Mydriasis (Blown Pupil) Definition, Causes, Treatment

Learn all about Mydriasis (Blown Pupil), its definition, causes treatment and pupil dilation. Mydriasis is blown pupil or pupil dilation. Mydriasis could be a symptom of raised intracranial pressure. Generally, Mydriasis also refers to the natural dilation of pupils, for instance in low light conditions or under sympathetic stimulation.

Intracranial pressure can also lead to be Mydriasis. Pupil dilation is thought to be the result of uncal herniation causing mechanical compression of the 3rd cranial nerve. Not all the patients with herniation have blown or dilated pupil. In most people, the pupil of the eye may get smaller or larger if it is narrowed it is constricted and when it gets larger it is called dilated.

Therefore an alternative hypothesis is tested and it is concluded that a decrease in the brain stem blood flow (BBF) is a frequent cause of Mydriasis. It should also occur due to ischemia of brain stem. When a person is experiencing Mydriasis their pupils remain dilated for long periods.

Sometimes dilating pupil drops are allowed by doctors for eye surgery because it gives a better view into an eye. Drops also relieve the pain of some eye diseases like uveitis, an inflammation of uvea in the eye. These drops are called mydriatics. Cycloplegic drops are used to paralyze ciliary muscle of the eye. According to mayo clinic, Cycloplegic drops such as atropine the pupil may stay dilated for two weeks and causes eyes redness, watering of eyes and eyelids may swell. Mydriatics without Cycloplegic may cause irritation, light sensitivity, and blurred vision. A headache and pain in brow can also occur.

Although other causes for Mydriasis are botulism, brain death, aneurysm, serotonin syndrome. It may happen due to an intake of dopram injections. Also, the people having Mydriasis have blurred vision, dryness in eyes, blurred vision, dizziness, conjunctivitis also known as pink eye, hypertension and sometimes of glaring of eyes. Most people with Mydriasis do not complain of any symptom but sometimes complain of a headache but is still unclear if this is a symptom of Mydriasis or another co-existing condition.

Mydriasis Definition, causes, Treatment

Mydriasis excessive or persistent dilation of the pupil that is a symptom of ophthalmic or systemic conditions the ophthalmologist may induce Mydriasis using topical atropine to examine the inner eye.
Two eye conditions cause Mydriasis;

Glaucoma; damage to iris

Inflammation or tears in iris also lead to Mydriasis.

Mydriasis is treated with aid of drugs and eye protection devices. During treatment, patients should use sunglasses or contact lenses.

One major complication of Mydriasis is blindness due to overexposure to sunlight.

Mydriasis Definition

Mydriasis is characterized by a prolonged abnormal dilation of the pupil. The pupil remains dilated or excessively large even in the bright environment. Mydriasis is colloquially known as blown pupil. Mydriasis is known to have a pupil diameter of about 4mm which is more than 33% of the iris. It may lead to an increase of Pupil from 4mm-9mm when it is adapted to the dark environment. This is the disorder in which pupil is dilated for a long time. In this condition, pupil fails to respond to light.

Blown Pupil or Pupil Dilation

The blown pupil is an informal medical term used by physicians to refer to sudden papillary dilation and loss of ability to constrict in response to light. It can signal a stroke, impending brain herniation or other brain catastrophes in patients of intensive care unit. Dilated pupils occur when pupils increase in size. Sometime pupil of one eye dilates and this is called unilateral Mydriasis. Usually, the pupil dilation leads to sleeping problems, night sweats and headache. Sometimes the dilated pupils may be themselves the symptom of a migraine headache.

Dilated Pupil Causes

Dilated pupils are due to the head trauma, malignancy, neurological conditions, poisoning, and death and due to the use of certain drugs. Sometimes unilateral Mydriasis is also caused by brain dysfunction

Dilated pupils can be caused by;

• Autonomic neuropathy
• trauma
• Botulism
• Intracranial hematoma
• Ruptured brain
• Black nightshade poisoning
• Toxic mushroom poisoning
• Aneurysm
• Altered consciousness level
• Coma
• Oxytocin also stimulate pupil dilation
• Use of therapeutic medications such as antihistamine and atropine
• Use of recreational drugs such as marijuana, methamphetamine, amphetamine.
• Use of narcotic and heroin
• Acute angle-closure glaucoma
• Adie’s syndrome
• Depression
• Antipsychotic
• Cocaine
• Cinnarizine
• Serotonin syndrome
• Ocular surgery
• Withdrawing from long term use of a variety of opiates
• Cerebral edema
• Lysergic acid diethylamide (LSD)

Mydriasis Treatment

Mydriasis treatment depends on the condition of which it is caused. Patients are recommended to stay out of direct sunlight and use sunglasses to protect inner part of eyes.

Certain medications which include phenylephrine drops, pilocarpine, steroids, atropine, and scopolamine and atropine-scopolamine combination are used.

Murocol 2 may also be prescribed.

Cyclopentolate ophthalmic, Tropic amide ophthalmic, mydriacyl ophthalmic, cycloglyl ophthalmic, cyclomydril ophthalmic and paremyd ophthalmic may also be used to treat Mydriasis.