Open‑Angle Glaucoma: Medication Classes, Laser & Surgical Options

Primary open‑angle glaucoma (POAG) management follows a stepwise escalation to achieve target IOP.

Topical Medications (First‑Line)

Prostaglandin analogs (PGAs): Latanoprost, travoprost, tafluprost, bimatoprost, latanoprostene bunod. Best efficacy, once‑nightly, few systemic effects.
Beta‑blockers: Timolol 0.25%/0.5%, betaxolol. Contraindicated in asthma/COPD, bradycardia, heart block.
Alpha‑2 agonists: Brimonidine 0.1%/0.15%. Caution in infants (apnea), elderly (CNS effects).
Carbonic anhydrase inhibitors: Dorzolamide 2%, brinzolamide 1%. Sulfa allergy caution.
Rho kinase inhibitor: Netarsudil 0.02%. Conjunctival hyperemia common.
Fixed combinations: PGA+BB, PGA+CAI, BB+CAI, α2+BB — improve adherence.

Acetazolamide / methazolamide: Systemic CAI. Used short‑term for acute IOP spikes or pre‑op; side effects: paresthesias, metabolic acidosis, kidney stones.

SLT: First‑line alternative to drops or adjunct. Targets trabecular meshwork melanin. Repeatable. No thermal damage.
Argon Laser Trabeculoplasty (ALT): Older, thermal, limited repeatability — largely replaced by SLT.

MIGS: iStent inject, Hydrus, OMNI, GATT, Kahook Dual Blade. Best for mild‑moderate POAG + cataract. Safety > efficacy.
Trabeculectomy: Subconjunctival filtration. Highest IOP reduction. Risks: bleb leak, infection, hypotony, cataract.
Tube Shunts: Ahmed (valved), Baerveldt (non‑valved). For refractory, uveitic, neovascular, post‑trabeculectomy failure.
Cyclodestruction (CPC/ECP): End‑stage, poor visual potential.

Most patients eventually need 2–3 medication classes ± laser ± surgery. The goal: target IOP with minimal side effects and burden.