Initial Management of Acute Angle-Closure Glaucoma
The initial management of acute angle-closure glaucoma (AACG) requires immediate medical therapy to lower intraocular pressure (IOP), followed by definitive treatment with laser peripheral iridotomy (LPI) as soon as possible. 1, 2
Emergency Medical Management
First-Line Medications
- Aqueous suppressants:
- Beta-adrenergic antagonists (e.g., timolol)
- Alpha2-adrenergic agonists (e.g., apraclonidine)
- Carbonic anhydrase inhibitors (topical, oral, or IV)
- Hyperosmotic agents (oral or IV) for rapid IOP reduction
- Parasympathomimetics (with caution)
Important note: Aqueous suppressants may initially have decreased efficacy if the ciliary body is ischemic. Parasympathomimetics may be ineffective when IOP is markedly elevated due to pressure-induced ischemia of the pupillary sphincter. 1
Additional Measures
- Corneal indentation using a four-mirror gonioscopic lens, cotton-tipped applicator, or muscle hook to help break pupillary block 1
- Anterior chamber paracentesis if medication fails to lower IOP quickly 1, 3
Definitive Treatment
Laser Peripheral Iridotomy (LPI)
- Timing: Perform as soon as IOP is lowered and corneal edema clears 1, 2
- Purpose: Creates a bypass for aqueous humor, eliminates pressure gradient between posterior and anterior chambers, and prevents formation of peripheral anterior synechiae (PAS) 2
- Target size: At least 100 microns, ensuring patency by visualizing fluid flow or structures behind the iris 2
When LPI Cannot Be Performed
- Laser peripheral iridoplasty to temporarily open the angle 1, 3
- Incisional iridectomy if laser treatment is not possible 1
- Consider lens extraction (phacoemulsification) especially in patients with coexisting cataract 1, 4
Post-Procedure Management
- Topical corticosteroids to reduce inflammation 2
- IOP check within 30 minutes to 2 hours post-procedure 2
- Follow-up to confirm iridotomy patency and assess angle 2
Fellow Eye Management
- Prophylactic LPI should be performed promptly in the fellow eye if the chamber angle is anatomically narrow 1, 2
- Timing: As soon as possible, as attacks can occur within days of the initial presentation 1
- Note: Chronic parasympathomimetic therapy is NOT an appropriate alternative to iridotomy for prophylaxis 1
Special Considerations
Contraindications and Cautions
- Timolol should not be used alone in angle-closure glaucoma as it has little effect on pupil size 5
- Acetazolamide long-term administration is contraindicated in chronic non-congestive angle-closure glaucoma as it may mask worsening glaucoma while permitting organic closure of the angle 6
Persistent Elevated IOP After LPI
- Consider lens extraction, especially in older patients 1, 4
- Evaluate for other mechanisms of angle closure (e.g., plateau iris syndrome) 2
- Additional treatments may include goniosynechialysis, trabeculectomy, or cyclophotocoagulation 3
Clinical Pearls
- Do not delay definitive treatment
- Do not assume all miosis requires dilation
- Do not miss secondary causes of angle closure that may persist after iridotomy
- Do not overlook the fellow eye 2
Prompt recognition and treatment of AACG is critical to prevent permanent damage to the optic nerve, trabecular meshwork, iris, lens, and cornea. The goal is to rapidly lower IOP to relieve symptoms and clear corneal edema, making subsequent definitive laser treatment possible.