Cannabis and disorders and diseases of the organ of vision

Eye diseases directly linked to oxidative stress include retinal diseases such as glaucoma, uveitis, macular degeneration and diabetic retinopathy.

Oxidative stress occurs when the human body induces an active inflammatory response to compensate for damage from injury or infection by activating microglial cells and releasing macrophages.

However, activation of microglial cells and macrophages is also associated with the release of glutamate, reactive oxygen compounds (ROS), nitric oxide (NO) and tumor necrosis factor (TNF), causing inflammation, vascular destruction and biodegradation. Metabolic syndromes have a negative impact on the health of the visual system, increasing the incidence of age-dependent cataracts, glaucoma, maculopathy and diabetic retinopathy. 

Recent research on CBD highlights its properties of blocking the oxidative stress response associated with the activation of microglial cells, reducing damage associated with inflammatory responses. Since the balanced endocannabinoid system is directly related to metabolic health, therapeutic treatment with phytocannabinoids is suggested to prevent the occurrence of certain disorders of the organ of vision.

Glaucoma

Glaucoma means a number of visual disorders associated with an imbalance of intraocular pressure, as well as associated loss of retinal ganglion cells, nerve damage and loss of vision leading to possible blindness. Research indicates that the release of excess glutamate, which is an important neurotransmitter that occurs properly in retinal ganglion cells, causes ischemic toxicity and cell death.

CBD shows promising results as an intoxicating antioxidant by reducing the production of reactive oxygen compounds (ROS). In these studies, CBD appears to protect against glutamate-derived retinal trauma by preventing the formation of lipid peroxides, nitrite and nitrate compounds, and nitrotyrosine, which are the physiological basis for the development of glaucoma.

Moreover, since the final phase of glaucoma development ultimately leading to progressive vision loss is due to the selective death of retinal ganglion cells due to apoptosis, therapeutic benefits could be achieved through the use of substances that prevent apoptosis and retinal ganglion cell death.

Recent studies have documented the neuroprotective properties of cannabinoids in glaucoma therapy. The effectiveness of repetitive doses seems to reduce intraocular pressure and effectively slow down neurodegenerative and apoptotic processes. The presented results also indicate a possible therapeutic use of CBD in the treatment of glaucoma.

Uveitis

Uveitis includes a group of inflammatory diseases of the organ of vision, accompanied by swelling and tissue destruction leading to loss of vision or blindness. As the disease occupies the uveal membrane, other physiological components such as the lenses, retina, optic nerve and vitreous body are also damaged.

Some studies have shown that uveitis (associated with rheumatological and infectious diseases), indirect uveitis (associated with sarcoidosis and multiple sclerosis), posterior uveitis (associated with choroiditis and infectious diseases), and diffuse uveitis (associated with Behcet's disease) appear to respond positively to the anti-inflammatory effects of CBD.  has shown neuroprotective properties against uveitis by blocking oxidative stress and reducing the destructive effects of endotoxins.  These results may suggest the use of CBD in preventing uveal inflammation associated with autoimmune and infectious diseases.

Macular degeneration

Activation of retinal microglia increases tissue damage and macular degeneration caused by inflammatory disorders. Some studies have shown that CBD could provide effective neuroprotective and anti-inflammatory effects, suggesting possible future use in the prevention and therapy of macular degeneration.

Diabetic retinopathy

Diabetic retinopathy is associated with the destruction of the blood-retinal barrier and the process of dying of retinal ganglion cells, which culminates in the loss of vision. Dysregulation of glucose metabolism, which is characteristic of diabetes, increases hyperpermeability in the retina, increasing susceptibility to retinal injuries caused by reactive oxygen compounds (ROS) and nitrogen stress.

In the case of diabetes, studies indicate an important hereditary factor, but are more likely to be associated with idiopathic autoimmune clinical endocannabinoid deficiency as a result of common, hard-to-adapt lifestyle factors.  Diabetes is an acquired disease, often associated with unhealthy diets and obesity, which contribute to the development of the disease.

The endocannabinoid system is present in the retina, while CBD has been shown to reduce oxidative and nitrogen stress, inflammation, cell death, and vascular hypertransmeability in diabetic retinas.

The use of CBD in diabetes could have a preventive effect leading to the reduction of inflammation and the provision of neuroprotection, which is important in preventing the occurrence of diabetic retinopathy.