Peripheral Anterior Synechia Medication

Updated: Mar 19, 2021
  • Author: Maria Hannah Pia U de Guzman, MD, DPBO, FPAO; Chief Editor: Hampton Roy, Sr, MD  more...
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Medication Summary

No specific medication that can treat peripheral anterior synechiae (PAS) is available. Some medications may act on the underlying etiology to prevent the formation or progression of PAS. Most medications are only capable of treating the main sequela of PAS, which is elevation of intraocular pressure (IOP).


Adrenergic agonists

Class Summary

Topical adrenergic agonists, or sympathomimetics, decrease aqueous production and reduce resistance to aqueous outflow. Adverse effects include dry mouth and allergic reactions.

Brimonidine (Alphagan)

Selective alpha2-receptor that reduces aqueous humor formation and increases uveoscleral outflow.

Apraclonidine (Iopidine)

Reduces intraocular pressure. A relatively selective alpha-adrenergic agonist that does not have significant local anesthetic activity. Has minimal cardiovascular effects.



Class Summary

Topical beta-adrenergic receptor antagonists decrease aqueous humor production by the ciliary body. Adverse effects of beta-blockers are due to systemic absorption of the drug and include decreased cardiac output and bronchial constriction. In susceptible patients, this may cause bronchospasm, bradycardia, heart block, or hypotension. Pulse rate and blood pressure should be monitored in patients receiving topical beta-blocker therapy, and punctal occlusion may need to be performed after administration of the drops.

Levobunolol (AKBeta, Betagan)

Nonselective beta-adrenergic blocking agent that lowers IOP by reducing aqueous humor production and possibly increases outflow of aqueous humor.

Betaxolol ophthalmic (Betoptic, Betoptic S)

Selectively blocks beta1-adrenergic receptors with little or no effect on beta2-receptors. Reduces IOP by reducing production of aqueous humor.

Timolol maleate (Timoptic, Timoptic XE, Blocadren)

May reduce elevated and normal IOP, with or without glaucoma, by reducing production of aqueous humor or by outflow.


Miotic agents (parasympathomimetics)

Class Summary

Causes contraction of the ciliary muscle which tightens the trabecular meshwork and allows increased outflow of aqueous. Miosis results from action of these drugs on the pupillary sphincter. Adverse effects include brow ache, induced myopia, and decreased vision in low light.

Pilocarpine (Akarpine, Adsorbocarpine, Ocusert Pilo-40, Pilagan, Pilocar)

Directly stimulates cholinergic receptors in the eye, decreasing resistance to aqueous humor outflow.

Instillation frequency and concentration are determined by patients' response. Individuals with heavily pigmented irides may require higher strengths.

If other glaucoma medications also are being used, at bedtime, use gtt at least 5 min before gel.

Patients may be maintained on pilocarpine as long as IOP is controlled and there is no deterioration in visual fields. May use alone or in combination with other miotics, beta-adrenergic blocking agents, epinephrine, carbonic anhydrase inhibitors, or hyperosmotic agents to decrease IOP.


Antiglaucoma, Prostaglandin Agonists

Class Summary

Increase uveoscleral outflow of aqueous humor. One mechanism of action may be through induction of metalloproteinases in ciliary body, which breaks down extracellular matrix, thereby reducing resistance to outflow through the ciliary body.

Latanoprost (Xalatan, Xelpros)

Tafluprost (Zioptan)

Travoprost ophthalmic (Travatan, Travatan Z)

Bimatoprost (Latisse, Lumigan)

Latanoprostene bunod ophthalmic (Vyzulta)



Class Summary

Causes pupil dilation which may help break or prevent posterior synechiae formation. Causes relaxation of the ciliary muscle which can deepen the anterior chamber.

Atropine IV/IM (Atropisol, Atropair, Isopto)

Acts at parasympathetic sites in smooth muscle to block response of sphincter muscle of iris and muscle of ciliary body to acetylcholine, causing mydriasis and cycloplegia. Phenylephrine (2.5% or 10% solution) concurrently with atropine may prevent formation of synechiae by producing wide dilation of pupil.


Carbonic anhydrase inhibitors

Class Summary

Reduce secretion of aqueous humor by inhibiting carbonic anhydrase in the ciliary body. In acute angle-closure glaucoma, carbonic anhydrase inhibitors may be given systemically, but they are used topically in refractory open-angle glaucoma patients. Topical formulations are less effective, and their duration of action is shorter than many other classes of drugs. Adverse effects of topical carbonic anhydrase inhibitors are relatively rare, but they include superficial punctate keratitis, acidosis, paresthesias, nausea, depression, and lassitude.

Acetazolamide (Diamox, Diamox Sequels)

Inhibits enzyme carbonic anhydrase, reducing rate of aqueous humor formation which, in turn, reduces IOP. Used for adjunctive treatment of chronic simple (open-angle) glaucoma and secondary glaucoma and preoperatively in acute angle-closure glaucoma when there is a delay of the surgery intended to lower the IOP.

Methazolamide (Neptazane)

Reduces aqueous humor formation by inhibiting enzyme carbonic anhydrase, which results in decreased IOP.

Dorzolamide (Trusopt, Cosopt)

Used concomitantly with other topical ophthalmic drug products to lower IOP. If more than one ophthalmic drug is being used, administer the drugs at least 10 min apart. Reversibly inhibits carbonic anhydrase, reducing hydrogen ion secretion at renal tubule and increasing renal excretion of sodium, potassium bicarbonate, and water to decrease production of aqueous humor.

Brinzolamide (Azopt)

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 more than one topical ophthalmic drug is being used, administer drugs at least 10 min apart.


Ophthalmics, Other

Netarsudil ophthalmic (Rhopressa)

Thought to lower intraocular pressure by increasing outflow through the trabecular meshwork.