What are the primary techniques for managing glaucoma?

Glaucoma Management Techniques

The primary techniques for managing glaucoma are medical therapy (topical medications), laser trabeculoplasty, and incisional surgery, all aimed at lowering intraocular pressure (IOP) to prevent progressive optic nerve damage and preserve visual function. 1

Core Management Strategy

The fundamental goal is to lower IOP sufficiently to prevent visual field loss and optic nerve damage that would impair quality of life. 1 Lowering IOP by at least 25% from baseline has been demonstrated to slow progression of primary open-angle glaucoma (POAG). 2

Target IOP Guidelines

Set specific IOP targets based on glaucoma severity: 3

• Mild glaucoma: Target 15-17 mmHg 3
• Moderate glaucoma: Target 12-15 mmHg 3
• Severe glaucoma: Target 10-12 mmHg 3

For glaucoma suspects without established disease, aim for approximately 20% reduction from baseline IOP measurements. 1

First-Line Medical Therapy

Prostaglandin analogs are the preferred initial medical treatment because they provide the most efficacious IOP reduction, are well-tolerated, and require only once-daily dosing. 1 Latanoprost reduces IOP by 6-8 mmHg in patients with baseline pressures of 24-25 mmHg, demonstrating equivalent efficacy to timolol 0.5% dosed twice daily. 4

Alternative First-Line Options

When prostaglandin analogs are contraindicated or not tolerated: 1

• Topical beta-adrenergic antagonists (timolol, betaxolol) provide good efficacy and tolerability 1
• Avoid nighttime dosing of beta-blockers as this may contribute to visual field progression through nocturnal blood pressure reduction 1
• Use cardioselective beta-blockers (betaxolol) in patients with obstructive airway disease to minimize pulmonary adverse effects 1

Second-Line Medical Therapy

Add adjunctive agents when monotherapy fails to achieve target IOP: 1, 5

• Alpha-2 adrenergic agonists (brimonidine) 1
• Topical carbonic anhydrase inhibitors (dorzolamide, brinzolamide) - provide 15-20% IOP reduction 1
• Rho kinase inhibitors (netarsudil) - provide 10-20% IOP reduction 1

Third-Line Options

Parasympathomimetics (pilocarpine) are reserved for third-line therapy due to side effect profiles. 6, 7

Laser Trabeculoplasty

Laser trabeculoplasty can be used as primary therapy for ocular hypertension and glaucoma suspects, or as adjunctive treatment when medical therapy is insufficient. 1 This technique increases aqueous outflow through the trabecular meshwork. 5

Clinical trial data show: 1

• Laser trabeculoplasty achieves approximately 30-38% IOP reduction 1
• Outcomes vary by race, with patients of African descent responding better to laser as initial therapy 1

Incisional Surgery

Trabeculectomy provides the greatest IOP reduction (46-60%) and is indicated when medical and laser therapies fail to achieve target IOP or when advanced disease requires aggressive pressure lowering. 1

Surgical options include: 5

• Trabeculectomy - most effective at lowering IOP 1
• Glaucoma drainage tube implantation 5
• Ciliary body cyclodestruction 5

Surgery achieves superior IOP control compared to medical therapy, with trabeculectomy reducing IOP by 58-60% versus 38-49% with medications alone. 1 However, in long-term follow-up, initial filtering surgery was equally effective as medical therapy at preventing visual field progression, though with slightly greater IOP reduction. 1

Monitoring Requirements

All patients require long-term monitoring regardless of treatment modality. 1

• Untreated low-risk patients: Every 12-24 months 2
• Treated or high-risk patients: Every 3-6 months until stable 2

Each visit must include: 2

• Visual acuity measurement 2
• Slit-lamp biomicroscopy 2
• IOP measurement 2
• Periodic optic nerve head and retinal nerve fiber layer evaluation 2

Critical Decision Points

Any patient showing optic nerve deterioration, retinal nerve fiber layer loss, or visual field changes consistent with glaucoma has progressed from suspect to established POAG and requires immediate treatment. 1

For glaucoma suspects, treatment decisions depend on risk stratification. Untreated patients with baseline IOP ≥26 mmHg and central corneal thickness ≤555 μm have a 36% risk of developing optic nerve damage, compared to only 2% risk for those with IOP <24 mmHg and corneal thickness >588 μm. 1

Common Pitfall

Do not rely solely on IOP levels to diagnose or manage glaucoma. Population studies show 13-71% of patients with IOP >21 mmHg do not have glaucomatous damage, while many patients with normal-tension glaucoma develop characteristic optic nerve and visual field changes without elevated IOP. 1 Always correlate IOP measurements with structural optic nerve assessment and visual field testing. 1