CYCLOPLEGICS – INTRODUCTION
Cycloplegia is paralysis of the ciliary muscle of the eye, resulting in a loss of accommodation. Because of the paralysis of the ciliary muscle, the curvature of the lens can no longer be adjusted to focus on nearby objects.
CYCLOPLEGICS – INDICATION
Cyclopentolate hydrochloride ophthalmic solution is used to produce mydriasis and cycloplegia.
Cyclopegic eye drops cause cycloplegia, which is paralysis of the ciliary muscle in the eye.
CYCLOPLEGICS – INFORMATION
Cycloplegics are medications, usually in the form of eye drops, which cause cycloplegia, which is paralysis of the ciliary muscle in the eye. This stops accommodation of the eye, that is focusing for vision at different distances. There are a number of drugs which are cycloplegics including atropine, homatropine, cyclopentolate and tropicamide, all of which differ slightly in potency, onset and duration of action. They are available in most countries by prescription only and trade names may differ from country to country, according to manufacturer.
The mechanism of action of cycloplegics is by their blocking action on the muscarinic receptors in the eye. These receptors are involved in the ocular muscle action so, by blocking them, the cycloplegics prevent the muscles from moving. This not only causes cycloplegia, but also mydriasis, which is dilation of the pupil. The different cycloplegics have different potency with regards to both cycloplegia and mydriasis.
The choice of which of the cycloplegics is used will be made by the doctor, according to the indication for which it is being used. Most commonly they are used to make examination of the eye easy. They may also be used to treat uveitis, a swelling or inflammatory condition of the eye, and to prepare the eye for ophthalmic surgery.