Mechanism of action, types, and comparative effects of prostaglandin (PG)-based glaucoma eye drops

👁 What Are Prostaglandin Analogues (PG)?

PG analogues are the most commonly used first-line therapy for
primary open-angle glaucoma (POAG) and normal-tension glaucoma (NTG).

✅ Mechanism of Action

• Binds to FP receptors in the ciliary muscle
  → Relaxes tissue & remodels ECM
  → Increases uveoscleral outflow
  → Lowers intraocular pressure (IOP)

---

💊 Common PG Drugs

Drug NameKey Features

Bimatoprost	Boosts both uveoscleral & trabecular flow
Latanoprost	Widely used; requires refrigeration
Travoprost	Stable efficacy, two strengths
Tafluprost	Preservative-free, single-dose form
Unoprostone	DHA derivative, milder effect

 

 

---

📊 3-Month IOP Reduction (vs. Placebo)

DrugMean IOP Drop (mmHg)

Bimatoprost	-5.61
Latanoprost	-4.85
Travoprost	-4.83
Tafluprost	-4.37
Unoprostone	-1.91

✅ PG analogues outperform most other drug classes in lowering IOP
→ Widely used as first-line glaucoma treatment

---

✅ Summary

• PG drops increase outflow rather than reduce production
• Excellent efficacy with once-daily dosing
• Bimatoprost shows the strongest IOP reduction

📌 Next post: Side effects of PG eye drops