Related Experiment Video
Updated: Jun 4, 2026
08:51
Intra-cardiac Side-Firing Light Catheter for Monitoring Cellular Metabolism using Transmural Absorbance Spectroscopy of Perfused Mammalian Hearts
Published on: May 12, 2019
Visual loss caused by acute cyanide poisoning: a case report
Fei Chen1, Libin Jiang, Bentao Yang
1Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Sciences Key Lab, Beijing, China.
Clinical Toxicology (Philadelphia, Pa.)
|March 5, 2011
Summary
Acute cyanide poisoning can cause severe visual field defects and decreased pattern visual evoked potential (P100 wave amplitude), suggesting posterior visual pathway damage despite normal MRI scans.
Area of Science:
- Neuroscience
- Toxicology
- Ophthalmology
Background:
- Cyanide is a highly lethal poison.
- Visual changes following acute cyanide poisoning are seldom reported due to low survival rates.
Observation:
- A 30-year-old man experienced bilateral vision loss after inhaling sodium cyanide.
- Standard ophthalmic examinations revealed no abnormalities 5 months post-exposure.
Findings:
- Pattern visual evoked potential showed reduced P100 wave amplitude.
- Humphrey perimetry and AccuMap multifocal visual evoked potentials indicated severe central visual field defects.
- MRI revealed abnormal signal changes in the bilateral putamen.
Implications:
- Clinical presentation and electrophysiological tests suggest a posterior visual pathway lesion.
- This case highlights potential visual pathway damage in cyanide poisoning survivors.
- Further research is needed to understand the long-term visual consequences of cyanide toxicity.
Related Concept Videos
01:26Anticholinesterase Agents: Poisoning and Treatment
Anticholinesterases, also known as cholinesterase inhibitors, work by blocking the breakdown of acetylcholine, leading to its accumulation in the synaptic cleft. This accumulation indirectly enhances both muscarinic and nicotinic actions. These agents are classified as reversible or irreversible based on their mechanism of action.
Irreversible agents form a strong bond with the cholinesterase enzyme, making it inactive. The breakdown of the phosphorylated enzyme is slower than the...
Irreversible agents form a strong bond with the cholinesterase enzyme, making it inactive. The breakdown of the phosphorylated enzyme is slower than the...
01:22Photoreceptors and Visual Pathways
At the molecular level, visual signals trigger transformations in photopigment molecules, resulting in changes in the photoreceptor cell's membrane potential. The photon's energy level is denoted by its wavelength, with each specific wavelength of visible light associated with a distinct color. The spectral range of visible light, classified as electromagnetic radiation, spans from 380 to 720 nm. Electromagnetic radiation wavelengths exceeding 720 nm fall under the infrared category, whereas...
01:26Pharmaceutical Poisoning: Potential Scenarios
Pharmaceutical poisoning can occur through various channels, impacting an estimated 2 million hospitalized patients in the U.S. annually with serious adverse drug responses. These scenarios encompass both therapeutic uses, such as drug toxicity, where even standard dosages can lead to severe central nervous system depression, and non-therapeutic exposures, including accidental ingestion by children, and environmental and occupational exposures.Unintentional poisonings often involve exploratory...
01:26Pharmaceutical Poisoning: Treatment Strategies
Treatment strategies for poisoning are a critical aspect of emergency medicine, focusing on preventing the absorption of toxins and enhancing their elimination. When a poisoning incident occurs, the first response is to halt exposure and decontaminate the patient, particularly through gastrointestinal (GI) methods if the poison was ingested.Gastrointestinal Decontamination Techniques:Activated charcoal is the cornerstone of GI decontamination. It works through adsorption, binding the toxin to...
01:26Acute Coronary Syndrome V: Nursing Management
Nursing Assessment:Nursing management of acute coronary syndrome (ACS) involves taking the patient's history, focusing on primary complaints such as chest pain, dyspnea, and excessive sweating (diaphoresis), as well as other symptoms like back or jaw pain, nausea, vomiting, palpitations, dizziness, and fatigue. The nurse also reviews the patient's history of cardiac events, risk factors such as hypertension, diabetes, smoking, family history, and current medications.In the objective assessment,...
01:29Hepatic Encephalopathy
DefinitionHepatic encephalopathy is a reversible neurologic syndrome that results from advanced liver dysfunction or portosystemic shunting. It leads to disturbances in cognition, behavior, and motor function due to the brain’s exposure to gut-derived toxins that the liver fails to detoxify.EtiologyThis condition develops either in the setting of acute fulminant hepatitis or progressively during chronic liver disease, such as cirrhosis and portal hypertension. Portosystemic shunting—including...