Emergency Treatment of Acute Angle-Closure Glaucoma
Immediately administer topical aqueous suppressants (beta-blockers, alpha-2 agonists, and carbonic anhydrase inhibitors) along with oral or IV hyperosmotic agents to rapidly lower IOP, followed by laser peripheral iridotomy (LPI) once the cornea clears—do not attempt to correct the temporary cylindrical refractive error from corneal edema, as it will resolve spontaneously once IOP is controlled. 1, 2
Immediate Medical Management
The priority is rapid IOP reduction to prevent permanent optic nerve damage:
Topical therapy should include all of the following 1, 2:
- Beta-adrenergic antagonists (e.g., timolol 0.5%)
- Alpha-2 adrenergic agonists
- Carbonic anhydrase inhibitors (topical)
- Parasympathomimetics (pilocarpine 4%) once IOP begins to decrease
Systemic therapy with oral or intravenous hyperosmotic agents (e.g., mannitol, glycerol) to rapidly reduce IOP 1, 2
The combination of these agents typically reduces IOP from severely elevated levels (often >40-60 mmHg) to more manageable levels within 15-60 minutes 3
Definitive Treatment
Laser peripheral iridotomy (LPI) is the definitive treatment once IOP is controlled and corneal clarity returns 1, 2. This relieves the pupillary block mechanism responsible for the acute attack 1, 4.
Alternative approaches include:
- Argon laser peripheral iridoplasty (ALPI) can be performed immediately as first-line treatment, which effectively lowers IOP and clears corneal edema within 1-2 hours without systemic medications 3
- Primary lens extraction is increasingly recognized as more effective than LPI alone for long-term outcomes, though technically demanding in the acute setting 2, 5
Management of Corneal Edema and Refractive Error
The cylindrical refractive error is caused by pressure-induced corneal edema (microcystic and stromal edema) and should NOT be corrected with lenses 1, 6. This is a critical pitfall to avoid.
Key points:
- Corneal edema manifests as blurred vision and halos around lights 1, 6
- Assessment of actual refractive status should be postponed until a subsequent visit after the acute episode resolves 1
- The cornea typically clears within 1-2 hours after successful IOP reduction 3
- Any myopic shift that occurs after the acute episode typically resolves within 3 months 7
Fellow Eye Prophylaxis
Perform prophylactic LPI in the fellow eye urgently 1, 2. The untreated fellow eye has approximately 50% risk of acute angle-closure crisis within 5 years 8, 2. Do not delay this treatment, as acute attacks can occur within days 8.
Critical Pitfalls
- Never dilate the pupil in patients with suspected narrow angles until after LPI is performed, as dilation can precipitate acute crisis 6, 8
- Do not delay treatment waiting for ophthalmology consultation if acute angle-closure is suspected—begin medical therapy immediately 6
- Do not attempt refraction during the acute episode when corneal edema is present 1
Prognosis Without Treatment
The natural history is devastating: 48% develop glaucomatous optic neuropathy and 58% have visual acuity worse than 20/40 within 4-10 years following untreated acute angle-closure crisis 1, 6, 2. Untreated eyes can become blind within hours 6.