Glaucoma Drops: Stepwise Medication Strategy
Start with target IOP and adherence
Glaucoma pharmacotherapy works best when it is anchored to a clear target intraocular pressure (IOP) and a regimen a patient can actually follow. Most stepwise plans begin with a once-daily medication, then add a second mechanism if the patient does not reach target or if progression is suspected. As therapy escalates, technique (spacing, punctal occlusion, and bottle handling) and side-effect counseling become as important as medication selection.
Prostaglandin analogs as first-line therapy
In the absence of contraindications, prostaglandin analogs (latanoprost, bimatoprost, travoprost, and related agents) are commonly used as first-line therapy for primary open-angle glaucoma and ocular hypertension. They primarily increase uveoscleral outflow and often achieve about 25 to 30% IOP reduction with once-nightly dosing, which supports adherence compared with multi-dose regimens.
Prostaglandin-related options such as latanoprostene bunod include a nitric oxide donating component that can enhance trabecular outflow. These agents may be considered when a patient responds to a prostaglandin but has not reached target IOP on a conventional PGA alone.
Add a second mechanism when needed
If monotherapy does not achieve target IOP, additional classes are introduced stepwise. Selection should consider expected IOP effect, dosing burden, preservative exposure, and systemic contraindications.
- Beta blockers (for example, timolol): Reduce aqueous production and can provide meaningful additional IOP lowering. Because they can be systemically absorbed, non-selective beta blockers are usually avoided in asthma, significant COPD, bradycardia, and certain cardiac conduction disorders.
- Alpha-2 agonists (for example, brimonidine): Lower IOP by suppressing aqueous production and enhancing uveoscleral outflow. Use can be limited by allergic follicular conjunctivitis, fatigue, and dry mouth, especially with long-term use.
- Topical carbonic anhydrase inhibitors (CAIs): Dorzolamide and brinzolamide are useful adjuncts and are often combined with other classes when additional lowering is needed, particularly when systemic CAIs are undesirable.
If two agents are needed, it is often better to add one clearly complementary mechanism and reassess rather than layering multiple drops quickly without confirming response and tolerability.
ROCK inhibitors for trabecular outflow support
Netarsudil is a rho kinase inhibitor that targets the trabecular outflow pathway by modulating the cytoskeleton within the trabecular meshwork and distal outflow system. It can be helpful when a lower target pressure is needed from a relatively low baseline, such as in normal-tension glaucoma, or as an adjunct to prostaglandin therapy. Common limiting adverse effects include conjunctival hyperemia, mild instillation discomfort, and corneal verticillata that is usually asymptomatic but should be documented and monitored.
Fixed combinations and regimen simplification
As the number of bottles increases, adherence and correct spacing of drops become harder. Fixed combinations such as timolol/dorzolamide, timolol/brimonidine, or brinzolamide/brimonidine can simplify dosing by combining two mechanisms in a single bottle. When monotherapy is insufficient, moving to an appropriate fixed combination can reduce complexity and preservative exposure compared with multiple separate bottles.
Systemic screening, technique, and follow-up
Because topical glaucoma medications can be systemically absorbed, review cardiovascular history, pulmonary disease, and current medications before prescribing agents such as beta blockers or alpha-2 agonists. Teach punctal occlusion and proper instillation technique to reduce systemic exposure and improve local efficacy. Regular follow-up remains essential to reassess target IOP, optic nerve status, and visual field stability, and to adjust therapy if progression is suspected.