Medication Summary
The preferred drugs have the pharmacologic action of aqueous suppression. A beta-antagonist is the common first choice, with subsequent additions of an alpha-agonist and/or a carbonic anhydrase inhibitor, as necessary. Prostaglandin analogs probably have a useful role, but the use of miotic agents is controversial and not routinely recommended. [44]
The goal of therapy is IOP reduction. Medications must often be used long term. IOP should be monitored whenever medications are discontinued or changed, and therapy should be restarted, if necessary.
Beta-agonists
Class Summary
Topical beta-adrenergic receptor antagonists decrease the production of aqueous humor by the ciliary body. Adverse effects are due to systemic absorption of the drug, which causes decreased cardiac output and bronchoconstriction. These agents may cause bronchospasm, bradycardia, heart block, or hypotension. Monitor the patient's pulse rate and blood pressure. Patients may be instructed to perform punctal occlusion after administering the drops. Some patients may have depression or anxiety, and sexual dysfunction may occur or worsen.
Timolol maleate (Timoptic, Timoptic XE) 0.25%, 0.5%
May reduce elevated or normal IOP, with or without glaucoma, by reducing aqueous humor production.
Levobunolol (Betagan, AKBeta) 0.25%, 0.5%
Nonselective beta-adrenergic blocking agent. Lowers IOP by reducing aqueous humor production.
Carteolol ophthalmic (Ocupress)
Blocks beta1- and beta2-receptors. Has mild intrinsic sympathomimetic effects.
Betaxolol ophthalmic (Betoptic)
Selectively blocks beta1-adrenergic receptors. Reduces IOP by reducing aqueous humor production.
Adrenergic agonists
Class Summary
Topical adrenergic agonists (sympathomimetics) decrease aqueous production and reduce resistance to aqueous outflow. Adverse effects include dry mouth and hypersensitivity.
Apraclonidine (Iopidine) 0.5%, 1%
Selective alpha-adrenergic agonist that suppresses aqueous production. Minimal cardiovascular effect.
Brimonidine (Alphagan)
Selective alpha2-receptor agonist. Reduces aqueous humor formation. Possibly increases uveoscleral outflow.
Carbonic anhydrase inhibitors
Class Summary
These drugs reduce secretion of the aqueous humor by inhibiting carbonic anhydrase in the ciliary body. These agents are less effective than many other classes of drugs and have a shorter duration of action. Adverse effects are relatively rare but include superficial punctate keratitis, acidosis, paresthesias, nausea, depression, and lassitude. Corneal decompensation has been reported when this class of drugs is used in patients with corneal endothelial dysfunction.
Dorzolamide (Trusopt)
Used concomitantly with other topical ophthalmic drugs to lower IOP. If > 1 ophthalmic drug used, administer >10 min apart. Reversibly inhibits carbonic anhydrase, reducing hydrogen ion secretion at renal tubule. Increases renal excretion of sodium, potassium bicarbonate, and water to decrease aqueous humor production.
Brinzolamide (Azopt) 1%
Catalyzes reversible reaction involving hydration of carbon dioxide and dehydration of carbonic acid. May use concomitantly with other topical ophthalmic drug products to lower IOP. If >1 topical ophthalmic drug used, administer >10 min apart.
Dorzolamide HCl/timolol maleate (Cosopt)
Dorzolamide is carbonic anhydrase inhibitor that may decrease aqueous humor secretion, decreasing IOP; presumably slows bicarbonate ion formation with subsequent reduction in sodium and fluid transport. Timolol is nonselective beta-adrenergic receptor blocker; decreases IOP by decreasing aqueous humor secretion. Administered together bid may reduce IOP more than either alone, but reduction not as much as that with concomitant dorzolamide tid and timolol bid.
Acetazolamide (Diamox, Diamox Sequels)
Reduces aqueous humor formation by inhibiting enzyme carbonic anhydrase, decreasing IOP.
Methazolamide (Neptazane, GlaucTabs)
Reduces aqueous humor formation by inhibiting carbonic anhydrase, decreasing IOP.
Prostaglandin analogs
Class Summary
These selective agonists act on prostaglandin receptors in the eye to lower IOP by increasing uveoscleral outflow.
Latanoprost (Xalatan)
Decreases IOP by increasing outflow of aqueous humor.
Bimatoprost ophthalmic solution (Lumigan)
Prostamide analog with ocular hypotensive activity. Mimics IOP-lowering activity via the prostamide pathway. Used to reduce IOP in open-angle glaucoma or ocular hypertension.
Travoprost ophthalmic solution (Travatan)
Prostaglandin F2-alpha analog. Selective prostaglandin F2 receptors prostanoid receptor agonist; may reduce IOP by increasing uveoscleral outflow. Used to treat open-angle glaucoma or ocular hypertension.
Unoprostone ophthalmic (Rescula)
Prostaglandin F2-alpha analog. Selective FP prostanoid receptor agonist; may reduce IOP by increasing uveoscleral outflow. Used to treat open-angle glaucoma or ocular hypertension.
-
Irregular widening of the visible ciliary body in a quadrant with angle recession.
-
Angle recession. Note the marked posterior displacement of the iris, with a wide ciliary body band posterior to the scleral spur.
-
Gonioscopic examination many years after blunt trauma in a patient with angle-recession glaucoma. Note the irregular contour of the iris, with loss of detail of angle structures. Classic findings of angle recession may become subtle or be obscured over time.
