What medications are recommended for managing chronic open‑angle glaucoma and acute angle‑closure glaucoma?

Drugs to Control Glaucoma

For chronic open-angle glaucoma, start with prostaglandin analogs (latanoprost, bimatoprost, or travoprost) as first-line therapy; for acute angle-closure glaucoma, use immediate combination medical therapy with topical beta-blockers, alpha-2 agonists, carbonic anhydrase inhibitors, and systemic hyperosmotic agents, followed by urgent laser iridotomy.

Chronic Open-Angle Glaucoma (POAG)

First-Line Treatment: Prostaglandin Analogs

Prostaglandin analogs are the preferred initial medical therapy because they provide the most efficacious IOP reduction with once-daily dosing and excellent tolerability 1. Network meta-analysis demonstrates:

• Bimatoprost: 5.61 mmHg reduction (most efficacious)
• Latanoprost: 4.85 mmHg reduction (best tolerability profile)
• Travoprost: 4.83 mmHg reduction
• Tafluprost: 4.37 mmHg reduction 2, 3

The within-class differences are small and likely not clinically meaningful 2. Choose latanoprost if tolerability is a concern, or bimatoprost if maximum IOP reduction is needed 2.

Second-Line Options

When prostaglandin analogs are contraindicated, not tolerated, or insufficient:

Beta-adrenergic antagonists (timolol, levobunolol, betaxolol):

• Timolol: 3.70 mmHg reduction 3
• Dosed once or twice daily
• Avoid nighttime dosing - associated with limited efficacy and may worsen visual field progression via nocturnal blood pressure reduction 1
• Use cardioselective betaxolol in patients with obstructive airway disease 1

Alpha-2 adrenergic agonists (brimonidine):

• 3.59 mmHg reduction 3
• Useful as adjunctive therapy

Carbonic anhydrase inhibitors:

• Topical (dorzolamide, brinzolamide): 15-20% IOP reduction 1
• Oral (acetazolamide, methazolamide): 20-30% IOP reduction for severe cases 1
• Contraindicated in sulfonamide allergy 1

Rho kinase inhibitors (netarsudil):

• 10-20% IOP reduction
• Newer agent with unique mechanism 1

Combination Therapy

Fixed combination latanoprost/timolol provides superior IOP lowering compared to individual components for patients requiring multiple medications 2.

Target IOP Strategy

Set target IOP at 20% lower than baseline mean IOP 1. If baseline pressure is markedly elevated, a 20% reduction may be insufficient - adjust target lower. Reassess at each visit and lower further if optic nerve deterioration occurs 1.

Acute Angle-Closure Glaucoma (AACC)

Immediate Medical Management

Use aggressive combination therapy simultaneously 4:

1. Topical beta-adrenergic antagonists (timolol)
2. Topical alpha-2 adrenergic agonists (brimonidine)
3. Topical or IV carbonic anhydrase inhibitors (acetazolamide 500mg IV or oral)
4. Systemic hyperosmotic agents (mannitol IV or oral glycerol) for rapid IOP reduction 4, 5

Parasympathomimetics (Pilocarpine)

• May help by constricting pupil and opening angle
• Often ineffective initially when IOP is markedly elevated due to pressure-induced iris sphincter ischemia 4
• Use after IOP begins to decrease with other agents

Critical Caveat

Avoid parasympathomimetics in secondary pupillary block (from gas, oil, vitreous, or lens) - use mydriatics instead 4.

Definitive Treatment

Laser peripheral iridotomy (LPI) is the definitive treatment and should be performed as soon as corneal clarity permits 4, 6. Medical therapy serves only to lower IOP temporarily and clear corneal edema to enable LPI.

Important Pitfalls

• Beta-blockers and carbonic anhydrase inhibitors may be initially ineffective in AACC due to ciliary body ischemia 4
• Prostaglandins are not appropriate for acute angle-closure - they work too slowly
• All topical glaucoma medications except parasympathomimetics can be used for angle-closure glaucoma once the acute attack is controlled 5
• After successful LPI, if IOP remains elevated, manage as chronic open-angle glaucoma with prostaglandin analogs as first-line 4