Cannabinoids and the eye.
Cannabis ranks among the most commonly used psychotropic drugs worldwide. In the context of the global movement towards more widespread legalisation, there is a growing need towards developing a better understanding of the physiological and pathological effects. We provide an overview of the current evidence on the effects of cannabinoids on the eye. Of the identified cannabinoids, Δ9-tetrahydrocannabinol is recognized to be the primary psychotropic compound, and cannabidiol is the predominant non-psychoactive ingredient. Despite demonstrating ocular hypotensive and neuroprotective activity, the use of cannabinoids as a treatment for glaucoma is limited by a large number of potential systemic and ophthalmic side effects. Anterior segment effects of cannabinoids are complex, with preliminary evidence showing decreased corneal endothelial density in chronic cannabinoid users. Experiments in rodents, however, have shown potential promise for the treatment of ocular surface injury via anti-nociceptive and anti-inflammatory effects. Electroretinography studies demonstrating adverse effects on photoreceptor, bipolar, and ganglion cell function suggest links between cannabis and neuroretinal dysfunction. Neuro-ophthalmic associations include ocular motility deficits and decrements in smooth pursuit and saccadic eye movements, although potential therapeutic effects for congenital and acquired nystagmus have been observed.
Keywords: Cannabis; cornea; eyelid; glaucoma; intraocular pressure; marijuana; optic nerve; retina.
Copyright © 2020. Published by Elsevier Inc.
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