Antiglaucoma Medications That Increase Optic Nerve Perfusion
Prostaglandin analogues as a class increase mean ocular perfusion pressure, with bimatoprost demonstrating the strongest evidence for improving optic nerve perfusion compared to other antiglaucoma medications. 1
Primary Recommendation: Prostaglandin Analogues
Bimatoprost specifically increases mean ocular perfusion pressure when compared to timolol and provides beneficial ocular perfusion pressure profiles compared to alternative agents. 1, 2 This represents low to moderate quality evidence from systematic reviews examining post-intervention mean ocular perfusion pressure in open-angle glaucoma. 1
Key Prostaglandin Analogues That Improve Perfusion:
- Bimatoprost - strongest evidence for increasing ocular perfusion pressure 1, 2
- Latanoprost - part of prostaglandin class shown to increase perfusion 1
- Travoprost - included in prostaglandin class with perfusion benefits 1
- Tafluprost - prostaglandin analogue with class effect on perfusion 1
Emerging Option: Latanoprostene Bunod
Latanoprostene bunod is a nitric oxide-donating prostaglandin analogue that shows promise in regulating ocular blood flow through its nitric oxide component. 3 The nitric oxide component has demonstrated potential for promoting retinal ganglion cell survival in addition to enhancing aqueous outflow. 3
Medications That Do NOT Increase Optic Nerve Perfusion
Beta-Blockers
Timolol and other beta-blockers do not increase optic nerve head flow. 4 In fact, nighttime dosing of beta-blockers may contribute to visual field progression via nocturnal reduction of systemic blood pressure. 1 Beta-blockers work by reducing aqueous humor production through blockade of sympathetic nerve endings in the ciliary epithelium, without beneficial effects on perfusion. 5
Alpha-2 Agonists
Brimonidine does not reliably increase optic nerve head flow. 4 While brimonidine has been studied for potential neuroprotective effects, the evidence remains inconclusive and of very low certainty. 6 The American Academy of Ophthalmology advises against prescribing brimonidine specifically for neuroprotection given the lack of high-certainty clinical evidence. 6
Carbonic Anhydrase Inhibitors
Brinzolamide and other carbonic anhydrase inhibitors were not shown to increase optic nerve head flow in preliminary studies. 4 These medications work primarily by decreasing aqueous humor production. 1
Clinical Context and Limitations
Autoregulation Considerations
Optic nerve head blood flow autoregulation appears to function in early-stage glaucoma (hypertensive and preperimetric) but fails in advanced perimetric glaucoma. 4 In advanced glaucoma, antiglaucomatous drugs were not able to increase optic nerve head flow, suggesting that perfusion benefits may be limited to earlier disease stages. 4
Evidence Quality
The evidence for prostaglandins improving ocular perfusion is rated as low to moderate quality. 1 However, this represents the strongest available evidence among all antiglaucoma medication classes for improving optic nerve perfusion.
Practical Implementation
When perfusion enhancement is a clinical consideration:
- First choice: Bimatoprost - provides both superior IOP reduction and documented perfusion improvement 1, 2
- Alternative prostaglandins (latanoprost, travoprost, tafluprost) share the class effect on perfusion 1
- Avoid relying on beta-blockers or brimonidine for perfusion benefits, as they lack evidence for improving optic nerve head blood flow 6, 4