From the Guidelines
Dilated pupils can be caused by various factors, including medications, eye conditions, and neurological issues, and patients with primary angle-closure disease should be warned that certain medicines, such as over-the-counter decongestants and anticholinergic properties, could cause pupil dilation and induce acute angle-closure glaucoma (AACC) 1.
Causes of Dilated Pupils
- Medications: antihistamines, decongestants, antidepressants, and eye drops used during eye exams (mydriatics) can cause pupil dilation 1
- Eye conditions: angle-closure glaucoma may present with a dilated pupil 1
- Neurological issues: head injuries, brain tumors, increased intracranial pressure, seizures, and stroke can cause dilated pupils
- Recreational drugs: cocaine, amphetamines, LSD, and MDMA can also dilate pupils
Warning for Patients with Primary Angle-Closure Disease
Patients with primary angle-closure disease should be warned about the risks of AACC and the potential for certain medicines to cause pupil dilation and induce AACC 1
Physiological Explanation
Pupil dilation occurs when the iris dilator muscle contracts or the iris sphincter muscle relaxes, controlled by the sympathetic and parasympathetic nervous systems respectively 1
Importance of Evaluation
While often harmless, persistently dilated pupils or sudden changes in pupil size should be evaluated by a healthcare provider, especially when accompanied by symptoms like headache, vision changes, or confusion, as they may indicate a serious underlying condition requiring prompt medical attention 1
From the Research
Causes of Dilated Pupils
- Dilated pupils can be caused by various factors, including certain medications, medical conditions, and substances.
- Mydriatics, such as tropicamide, can cause dilated pupils 2.
- Pilocarpine, a medication used to treat glaucoma, can also affect pupil size, but its use in reversing mydriasis may not be helpful and may possibly be harmful 2.
- Certain medical conditions, such as epilepsy, can also cause dilated pupils, and the use of acetylcholine precursors may have variable effects on seizure-experienced animals 3.
- The use of selective serotonin reuptake inhibitors (SSRIs) has been associated with an increased risk of hemorrhagic stroke, which can cause dilated pupils 4, 5.
- Traumatic brain injury (TBI) and the use of certain antidepressants, such as SSRIs, may also increase the risk of stroke and dilated pupils 5.
Related Medical Conditions
- Epilepsy: Pilocarpine-induced status epilepticus can cause neuronal damage and dilated pupils 6.
- Glaucoma: Pilocarpine is used to treat glaucoma, but its use in reversing mydriasis may not be helpful and may possibly be harmful 2.
- Traumatic brain injury (TBI): TBI and the use of certain antidepressants, such as SSRIs, may increase the risk of stroke and dilated pupils 5.
- Stroke: The use of SSRIs has been associated with an increased risk of hemorrhagic stroke, which can cause dilated pupils 4, 5.