What causes mydriasis?

Potential causes of unusual mydriasis include injury to the muscles or nerves of the eye, traumatic brain injury, increased levels of oxytocin, and side effects of certain recreational drugs or prescribed medications. Additionally, there are also certain conditions that may result in mydriasis.

What causes unequal dilated pupils?

A misshapen and/or asymmetrical pupil is usually due to disease of the iris (Figure 1). Common causes for iris-related anisocoria include previous corneal or cataract surgery, posterior synechiae (adhesions to the lens) from previous uveitis, or ocular injury (traumatic mydriasis).

What is the difference between mydriasis induced by adrenergic agents and anticholinergic drugs?

Anticholinergic mydriasis occurs via blockade of parasympathetic muscarinic acetylcholine receptors on the iris sphincter muscle. Adrenergic mydriasis occurs by overstimulation of the α1-receptors of the iris dilator muscle leading to sustained contraction.

What causes bilateral mydriasis?

Other causes which lead to bilateral mydriasis include toxic conditions (atropine intoxication, Parkinson drugs, antidepressants, carbonmonoxide intoxication, cocaine), conditions secondary to morbidities (migraine, schizophrenia, hyperthyroidism, coma) and Parinaud oculoglandular syndrome.

What drugs cause dilated pupils?

Stimulants and psychotropic substances most commonly cause pupil dilation. However, this symptom can result from ingesting alcohol, mescaline, cocaine, ecstasy, LSD, psilocybin, MDMA, amphetamines, cannabis, inhalants, narcotics, hallucinogens, bath salts, ketamine, and SSRI antidepressants.

Does glaucoma cause miosis or mydriasis?

Mydriasis is a consistent sign of glaucoma, and intraocular pressure should be measured in all patients with dilated pupils. The most common cause of glaucoma in critically ill patients is anterior uveitis. Glaucoma is painful and blinding, and steps should be taken immediately to lower intraocular pressure.

What is Holmes Adie syndrome?

Holmes-Adie syndrome (HAS) is a neurological disorder affecting the pupil of the eye and the autonomic nervous system.

Does isoproterenol cause mydriasis?

Antimuscarinics (tropicamide) are mydriatic and cycloplegic; α-sympathomimetic agonists are only mydriatic in the eye. Isoproterenol has negligible effects on the eye.

What are mydriatic drugs?

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.