First-Line Anti-Glaucoma Medications
Prostaglandin analogs are the first-line medical therapy for glaucoma, with latanoprost, bimatoprost, and travoprost being the most efficacious options, requiring only once-daily dosing and demonstrating superior IOP reduction compared to all other drug classes. 1
Primary Recommendation: Prostaglandin Analogs
Prostaglandin analogs should be initiated as first-line therapy unless specific contraindications exist (such as uveitis, cystoid macular edema, or patient refusal). 1 These agents are the most frequently prescribed eye drops for lowering IOP because they demonstrate the best efficacy and tolerability profile among all glaucoma medications. 1
Specific Drug Selection Within Class
Latanoprost 0.005%, bimatoprost 0.03%, and travoprost 0.004% are the most effective prostaglandin analogs, achieving IOP reductions of 22-39% over 1-12 months of treatment. 1, 2
All three agents (bimatoprost, latanoprost, travoprost) rank among the most efficacious drugs, though within-class differences are small and may not be clinically meaningful. 1
Latanoprost has the best tolerability profile among prostaglandin analogs and is significantly better tolerated than either bimatoprost or travoprost, with better compliance and persistence rates. 3
Administer prostaglandin analogs once daily in the evening for optimal 24-hour IOP control. 1, 4
Expected IOP Reduction
Prostaglandin analogs reduce IOP by 25-35% (approximately 7-8 mmHg from baseline pressures of 25-27 mmHg). 1, 4
In black patients, mean IOP reduction may be up to 1.8 mmHg greater than in non-black patients, though whether this relates to race or iris pigmentation remains unclear. 4
Second-Line Option: Beta-Blockers
If prostaglandin analogs are contraindicated or not tolerated, topical beta-adrenergic antagonists represent the next best option. 1
Specific Beta-Blocker Recommendations
Timolol 0.5% twice daily achieves IOP reductions of approximately 7-9 mmHg, making it the most effective beta-blocker. 5
Timolol 0.5% solution twice daily or timolol 0.1% gel once daily are the standard dosing regimens. 5
Avoid nighttime dosing of beta-blockers, as this is associated with limited efficacy and may contribute to visual field progression via nocturnal reduction of systemic blood pressure. 1
Critical Beta-Blocker Contraindications
Do not prescribe beta-blockers to patients with bronchial asthma, severe COPD, sinus bradycardia, second or third degree AV block, or cardiac failure. 6
Nonselective beta-blockers (timolol) block both beta-1 and beta-2 receptors, creating pulmonary risks. 1
Cardioselective beta-blockers (betaxolol) minimize but do not eliminate pulmonary adverse effects. 1
Additional Medication Classes (Third-Line)
When prostaglandins and beta-blockers are insufficient or contraindicated:
Alpha-2 adrenergic agonists (brimonidine) reduce IOP but are less effective than prostaglandins. 1
Topical carbonic anhydrase inhibitors (dorzolamide, brinzolamide) achieve 15-20% IOP reduction and can be used as adjunctive therapy. 1
Rho kinase inhibitors (netarsudil) provide 10-20% IOP reduction through increased trabecular outflow. 1
Combination Therapy
When monotherapy is insufficient, fixed combinations provide superior IOP control:
The fixed combination of latanoprost plus timolol provides better IOP reduction than either agent alone and is more effective than dorzolamide-timolol combinations. 1, 7, 2
When using multiple eye drops, instruct patients to wait at least 5 minutes between different medications to prevent washout and ensure proper absorption. 5, 7
Oral Therapy (Reserved for Acute Situations)
Oral carbonic anhydrase inhibitors (acetazolamide 250-500 mg) are reserved for acute angle-closure glaucoma or severe IOP elevation requiring rapid reduction. 1, 8
Acetazolamide carries significant risks including Stevens-Johnson syndrome, electrolyte imbalances, renal calculi, and blood dyscrasias. 1, 8
Contraindications to acetazolamide include sulfonamide allergy, kidney stones, aplastic anemia, and sickle cell disease. 1
Critical Implementation Points
Check IOP response within 2-4 weeks of initiation to confirm adequate pressure reduction. 5
Target IOP should be approximately 20% lower than baseline, individualized based on disease severity and progression risk. 1
Avoid allowing the dispensing container tip to contact the eye or surrounding structures to prevent bacterial contamination and potential keratitis. 6
Common Pitfalls to Avoid
Do not use unoprostone as first-line therapy despite its prostaglandin classification—it was the least effective drug in network meta-analyses. 1
Do not prescribe prostaglandins to patients with active uveitis or history of cystoid macular edema, as their pro-inflammatory mechanism may worsen these conditions. 9
Do not combine two topical beta-blockers, as this provides no additional benefit and increases systemic adverse effects. 6
Preservative-free formulations are preferred when available, particularly for patients with ocular surface disease or those requiring multiple medications. 7, 3