Can CBD Oil Help with Eye Inflammation?

Many individuals wonder whether CBD oil can help with eye inflammation. This article explains everything concerning CBD oil and inflammation, including corneal inflammation and pain, endotoxin-induced inflammation, excitotoxicity, diabetic retinopathy, and intraocular pressure.

CBD is among the many cannabinoids found in the cannabis sativa plant. It does not contain psychoactive properties, therefore, it cannot make individuals high or change their state of mind when consumed. CBD oil is extracted from the hemp plant and combined with hemp seed oil and coconut oil. It comes from the cannabis sativa plant and cannabis indica. CBD has gained much attention due to its medical benefits for various diseases. The lack of psychoactive properties in the CBD indicates the power for medical drug development. Some studies have discovered the medical benefits of CBD in the eye. CBD has neuroprotective, anti-inflammatory, and antioxidant properties.

CBD in Pharmaceuticals

CBD comprising drugs are accepted for medicinal consumption in the USA and some other states. The drugs vary in their indicated use and formulation. According to Rubin (2018), Epidiolex is a form of CBD oil accepted by the FDA for treating Dravet syndrome and Lennox. CBD has several potential medical applications for various illnesses through various processes and targets. The claim that CBD has powerful healing effects is supported by preliminary research, scant clinical evidence, and continuing human being scientific research. CBD shows potential as a healing agent in neurological, cardiovascular, and neuropsychiatric diseases.

Corneal Inflammation and Pain

The cornea is a delicate, avascular tissue that receives sensory nerve innervation. Corneal injury brought on by surgery, an infection, or trauma can progress to corneal neuropathic discomfort, categorized by inflammation, hyperalgesia, and continuous severe pain. The inflammatory rejoinder to corneal injury results in the recruitment of leukocytes, creation of pro-inflammatory, and release of pain, making neovascularization in the cornea. CBD oil has anti-inflammatory effects in patients affected by corneal. The patients who used CBD reported reduced pain, which indicated CBD has potential healing for corneal inflammation and pain.

Endotoxin-induced Inflammation

According to Fischer et al. (2010), there are different glial cells, including microglia, muller cells, and astrocytes. The microglial plays a crucial function in retinal homeostasis. They persuade the discharge of pro-inflammatory cytokines when they are activated. However, they contribute to some diseases like retinal degeneration and pathology due to prolonged activation. Adenosine prevents the expression of pro-inflammatory cytokine-like. CBD prevents equilibrative nucleoside transporter and reduces pro-inflammatory cytokine expression. As a result of CBD-activated reduction of adenosine consumption, the impact of CBD is predominantly facilitated through stimulation of the A2A receptor, the most common adenosine receptor in patients. These findings imply that CBD might be an effective anti-inflammatory treatment for retinal injury brought on by endotoxins.

Excitotoxicity

It is indicated in glaucoma as an outcome of excitatory neurotransmitter glutamate's high levels in the retina. According to Yuste et al. (2015), the excitotoxicity process involves the accumulation of superoxide and the activation of nitric oxide. CBD reduces the quantity of apoptosis, prevents neurotoxicity, and reduces the levels of peroxynitrite. However, CBD neuroprotective is reliant on obstruction of formation of nitrotyrosine. CBD's neuroprotective effect and retinal antioxidant may help treat ocular conditions like glaucoma.

Diabetic Retinopathy

Diabetic retinopathy is a significant contributor to visual loss. One of the key factors influencing the evolution of diabetic retinopathy is oxidative stress, which is brought about by responsive oxygen types. Since the retina is the most metabolically lively tissue in the individual's body and is easily harmed by diabetes, it is especially sensitive to responsive oxygen types. Such processes may lead to the death of ganglion cells, loss of vision, and inner retina. Diabetic retinopathy has inflammation properties. Research indicates that ICAM-1 and VEGF control oxidative stress and pro-inflammatory pathways that activate p38 MAP kinase. One report evaluated the healing potential of CBD in a streptozotocin-persuaded diabetic mice replica by estimating proinflammation cytokines and oxidative stress. CBD reduced reactive types of oxygen, inhibited activation of p38 MAP kinase, and suppressed ICAM-1 and VEGF expression. The results proposed that CBD is a potential healing agent for diabetic retinopathy, having the ability to protect against retinal neuronal death of cells, inflammation, and conservation of the blood-retinal blockade.

Intraocular Pressure

Many patients suffer from glaucoma, the main source of permanent blindness, with no treatment. IOP-lowering medications improve aqueous humor drainage through the uveoscleral route and reduce concentrated humor generation in the ciliary body. Novel treatments are required to reduce IOP and stop further ocular nerve injury and loss of vision caused by glaucoma in individuals who do not respond to the medicines mentioned above or drug mixtures or those who have grown tolerant to the present therapies. According to Jones & Vlachou (2020), CBD meaningfully reduced IOP. However, the research does not conclude whether CBD decreases, increases, or results in no change to IOP.

Molecular Mechanism and Target for CBD-Induced Ocular Effects

CBD has many potential targets, including transient receptor potential (TRP) channels, nuclear receptors, ligand-gated ion channels, enzymes, G protein-coupled receptors, and many more. The eye expresses many of these CBD targets. The effects of CBD on these chemical targets in the eye are the main topic of discussion in this section. It's crucial to note that systemic CBD administration could produce CBD metabolites with molecular processes distinct from CBD.

GPR18 and CB1

CBD has been demonstrated to be an undesirable allosteric modulator of CB1. The Corneal, ciliary and trabecular meshwork in the anterior of the eye and the retina in the back express CB1. GPR18 is identified as a reputed cannabinoid receptor and activated by N-arachidoyl glycine. Recently one paper has stated the effect of CBD on GPR18 and CB1.

Challenges of Consuming CBD As an Ocular Healing Agent

Applications of CBD as an eye therapeutic agent face several obstacles, including short time, difficulty in topical delivery, and poor bioavailability. The side effects of CBD include dry mouth, nausea, reduced appetite, drowsiness, and gastrointestinal issues.

Conclusion

Recently, CBD has been preclinically studied for its healing potential in diabetic retinopathy, glaucoma, and corneal damage. Considering its antioxidant, anti-inflammatory, and neuroprotective qualities, one can discover the probability of CBD in treating some other ocular conditions. Clarifying CBD in the eye action mechanism is crucial. There are several different molecular goals for CBD in the eye, as this article has demonstrated. For CBD to be used effectively and safely as an ophthalmic therapeutic agent, it is imperative to understand which goals are accountable for its beneficial and undesirable effects.

References

Fischer, A. J., Scott, M. A., Zelinka, C., & Sherwood, P. (2010). A novel type of glial cell in the retina is stimulated by insulin‐like growth factor 1 and may exacerbate damage to neurons and Müller glia. Glia, 58(6), 633-649.

Jones, É., & Vlachou, S. (2020). A critical review of the role of the cannabinoid compounds Δ9-tetrahydrocannabinol (Δ9-THC) and cannabidiol (CBD) and their combination in multiple sclerosis treatment. Molecules, 25(21), 4930.

Rubin, R. (2018). The path to the first FDA-approved cannabis-derived treatment and what comes next. Jama, 320(12), 1227-1229.

Yuste, J. E., Tarragon, E., Campuzano, C. M., & Ros-Bernal, F. (2015). Implications of glial nitric oxide in neurodegenerative diseases. Frontiers in cellular neuroscience, 9, 322.