous Suppressants

Beta-blockers and carbonic anhydrase inhibitors may be initially ineffective because ciliary body ischemia from extremely high IOP reduces their ability to suppress aqueous formation. 1 Despite this limitation, they should still be administered immediately as part of the initial regimen.

Definitive Treatment: Laser Peripheral Iridotomy

Laser peripheral iridotomy (LPI) is the preferred definitive treatment and should be performed as soon as possible after medical therapy begins to clear the corneal edema. 1, 2

Timing and Technique

• Perform LPI immediately once the cornea clears enough to visualize the iris 1, 2
• LPI relieves pupillary block by allowing aqueous to bypass the pupil, eliminating the pressure gradient between posterior and anterior chambers 1
• Measure IOP immediately before and 30 minutes to 2 hours after laser surgery 1
• Prescribe topical corticosteroids postoperatively 1

Alternative Procedures When LPI Cannot Be Performed

If corneal edema prevents laser iridotomy despite medical therapy:

• Corneal indentation with a four-mirror gonioscopic lens, cotton-tipped applicator, or muscle hook tip may break pupillary block 1
• Anterior chamber paracentesis to rapidly lower IOP and clear cornea 1
• Laser peripheral iridoplasty to contract peripheral iris and open the angle 1
• Incisional iridectomy if laser cannot be performed 1

Fellow Eye Management

The fellow eye must be evaluated urgently and receive prophylactic laser peripheral iridotomy as soon as possible, ideally within days. 1

• Approximately 50% of untreated fellow eyes develop acute angle-closure crisis within 5 years 1, 5
• Attacks can occur within days of the initial presentation 1
• Chronic parasympathomimetic therapy is NOT an appropriate alternative to iridotomy for prophylaxis - about 40% of eyes treated with miotics alone still develop AACC within 5 years 1, 5

Post-Treatment Follow-Up

After breaking the acute attack:

• Confirm iridotomy patency by visualizing zonules, anterior lens capsule, or ciliary processes 1
• Perform dark-room gonioscopy with compression to assess extent of peripheral anterior synechiae 1
• Monitor for persistent IOP elevation, which may indicate trabecular damage, PAS formation, or coexisting open-angle glaucoma 1

Natural History Without Treatment

Untreated acute angle-closure crisis causes rapid glaucomatous optic neuropathy, with retinal nerve fiber layer swelling within days, followed by permanent axonal atrophy and potential blindness within months. 1 This underscores the vision-threatening emergency nature of this condition requiring same-day ophthalmologic intervention. 2, 6