What is the typical treatment for glaucoma?

Treatment of Glaucoma

Prostaglandin analogs are the first-line medical treatment for glaucoma because they provide the most effective IOP reduction (approximately 5-6 mmHg), require only once-daily dosing, and are well-tolerated. 1

Initial Medical Therapy Approach

First-Line Treatment: Prostaglandin Analogs

• Prostaglandin analogs are the most frequently prescribed and should be initiated first unless contraindications, cost concerns, side effects, or patient refusal preclude their use 1
• Among prostaglandin analogs, bimatoprost achieves the highest IOP reduction (5.61 mmHg at 3 months), followed closely by latanoprost (4.85 mmHg) and travoprost (4.83 mmHg) 1, 2
• Latanoprost offers the most favorable tolerability profile within this class 1
• These medications work by enhancing uveoscleral outflow and require only once-daily administration 1

Second-Line Treatment: Beta-Blockers

• If prostaglandin analogs are not tolerated, timolol 0.5% twice daily is the most effective alternative, achieving IOP reductions of 7-9 mmHg 3, 4
• Timolol 0.1% gel formulation once daily provides equivalent efficacy with improved convenience 3
• Check IOP response within 2-4 weeks of initiation to confirm adequate pressure reduction 3
• Avoid nighttime dosing of beta-blockers as this is associated with limited efficacy and may contribute to visual field progression through nocturnal blood pressure reduction 1
• Nonselective beta-blockers (timolol) block both beta-1 and beta-2 receptors; cardioselective agents (betaxolol) minimize but do not eliminate pulmonary risks 1

Additional Medication Classes

• Alpha-2 adrenergic agonists (brimonidine): 3.59 mmHg IOP reduction 2
• Topical carbonic anhydrase inhibitors (dorzolamide, brinzolamide): 2.42-2.49 mmHg IOP reduction, with potential side effects including allergic reactions, corneal edema, and metallic taste 1, 2
• Rho kinase inhibitors (netarsudil): 10-20% IOP reduction through increased trabecular outflow 1
• Oral carbonic anhydrase inhibitors (acetazolamide): 20-30% IOP reduction, reserved for situations requiring more aggressive pressure lowering 1, 5

Target IOP and Treatment Goals

Set a target IOP that is 20% lower than the mean baseline IOP to prevent visual field loss that would affect quality of life 1

• If baseline pressure is markedly elevated, a 20% reduction may be insufficient 1
• Reassess target IOP at each visit and adjust based on evidence of optic nerve or visual field deterioration 1
• The ultimate goal is maintaining vision and quality of life, not simply achieving a numerical target 1

Combination Therapy

When to Add Second Medication

• Add a second medication when monotherapy fails to achieve target IOP 6, 7
• Fixed combinations (prostaglandin + timolol in single bottle) simplify dosing, improve adherence, avoid washout effects, and reduce preservative exposure 6
• Fixed combination latanoprost-timolol demonstrates better IOP lowering than individual components used as monotherapy 1

Practical Considerations for Multiple Drops

• Instruct patients to wait at least 5 minutes between different eye drops to prevent washout of the first medication 3
• Unfixed combinations may provide slightly better IOP reduction than fixed combinations but with reduced tolerability 6

Surgical and Laser Options

Consider laser trabeculoplasty when medication adherence, cost, convenience, side effects, or risks become limiting factors 1

• Primary surgery (trabeculectomy) lowers IOP more than medication but causes more eye discomfort 1
• Visual field outcomes at 5 years show no significant difference between initial medication and initial surgery 1
• Monitor for IOP spikes if pursuing laser trabeculoplasty 3
• Surgery is typically reserved for patients in whom medical treatment has failed 8, 7

Critical Pitfalls to Avoid

• Never rely on IOP alone for diagnosis—some patients with glaucoma have normal IOP (normal-tension glaucoma), while others with elevated IOP lack glaucomatous damage (ocular hypertension) 8
• Do not prescribe beta-blockers at night due to reduced efficacy and potential for visual field progression 1
• Screen for contraindications: beta-blockers in obstructive airway disease, sulfonamide allergy for carbonic anhydrase inhibitors, kidney stones/aplastic anemia/sickle cell disease for acetazolamide 1, 5
• Ensure proper drop spacing of at least 5 minutes to prevent medication washout 3
• Monitor for adherence issues—complex interventions combining education with personalized adherence strategies may help, though evidence remains insufficient 1

Monitoring Requirements

• Assess IOP response within 2-4 weeks of initiating or changing therapy 3
• Perform regular optic nerve and visual field monitoring to detect progression 1
• If deterioration occurs despite treatment, lower the target IOP further and intensify therapy 1