Apraclonidine also known as Iopidine, is a sympathomimetic used in glaucoma

Glaucoma

Glaucoma is an eye disorder in which the optic nerve suffers damage, permanently damaging vision in the affected eye and progressing to complete blindness if untreated. It is often, but not always, associated with increased pressure of the fluid in the eye...

 therapy. It is an α₂-adrenergic

Adrenergic receptor

The adrenergic receptors are a class of metabotropic G protein-coupled receptors that are targets of the catecholamines, especially noradrenaline and adrenaline ....

 agonist

Agonist

An agonist is a chemical that binds to a receptor of a cell and triggers a response by that cell. Agonists often mimic the action of a naturally occurring substance...

 and a weak alpha-1 adrenergic receptor agonist.

Apraclonidine is administered at a concentration of 1% for the prevention and treatment of postsurgical intraocular

Human eye

The human eye is an organ which reacts to light for several purposes. As a conscious sense organ, the eye allows vision. Rod and cone cells in the retina allow conscious light perception and vision including color differentiation and the perception of depth...

 pressure elevation and 0.5% for short-term adjunctive therapy in patients on maximally tolerated medical therapy who require additional redirection of intraocular pressure. One drop is usually added one hour prior to laser eye surgery

Eye surgery

Eye surgery, also known as orogolomistician surgery or ocular surgery, is surgery performed on the eye or its adnexa, typically by an ophthalmologist.-Preparation and precautions:...

and another drop is given after the procedure is complete.

Clinical uses

Apraclonidine is indicated for the short-term adjunctive treatment of patients on maximally tolerated medical therapy who require additional reduction. Patients on maximally tolerated medical therapy who are treated with apraclonidine to delay surgery should have frequent followup examinations and treatment should be discontinued if the intraocular pressure rises significantly.

Apraclonidine may be useful in the diagnosis of Horner's syndrome. In Horner's syndrome, the sympathetic innervation to the pupillary dilator muscle is lost. The affected pupil is thus miotic and the pupillary dilator responds to denervation by increasing alpha-1 receptors. Apraclonidine is useful in this case due to its weak alpha-1 adrenergic properties. When applied to the a denervated (and thus hyper-sensitive) pupillary dilator muscle, a super-normal dilatory response is generated in which the pupil dilates to a degree greater than that which would be seen in a non-denervated muscle. This causes the reversal of anisicoria that is characteristic of Horner's.

External links

• Iopidine prescribing information (from the FDA website)
• Simple information on Apraclonidine