What are the criteria for ending treatment of acute angle closure glaucoma?

Criteria for Ending Acute Angle Closure Treatment

An acute angle-closure crisis (AACC) is considered resolved when intraocular pressure (IOP) is adequately controlled with medical therapy, symptoms have resolved, and definitive laser peripheral iridotomy (LPI) has been successfully performed to relieve pupillary block. 1

Immediate Treatment Goals

The acute episode requires urgent IOP reduction through:

• Aqueous suppressants (beta-blockers, alpha-2 agonists, carbonic anhydrase inhibitors) 1
• Parasympathomimetics (miotics) to constrict the pupil and open the angle 1
• Hyperosmotic agents (oral or IV) for rapid IOP reduction if needed 1

Important caveat: Aqueous suppressants may be initially ineffective if the ciliary body is ischemic from extremely high IOP, and miotics may fail when IOP is markedly elevated due to sphincter ischemia. 1

Criteria for "Breaking" the Acute Attack

The acute crisis is considered broken when:

• IOP decreases to manageable levels (typically below 30-40 mmHg with medical therapy) 1, 2
• Symptoms resolve (pain, nausea, headache cease) 1, 2
• Corneal edema clears sufficiently to allow visualization for laser treatment 1, 2
• The angle opens at least partially, confirmed by gonioscopy 1

Definitive Treatment Completion

Treatment of AACC is not complete until:

1. Laser Peripheral Iridotomy (LPI)

• LPI must be performed in the affected eye once the attack is broken 1, 3
• This relieves pupillary block and prevents recurrence 1, 3
• LPI should be done immediately or soon after breaking the attack 1

2. Fellow Eye Treatment

• Prophylactic LPI must be performed in the fellow eye as soon as possible 1
• Approximately 50% of fellow eyes develop AACC within 5 years if untreated 1
• This can occur within days of the initial presentation 1

Post-Treatment Monitoring Criteria

After definitive LPI, ongoing assessment includes:

Week 3 Benchmark

Treatment failure is defined as IOP ≥25 mmHg on one occasion OR IOP 22-24 mmHg on two occasions after week 3 post-treatment. 1 This indicates need for additional intervention.

Long-term Follow-up Requirements

• Serial gonioscopy to detect progressive peripheral anterior synechiae (PAS) formation 1, 4
• IOP monitoring at appropriate intervals based on degree of angle closure and optic nerve status 1
• Assessment for secondary angle closure from cataract progression 1

Alternative Definitive Treatments

In select cases, treatment may involve:

Early Lens Extraction

• Consider in patients with initial IOP >55 mmHg who are at high risk for uncontrollable IOP 1
• More effective than LPI alone for long-term IOP control in some studies 5, 6
• Should be performed within approximately 5-7 days after breaking the attack if chosen 1

Surgical Iridectomy

• Reserved for cases where laser cannot be performed due to persistent corneal edema 1
• May be combined with filtering surgery if extensive synechial closure is present 1

Critical Pitfalls to Avoid

• Never rely on chronic miotic therapy alone as definitive treatment—40% of eyes treated only with miotics develop AACC within 5 years 1
• Do not delay fellow eye prophylaxis—attacks can occur within days 1
• Anterior chamber paracentesis is only an adjunct to lower IOP temporarily, not definitive treatment 2
• First-year gonioscopic surveillance is essential to detect progressive PAS formation 4