What is the diagnosis and treatment for Acute Angle-Closure Glaucoma?

From the Guidelines

Acute angle-closure glaucoma is a serious eye emergency requiring immediate medical attention, and treatment typically begins with medications to rapidly lower intraocular pressure, followed by definitive treatment with laser peripheral iridotomy as soon as possible 1.

Key Considerations

• The initial treatment of acute angle-closure glaucoma (AACC) aims to lower intraocular pressure (IOP) to relieve acute symptoms and prevent further damage 1.
• Medical therapy usually includes topical beta-adrenergic antagonists, topical alpha2-adrenergic agonists, topical, oral, or intravenous carbonic anhydrase inhibitors, topical miotics, and oral or intravenous hyperosmotic agents 1.
• Laser peripheral iridotomy is the preferred surgical treatment for AACC, as it has a favorable risk-benefit ratio and can prevent or retard the formation of peripheral anterior synechiae (PAS) 1.
• The procedure involves creating a small hole in the iris to allow fluid flow between the posterior and anterior chambers, thereby relieving pupillary block and reducing IOP 1.
• Risk factors for AACC include advanced age, female gender, Asian ethnicity, farsightedness, and family history 1.
• Without prompt treatment, permanent vision loss can occur within hours, making this condition a true ophthalmologic emergency requiring immediate specialist consultation 1.

Management Approach

• Medical therapy to break the attack and prepare the patient for laser iridotomy, including topical glycerin, compression, paracentesis, or iridoplasty to clear the view 1.
• Definite evidence for primary angle closure (PAC) mechanism of AACC, and treatment of pathology of secondary AACC and lowering IOP medically or surgically 1.
• Incisional iridectomy or cataract surgery ± goniosynechialysis or trabeculectomy may be considered in certain cases, and scheduling iridotomy in the fellow eye if the chamber angle is anatomically similar 1.
• Dark-room gonioscopy to assess other mechanisms of angle closure, and ascertaining continued patency of iridotomy 1.
• Medical and surgical treatment to lower IOP, including incisional iridotomy or cataract surgery ± goniotomy or trabeculectomy 1.

From the FDA Drug Label

For adjunctive treatment of: ... preoperatively in acute angle-closure glaucoma where delay of surgery is desired in order to lower intraocular pressure. The preferred dosage is 250 mg every four hours, although some cases have responded to 250 mg twice daily on short-term therapy In some acute cases, it may be more satisfactory to administer an initial dose of 500 mg followed by 125 or 250 mg every four hours depending on the individual case.

Acetazolamide is used for the treatment of acute angle-closure glaucoma. The dosage is 250 mg every four hours or 250 mg twice daily on short-term therapy, and in some cases, an initial dose of 500 mg followed by 125 or 250 mg every four hours may be more satisfactory 2 2.

From the Research

Definition and Treatment of Acute Angle Glaucoma

• Acute angle glaucoma is a medical emergency that requires immediate treatment to reduce intraocular pressure and prevent vision loss 3.
• The goal of treatment for acute angle-closure glaucoma is to reduce intraocular pressure quickly with medications or surgery, then prevent the recurrence of the obstruction to aqueous flow by a definitive ophthalmologic procedure 3.

Medications Used to Treat Acute Angle Glaucoma

• Pilocarpine and timolol are commonly used medications to treat acute angle glaucoma 4.
• The hypotensive effect of topical timolol alone was not effective enough to control the intraocular pressure in acute closed-angle glaucoma, but a good hypotensive effect was seen when topical timolol was followed by pilocarpine 4.
• Brimonidine is another medication that can be used to reduce intraocular pressure, but its effectiveness in treating acute angle glaucoma is not well established 5, 6, 7.

Comparison of Brimonidine and Timolol

• A randomized controlled trial comparing the effect of brimonidine and timolol on visual field loss after acute primary angle closure found no significant difference between the two medications 6.
• Another study found that both brimonidine and timolol slowed visual field deterioration in patients with open-angle glaucoma, and both medications improved the mean deviation slopes 7.

Management of Acute Angle Glaucoma

• The management of acute angle glaucoma involves reducing intraocular pressure with medications such as pilocarpine and timolol, and then performing a definitive ophthalmologic procedure to prevent the recurrence of the obstruction to aqueous flow 4, 3.
• Primary care physicians can help decrease POAG-related vision loss by identifying patients with risk factors and referring them for evaluation by an eye specialist 3.