Related Experiment Video

Updated: Jul 4, 2026

Assessment of Vascular Tone Responsiveness using Isolated Mesenteric Arteries with a Focus on Modulation by Perivascular Adipose Tissues
08:41

Assessment of Vascular Tone Responsiveness using Isolated Mesenteric Arteries with a Focus on Modulation by Perivascular Adipose Tissues

Published on: June 3, 2019

The effect of various alpha1-adrenergic receptor antagonists on pupillary dilation

Gul Arikan1, Omer Demir, Aylin Yaman

  • 1Department of Ophthalmology, Dokuz Eylul University, Izmir, Turkey.

Annals of Ophthalmology (Skokie, Ill.)
|June 18, 2008
PubMed

Insights

Systemic alpha1 adrenergic receptor antagonists used for benign prostatic hyperplasia can affect pupil dilation. Preoperative pupil size alone does not reliably predict the risk of intraoperative floppy iris syndrome.

Area of Science:

  • Ophthalmology
  • Pharmacology

Background:

  • Benign prostatic hyperplasia (BPH) is commonly treated with alpha1 adrenergic receptor antagonists.
  • These medications can affect smooth muscle, including the iris dilator muscle.

Purpose of the Study:

  • To prospectively evaluate the impact of systemic alpha1 adrenergic receptor antagonists on pupillary dilation in BPH patients.
  • To determine if preoperative pupillary dilation is a reliable predictor of intraoperative floppy iris syndrome (IFIS).

Main Methods:

  • Prospective evaluation of BPH patients undergoing cataract surgery.
  • Assessment of pupillary dilation in patients using various systemic alpha1 adrenergic receptor antagonists.
  • Correlation of preoperative pupil size with the occurrence of IFIS.

Main Results:

  • Systemic alpha1 adrenergic receptor antagonists significantly affect pupillary dilation.
  • Preoperative pupillary size is not a sufficient indicator for identifying patients at risk for IFIS.
  • The risk of IFIS cannot be solely determined by preoperative pupil size.

Conclusions:

  • Clinicians should be aware of the potential for pupillary abnormalities in BPH patients treated with alpha1 blockers.
  • Further investigation is needed to identify reliable predictors for IFIS in this patient population.
  • Management strategies may need to be adjusted for BPH patients at risk for IFIS.

More Related Videos

Pupillary Response as Assessment of Effective Seizure Induction by Electroconvulsive Therapy04:51

Pupillary Response as Assessment of Effective Seizure Induction by Electroconvulsive Therapy

Published on: April 11, 2019

In vitro Measurements of Tracheal Constriction Using Mice10:20

In vitro Measurements of Tracheal Constriction Using Mice

Published on: June 25, 2012

Related Concept Videos

Adrenergic Antagonists: Pharmacological Actions of ɑ-Receptor Blockers01:22

Adrenergic Antagonists: Pharmacological Actions of ɑ-Receptor Blockers

α-Adrenergic antagonists, known as α-blockers, exert their effects by inhibiting α-adrenoceptors, leading to specific physiological actions. α1-blockers and α2-blockers have distinct pharmacological actions and therapeutic applications.
α1-blockers: These drugs inhibit α1-adrenoceptors on smooth muscle cells, resulting in vasodilation. This vasodilation lowers blood pressure, making α1-blockers valuable in treating hypertension. Additionally, α1-blockers effectively address urinary obstruction...
Direct-Acting Cholinergic Agonists: Pharmacological Actions00:59

Direct-Acting Cholinergic Agonists: Pharmacological Actions

Direct-acting cholinergic agonists exert their pharmacological actions by mimicking the effects of acetylcholine on postsynaptic muscarinic receptors to generate parasympathetic responses. These agents elicit a range of physiological responses, including cardiovascular effects. For example, activation of muscarinic receptors induces bradycardia, decreased cardiac output, reduced peripheral resistance, and consequent hypotension. In the eye, stimulation of M3 receptors leads to smooth muscle...
Adrenergic Agonists: Direct-Acting Agents01:30

Adrenergic Agonists: Direct-Acting Agents

Drugs that mimic the action of endogenous catecholamines like noradrenaline and adrenaline are called adrenergic agonists or sympathomimetics. Based on their mechanism of action, sympathomimetics can be classified as direct-, indirect-, or mixed-acting sympathomimetics. Direct-acting adrenergic agonists activate adrenoceptors without affecting presynaptic neurons, making them independent of neuronal catecholamine-depleting agents like reserpine and guanethidine.
These agents can be classified...
Adrenergic Agonists: Therapeutic Uses01:30

Adrenergic Agonists: Therapeutic Uses

Adrenergic agonists have diverse therapeutic uses across various medical conditions and emergencies.
Emergency and Intensive Care Unit (ICU) applications: Pressor agents increase blood pressure, heart rate, and contractility in shock and organ failure situations. Dopamine can induce vasodilation and stimulate adrenoceptors. Endogenous catecholamines are effective in treating cardiogenic shock. α2-agonists like clonidine can reverse anesthesia-induced hypertension.
Allergies and anaphylaxis:...
Adrenergic Antagonists: Chemistry and Classification of ɑ-Receptor Blockers01:17

Adrenergic Antagonists: Chemistry and Classification of ɑ-Receptor Blockers

Adrenergic antagonists, or sympatholytics, inhibit adrenoceptor activation driven by catecholamines or agonists. Based on their adrenoceptor specificity, adrenergic blockers can be categorized into two primary groups: α-adrenergic blockers (α-blockers) and β-adrenergic blockers (β-blockers). α-blockers interact with α1 and α2 subtypes of α-adrenoceptors.
Nonselective α-blockers: Nonselective α-blockers contain haloalkylamine or imidazoline moieties. Phenoxybenzamine, with a haloalkylamine...
Adrenergic Receptors: ɑ Subtype01:31

Adrenergic Receptors: ɑ Subtype

Adrenoceptors are classified into α and ꞵ classes based on their potencies to catecholamine agonists. α-adrenoceptors show the following order of catecholamine potency:
Adrenaline ≥ Noradrenaline >> Isoprenaline
α-adrenoceptors are further divided into α1 and α2-adrenoceptors.
α1-Adrenoceptors: These receptors are located postsynaptically on the effector organs and cause constriction of smooth muscle mediated by activation of phospholipase C—inositol-1,4,5-trisphosphate...