The Endocannabinoid System as a Therapeutic Target in Glaucoma.

“Glaucoma is an irreversible blinding eye disease which produces progressive retinal ganglion cell (RGC) loss. Intraocular pressure (IOP) is currently the only modifiable risk factor, and lowering IOP results in reduced risk of progression of the disorder.

The endocannabinoid system (ECS) has attracted considerable attention as a potential target for the treatment of glaucoma, largely due to the observed IOP lowering effects seen after administration of exogenous cannabinoids.

However, recent evidence has suggested that modulation of the ECS may also be neuroprotective.

This paper will review the use of cannabinoids in glaucoma, presenting pertinent information regarding the pathophysiology of glaucoma and how alterations in cannabinoid signalling may contribute to glaucoma pathology.

Additionally, the mechanisms and potential for the use of cannabinoids and other novel agents that target the endocannabinoid system in the treatment of glaucoma will be discussed.”

http://www.ncbi.nlm.nih.gov/pubmed/26881140

http://www.thctotalhealthcare.com/category/glaucoma-2/

Endogenous and Synthetic Cannabinoids as Therapeutics in Retinal Disease.

“The functional significance of cannabinoids in ocular physiology and disease has been reported some decades ago.

In the early 1970s, subjects who smoked Cannabis sativa developed lower intraocular pressure (IOP). This led to the isolation of phytocannabinoids from this plant and the study of their therapeutic effects in glaucoma.

The main treatment of this disease to date involves the administration of drugs mediating either the decrease of aqueous humour synthesis or the increase of its outflow and thus reduces IOP. However, the reduction of IOP is not sufficient to prevent visual field loss.

Retinal diseases, such as glaucoma and diabetic retinopathy, have been defined as neurodegenerative diseases and characterized by ischemia-induced excitotoxicity and loss of retinal neurons. Therefore, new therapeutic strategies must be applied in order to target retinal cell death, reduction of visual acuity, and blindness.

The aim of the present review is to address the neuroprotective and therapeutic potential of cannabinoids in retinal disease.”

http://www.ncbi.nlm.nih.gov/pubmed/26881135

The Endocannabinoid System in the Retina: From Physiology to Practical and Therapeutic Applications.

“Cannabis is one of the most prevalent drugs used in industrialized countries.

The main effects of Cannabis are mediated by two major exogenouscannabinoids: ∆9-tetrahydroxycannabinol and cannabidiol. They act on specific endocannabinoid receptors, especially types 1 and 2.

Mammals are endowed with a functional cannabinoid system including cannabinoid receptors, ligands, and enzymes.

This endocannabinoid signaling pathway is involved in both physiological and pathophysiological conditions with a main role in the biology of the central nervous system.

As the retina is a part of the central nervous system due to its embryonic origin, we aim at providing the relevance of studying the endocannabinoid system in the retina. Here, we review the distribution of the cannabinoid receptors, ligands, and enzymes in the retina and focus on the role of the cannabinoid system in retinal neurobiology.

This review describes the presence of the cannabinoid system in critical stages of retinal processing and its broad involvement in retinal neurotransmission, neuroplasticity, and neuroprotection.

Accordingly, we support the use of synthetic cannabinoids as new neuroprotective drugs to prevent and treat retinal diseases.

Finally, we argue for the relevance of functional retinal measures in cannabis users to evaluate the impact of cannabis use on human retinal processing.”

http://www.ncbi.nlm.nih.gov/pubmed/26881099

Cannabinoids for treatment of glaucoma.

“The purpose of this article is to review the current status of cannabis in the treatment of glaucoma, including the greater availability of marijuana in the USA.

The pharmacology of marijuana and its effect on intraocular pressure has not changed since the research in the 1970s and 1980s.

Marijuana is an effective ocular hypotensive agent.

However, cardiovascular and neurological effects are observed at the same dose, and may theoretically reduce the beneficial effect of lowering intraocular pressure by reducing ocular blood flow. The clinician must be cognizant of this potential in diagnosis, prognosis, and therapy.”

http://www.ncbi.nlm.nih.gov/pubmed/26840343

Expression and Function of the Endocannabinoid System in the Retina and the Visual Brain.

“Endocannabinoids are important retrograde modulators of synaptic transmission throughout the nervous system.

Cannabinoid receptors are seven transmembrane G-protein coupled receptors favoring Gi/o protein. They are known to play an important role in various processes, including metabolic regulation, craving, pain, anxiety, and immune function.

In the last decade, there has been a growing interest for endocannabinoids in the retina and their role in visual processing.

