## First-Line Adjunctive Agent in Open-Angle Glaucoma **Key Point:** Prostaglandin analogues (latanoprost, travoprost, bimatoprost) are the most potent IOP-lowering agents and are the preferred second-line addition to beta-blockers in open-angle glaucoma. ### Mechanism of Action Prostaglandin analogues increase uveoscleral (unconventional) outflow of aqueous humour, achieving IOP reduction of 25–35% — superior to other drug classes. ### Rationale for Addition to Beta-Blocker Latanoprost works via a different mechanism than timolol (prostaglandin F receptor agonism vs. β-adrenergic blockade), providing **additive IOP reduction** without redundancy. The combination is synergistic and is standard practice in progressive glaucoma. ### Comparative Efficacy Table | Agent Class | IOP Reduction | Mechanism | Frequency | Notes | | --- | --- | --- | --- | --- | | **Prostaglandin analogues** | 25–35% | ↑ Uveoscleral outflow | Once daily (PM) | **First-line adjunct** | | Beta-blockers | 20–25% | ↓ Aqueous production | Twice daily | Already on therapy | | Carbonic anhydrase inhibitors | 15–20% | ↓ Aqueous production | Variable | Reserved for acute/refractory cases | | Alpha-2 agonists | 15–20% | ↓ Production, ↑ uveoscleral outflow | Twice daily | Alternative adjunct | **High-Yield:** Prostaglandin analogues are the **most potent topical agents** and are universally recommended as second-line therapy in progressive open-angle glaucoma. **Clinical Pearl:** Latanoprost is typically dosed in the evening (PM) because nocturnal IOP peaks are a major driver of glaucomatous damage; evening dosing maximizes neuroprotection. **Tip:** In NEET PG, when a patient on a beta-blocker has progressive glaucoma, the next step is almost always a prostaglandin analogue — this is the standard escalation pathway.
Sign up free to access AI-powered MCQ practice with detailed explanations and adaptive learning.