Peripheral Anterior Synechia Medication

Updated: Jul 26, 2016
  • Author: Andrew J Tatham, MBChB, FRCOphth, FRCSEd, FEBO; Chief Editor: Hampton Roy, Sr, MD  more...
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Medication Summary

No specific medical management exists pertaining to the treatment of peripheral anterior synechiae (PAS). In general, the treatment of the underlying etiology prevents the formation of peripheral anterior synechiae.


Adrenergic agonists

Class Summary

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

Brimonidine (Alphagan)

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

Apraclonidine (Iopidine)

Reduces elevated, as well as normal, IOP whether or not accompanied by glaucoma. 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 followed in patients receiving topical beta-blocker therapy, and punctal occlusion may 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

Contract the ciliary muscle, tightening the TM and allowing increased outflow of the aqueous. Miosis results from action of these drugs on 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.


Prostaglandin analogs

Class Summary

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

Latanoprost (Xalatan)

May decrease IOP by increasing outflow of aqueous humor.



Class Summary

Increase outflow of aqueous humor through the TM and possibly through uveoscleral outflow pathway, probably by a beta2-agonist action. Also may decrease aqueous production with long-term use. Up to one third of patients will not respond to these drugs.

Epinephrine (Epifrin, Glaucon) or Dipivefrin (AKPro, Propine)

Epinephrine lowers IOP by increasing outflow and reducing production of aqueous humor. Used as adjunct to miotic or beta-blocker therapy. Combination of miotic and sympathomimetic has additive effects in lowering IOP.

Dipivefrin is converted to epinephrine in eye by enzymatic hydrolysis. Appears to act by decreasing aqueous production and enhancing outflow facility. Has same therapeutic effect as epinephrine with fewer local and systemic adverse effects. May be used as an initial therapy or as an adjunct with other antiglaucoma agents for the control of IOP.



Class Summary

Can relax any ciliary muscle spasm that can cause a deep aching pain and photophobia.

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 delay of surgery desired to lower 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.

Dorzolamide HCl/ timolol maleate (Cosopt)

Carbonic anhydrase inhibitor that may decrease aqueous humor secretion, causing a decrease in IOP. Presumably slows bicarbonate ion formation with subsequent reduction in sodium and fluid transport.

Timolol is nonselective beta-adrenergic receptor blocker that decreases IOP by decreasing aqueous humor secretion and may slightly increase outflow facility. Both agents administered together bid may result in additional IOP reduction compared with either component administered alone, but reduction is not as much as when dorzolamide tid and timolol bid are administered concomitantly



Class Summary

Reduces intraocular inflammation.

Prednisolone ophthalmic (Pred Forte)

Treats acute inflammations following eye surgery or other types of insults to eye. Decreases inflammation by suppressing migration of polymorphonuclear leukocytes and reversing increased capillary permeability. In cases of bacterial infections, concomitant use of anti-infective agents is mandatory; if signs and symptoms do not improve after 2 days, reevaluate patient. Dosing may be reduced, but advise patients not to discontinue therapy prematurely.