Related Experiment Video
Updated: Mar 18, 2026
07:30
Brain Morphology of Cannabis Users With or Without Psychosis: A Pilot MRI Study
Published on: August 18, 2020
8.0K
Transient Retinal Dysfunctions after Acute Cannabis Use.
Thomas Schwitzer1, Matthieu P Robert, Anne Giersch
1EA 7298, INGRES, Université de Lorraine, Vandœuvre-lès-Nancy, France.
European Addiction Research
|July 5, 2016
Summary
Acute cannabis smoking may impair vision, specifically affecting photoreceptor function. This case study highlights potential neuroretinal dysfunction in heavy cannabis users, warranting further research into cannabis and visual processing.
Area of Science:
- Ophthalmology
- Neuroscience
- Pharmacology
Background:
- Cannabis use is prevalent globally, yet its effects on visual function are not well-understood.
- Clinical studies on cannabis users face significant challenges.
- Systemic lupus erythematosus patients on chloroquine require regular ophthalmic evaluations.
Observation:
- A 47-year-old heavy cannabis user underwent ophthalmic evaluation.
- The evaluation included visual acuity, intraocular pressure, fundoscopy, visual field testing, and electroretinography (ERG).
- Tests were conducted 30 minutes and 5 hours post-cannabis smoking.
Findings:
- A significant decrease (up to 48%) in the a-wave amplitude of the full-field electroretinogram (ERG) was observed 30 minutes after cannabis smoking.
- This reduction in scotopic responses suggests acute cannabis inhalation impacts photoreceptor function.
- Other ophthalmic tests showed consistent results between measurements.
Implications:
- This case suggests acute cannabis use can cause neuroretinal dysfunction.
- Further research is needed to understand cannabis's impact on retinal processing.
- Understanding these effects is crucial, given cannabis's association with driving impairment.
