What is the initial treatment for acute angle glaucoma?

Initial Treatment for Acute Angle-Closure Glaucoma

The initial treatment for acute angle-closure glaucoma (AACC) should be medical therapy to rapidly lower intraocular pressure (IOP), followed by laser peripheral iridotomy (LPI) as soon as possible after the IOP is reduced and corneal edema clears. 1, 2

Medical Management Algorithm

First-Line Medications

• Begin with a combination of the following medications to rapidly reduce IOP:
  • Topical beta-adrenergic antagonists (e.g., timolol) 1, 2
  • Topical alpha2-adrenergic agonists (e.g., brimonidine) 1, 2
  • Topical, oral, or intravenous carbonic anhydrase inhibitors (e.g., acetazolamide 250-500 mg) 1, 3
  • Topical parasympathomimetics (e.g., pilocarpine) 1, 2
  • Oral or intravenous hyperosmotic agents for severe cases 1, 2

Administration Considerations

• Intravenous acetazolamide may provide more rapid relief of ocular tension in acute cases 3, 4
• Systemic hyperosmotic agents are often necessary to achieve rapid IOP reduction 1
• Corneal indentation performed with a four-mirror gonioscopic lens, cotton-tipped applicator, or muscle hook tip may help break pupillary block 1

Important Clinical Considerations

Medication Efficacy Notes

• Aqueous suppressants (beta-blockers, carbonic anhydrase inhibitors) may be initially less effective if the ciliary body is ischemic 1
• Parasympathomimetics (miotics) may be ineffective when IOP is markedly elevated due to pressure-induced ischemia of the pupillary sphincter 1
• In cases of secondary pupillary block (due to intraocular gas, oil, vitreous, or lens-related issues), mydriatics may be more effective than miotics 1, 2

Timing of Definitive Treatment

• Laser peripheral iridotomy (LPI) should be performed as soon as possible after IOP is reduced and corneal edema clears 1
• LPI is the preferred definitive treatment due to its favorable risk-benefit ratio 1, 2
• When LPI cannot be performed immediately, alternative approaches include:
  • Peripheral laser iridoplasty (even with cloudy cornea) 1
  • Anterior chamber paracentesis 1
  • Incisional iridectomy 1

Management of Fellow Eye

• The fellow eye should be evaluated promptly as it is at high risk (approximately 50% risk of AACC within 5 years) 1
• Prophylactic LPI should be performed in the fellow eye as soon as possible if the angle is anatomically narrow 1
• Chronic parasympathomimetic therapy is not an appropriate alternative for prophylaxis 1

Common Pitfalls to Avoid

• Delaying definitive treatment with LPI once IOP is controlled 1
• Relying solely on topical timolol without additional medications, as it is not sufficiently effective alone for AACC 5
• Using miotics in angle-closure glaucoma secondary to ciliochoroidal detachment, as this may worsen the condition (in these cases, cycloplegia is preferred) 6
• Failing to recognize AACC in patients presenting with headache, nausea, and visual disturbances, especially in non-ophthalmology settings 7

Long-Term Management

• After successful LPI, additional treatment may be needed if:

  • Trabecular damage or peripheral anterior synechiae (PAS) formed during angle closure 1
  • The iridotomy becomes occluded (requiring repeat iridotomy) 1
  • Non-pupillary block mechanisms are present (e.g., plateau iris syndrome) 1
  • Pre-existing open-angle glaucoma or other causes of IOP elevation exist 1

• Lens extraction has shown effectiveness in IOP control for primary angle closure with elevated IOP and primary angle closure glaucoma 1, 2