What are the treatment options for glaucoma?

Treatment Options for Glaucoma

Prostaglandin analogs are the most effective first-line medical therapy for glaucoma due to their superior efficacy in lowering intraocular pressure (IOP), once-daily dosing, and favorable safety profile. 1

Medical Therapy Options

Medical therapy is the most common initial intervention for glaucoma management, with the goal of maintaining IOP at a level that prevents visual field loss affecting quality of life. Treatment options include:

First-Line Therapy

• Prostaglandin analogs (PGAs)
  • Most efficacious (5.61 mmHg IOP reduction for bimatoprost)
  • Once-daily dosing
  • Well-tolerated systemic profile
  • Examples: bimatoprost, latanoprost, travoprost, tafluprost
  • Side effects: conjunctival hyperemia, eyelash growth, periorbital fat atrophy 1

Second-Line/Adjunctive Therapies

• Beta-adrenergic antagonists (Beta-blockers)

  • Examples: timolol, betaxolol, levobunolol, carteolol
  • Contraindications: asthma, COPD, bradycardia, heart block 2
  • Avoid nighttime dosing due to reduced efficacy and potential for nocturnal blood pressure reduction 1

• Alpha-2 adrenergic agonists

  • Examples: brimonidine, apraclonidine
  • Side effects: allergic reactions, dry mouth

• Carbonic anhydrase inhibitors

  • Topical: dorzolamide, brinzolamide
  • Oral: acetazolamide, methazolamide
  • Oral forms can reduce IOP by 20-30% but have more systemic side effects 1, 3

• Rho kinase inhibitors

  • Example: netarsudil
  • Mechanism: increases trabecular outflow, decreases episcleral venous pressure 1

Target IOP and Treatment Algorithm

1. Establish target IOP:

   • Aim for 20-25% reduction from baseline IOP 1
   • For patients with more severe damage or rapid progression, target greater reductions
   • Regularly reassess target IOP based on disease progression

2. Treatment algorithm:

   • Start with PGA monotherapy (bimatoprost, latanoprost, or travoprost) 1
   • If target IOP not achieved, either:
     • Switch to alternative PGA, or
     • Add a second medication from a different class 1
   • For combination therapy, consider fixed combinations to improve adherence 4
   • If medical therapy fails to achieve target IOP, consider laser trabeculoplasty or surgical options 1

Combination Therapy Considerations

• Fixed-combination medications improve adherence and eliminate washout effect 4
• PGA-timolol fixed combinations are effective but slightly less so than unfixed combinations 4
• Alpha-2 agonist-PGA and carbonic anhydrase inhibitor-PGA combinations are at least as effective as beta-blocker-PGA combinations 4

Surgical and Laser Options

When medical therapy is insufficient:

• Laser trabeculoplasty is as effective as medical treatment for first-line therapy 1
• Trabeculectomy is more effective than medications in reducing IOP but has more complications 1
• Anti-fibrotic agents (mitomycin-C, 5-Fluorouracil) improve IOP control after trabeculectomy 1

Important Clinical Considerations

• Adherence challenges: Multiple medications and complex regimens reduce adherence
• Cost considerations: Generic PGAs may be more affordable than newer agents 5
• Side effect management: Monitor for local and systemic side effects
• Regular monitoring: Assess IOP, optic nerve structure, and visual fields to determine if target IOP is appropriate

Pitfalls to Avoid

1. Underestimating non-adherence: Poor adherence is a major cause of treatment failure
2. Overlooking systemic contraindications: Beta-blockers can worsen asthma, COPD, and bradycardia 2
3. Continuing ineffective medications: If a medication shows minimal IOP reduction, consider switching rather than adding another agent
4. Delaying surgical intervention: Don't persist with ineffective medical therapy when surgery may be more appropriate
5. Neglecting to adjust target IOP: Failure to lower target IOP when progression occurs despite treatment

Remember that the ultimate goal of glaucoma treatment is to preserve visual function and quality of life by preventing progressive optic nerve damage through effective IOP control.