title: Transient Retinal Dysfunctions after Acute Cannabis Use.
abstract: Although cannabis is very widespread worldwide, the impact of cannabis on visual function remains poorly understood. This is partly due to numerous difficulties met in developing clinical studies in cannabis users. Here, we report the first documented case of neuroretinal dysfunction after acute cannabis smoking. This observation was favored by the need of an annual ophthalmic evaluation in the context of a chloroquine intake for a systemic lupus erythematosus in a 47-year-old heavy cannabis user. A complete ophthalmic evaluation including visual acuity tests, intraocular pressure, fundoscopic examination, automated 10° central visual field, full-field electroretinogram (ERG) and multifocal ERG was performed twice - 30 min and 5 h after cannabis smoking. A strong decrease (up to 48%) in the a-wave amplitude of the full-field ERG was measured 30 min after cannabis smoking for all scotopic responses compared with the responses 5 h after smoking. Other tests showed reproducible results between the 2 series of measurements. This clinical case suggests that acute inhalation of cannabis affects the photoreceptors functioning. This rare situation suggests further investigations are required on the impact of cannabis on retinal processing, especially since cannabis has been incriminated in car injuries.
authors.affiliation: EA 7298, INGRES, Université de Lorraine, Vandœuvre-lès-Nancy, France.
authors.forename: Thomas
authors.initials: T
authors.lastname: Schwitzer
authors.forename: Matthieu P
authors.initials: MP
authors.lastname: Robert
authors.forename: Anne
authors.initials: A
authors.lastname: Giersch
authors.forename: Karine
authors.initials: K
authors.lastname: Angioi-Duprez
authors.forename: Isabelle
authors.initials: I
authors.lastname: Ingster-Moati
authors.forename: Amandine
authors.initials: A
authors.lastname: Pon-Monnier
authors.forename: Raymund
authors.initials: R
authors.lastname: Schwan
authors.forename: Vincent
authors.initials: V
authors.lastname: Laprevote
mesh_terms: D002188:Cannabis; D004596:Electroretinography / Q000187:drug effects* / Q000379:methods; D006801:Humans; D008297:Male; D008385:Marijuana Smoking / Q000009:adverse effects*; D008875:Middle Aged; D012160:Retina / Q000187:drug effects* / Q000502:physiology; D013997:Time Factors; D015357:Vision Disparity / Q000187:drug effects* / Q000502:physiology; D014792:Visual Acuity / Q000187:drug effects / Q000502:physiology