The purpose of this review is to characterize the expression and physiological functions of the endocannabinoid system in the visual system, from the retina to the primary visual cortex, with a main interest regarding the retina, which is the best-described area in this system so far.

It will show that the endocannabinoid system is widely present in the retina, mostly in the through pathway where it can modulate neurotransmitter release and ion channel activity, although some evidence also indicates possible mechanisms via amacrine, horizontal, and Müller cells.

The presence of multiple endocannabinoid ligands, synthesizing and catabolizing enzymes, and receptors highlights various pharmacological targets for novel therapeutic application to retinal diseases.”

http://www.ncbi.nlm.nih.gov/pubmed/26839718

Seeing over the horizon – targeting the endocannabinoid system for the treatment of ocular disease.

“The observation that marijuana reduces intraocular pressure was made by Hepler and Frank in the 1970s. Since then, there has been a significant body of work investigating cannabinoids for their potential use as therapeutics.

To date, no endocannabinoid system (ECS)-modulating drug has been approved for clinical use in the eye; however, recent advances in our understanding of the ECS, as well as new pharmacological tools, has renewed interest in the development of ocular ECS-based therapeutics.

This review summarizes the current state-of-affairs for the use of ECS-modulating drugs for the treatment of glaucoma and ocular inflammatory and ischemic disease.”

http://www.ncbi.nlm.nih.gov/pubmed/26565550

[CANNABIS AND GLAUCOMA: AN ANCIENT LEGEND OR A NOVEL THERAPEUTIC HORIZON?].

“Glaucoma causes damage to the optic nerve and compromises the visual field. The main risk factor of the disease is the level of the intra-ocular pressure. Therapeutic options include medical and surgical treatment, aimed to lower the intra-ocular pressure.

Consumption of the cannabis plant (Cannabis Satival has been known since ancient times. It can be consumed orally, topically, intra-venous or by inhalation.

The main active ingredient of cannabis is THC (Tetra-Hydro-Cannabinol). One of THC’s reported effects is the reduction of intra-ocular pressure.

Several studies have demonstrated temporary intra-ocular pressure decrease in both healthy subjects and glaucoma patients following topical application or systemic consumption.

Cannabis may be considered as a therapeutic option in glaucoma.”

http://www.ncbi.nlm.nih.gov/pubmed/26281086

Therapeutic potential of cannabis-related drugs.

“In this review, I will consider the dual nature of Cannabis and cannabinoids.

The duality arises from the potential and actuality of cannabinoids in the laboratory and clinic and the ‘abuse’ of Cannabis outside the clinic.

The therapeutic areas currently best associated with exploitation of Cannabis-related medicines include pain, epilepsy, feeding disorders, multiple sclerosis and glaucoma.

As with every other medicinal drug of course, the ‘trick’ will be to maximise the benefit and minimise the cost.

After millennia of proximity and exploitation of the Cannabis plant, we are still playing catch up with an understanding of its potential influence for medicinal benefit.”

http://www.ncbi.nlm.nih.gov/pubmed/26216862

Biomedical benefits of cannabinoids?

“Cannabinoids appear to be of therapeutic value as antiemetics, antispasmodics, analgesics and appetite stimulants and may have potential uses in epilepsy, glaucoma and asthma.

This paper reviews the clinical trials which have been carried out with cannabinoids including Δ⁹-tetrahydrocannabinol (THC) and synthetic cannabinoids such as nabilone and levonantradol, and discusses the advantages and adverse effects of cannabinoids in clinical use.

The place of cannabinoids in modern medicine remains to be properly evaluated, but present evidence suggests that they could be valuable, particularly as adjuvants, for symptom control in a range of conditions for which standard drugs are not fully satisfactory.”

Cannabinoid-induced chemotaxis in bovine corneal epithelial cells.

Cannabinoid CB1 receptors are found in abundance in the vertebrate eye, with most tissue types expressing this receptor. However, the function of CB1 receptors in corneal epithelial cells (CECs) is poorly understood. Interestingly, the corneas of CB1 knockout mice heal more slowly after injury via a mechanism proposed to involve protein kinase B (Akt) activation, chemokinesis, and cell proliferation. The current study examined the role of cannabinoids in CEC migration in greater detail…

In summary, we find that CB1-based signaling machinery is present in bovine cornea and that activation of this system induces chemotaxis.”

http://www.ncbi.nlm.nih.gov/pubmed/26024113

http://medical-dictionary.thefreedictionary.com/chemotaxis