What are Miotics and mydriatics?

Pupil constriction (miosis) can either be stimulated by contraction of the iris sphincter or by relaxation of the iris dilator. On the other hand, pupil dilation (mydriasis) can either be stimulated by contraction of the iris dilator or by relaxation of the iris sphincter.

What are mydriatics and Cycloplegics?

Cycloplegics/mydriatics are ophthalmic medications that are used to dilate the pupil (mydriasis). Each cycloplegic/mydriatic drug works in a different way to maintain dilation in the pupil for a specified period.

What are Miotics used for?

Miotics (drugs that cause the pupil to contract) improve the outflow of aqueous as part of the treatment of glaucoma and reduce the risk of a posteriorly luxated lens entering the anterior chamber.

What do you mean by mydriasis?

Definition of mydriasis : excessive or prolonged dilatation of the pupil of the eye.

What are the mydriatics?

Mydriatics are a type of medicine that make the pupil of the eye dilate (open up). Mydriatics also tend to relax the focusing muscles of the eye, which means that blurred vision is a common side effect.

Why does Cycloplegics cause mydriasis?

Cycloplegia with accompanying mydriasis (dilation of pupil) is usually due to topical application of muscarinic antagonists such as atropine and cyclopentolate. Belladonna alkaloids are used for testing the error of refraction and examination of eye.

When do we use cycloplegia?

Cycloplegic eye drops are used to temporarily relax the ciliary body, or focusing muscle, of the eyes. When a cycloplegic refraction is performed, the optometrist is trying to find out what the full refractive error is without any influence of the person being tested.

What are possible causes of cycloplegia?

Is mydriasis sympathetic or parasympathetic?

The mechanism of mydriasis depends on the agent being used. It usually involves either a disruption of the parasympathetic nerve supply to the eye (which normally constricts the pupil) or overactivity of the sympathetic nervous system (SNS).

What is the example of miotics?

Miotics are either parasympathomimetic (cholinergic-stimulating) drugs which have a direct muscarinic action, such as pilocarpine and carbachol, or anticholinesterase drugs which block the effect of acetylcholinesterase thus letting acetylcholine produce its effect, such as physostigmine, neostigmine, echothiophate and …