Treating Glaucoma: Medical Marijuana, Cannabis

"USA Approved" meds may reduce IOP (intraocular pressure) but sometimes not enough, and furthermore reducing IOP does not always stop or even slow the progress of glaucoma toward blindness.

NOTES: You don’t have to smoke cannabis- vaporizer, tincture, suppository and eating are viable options. (I am not sure if eating cannabis works for glaucoma). Unlike alcohol, caffeine, and cigarettes, cannabis is not addictive. Cannabis’s psycotic effect or tachycardia can be greatly reduced or eliminated if dosage levels are gradually increased Over time cannabis’s medicinal value may attenuate for some conditions or people. Simply cease use and return to cannabis at a later date. Nobody has ever died from Cannabis use.

1) Canasol (a prescription drug made with cannabis) is approved to treat glaucoma in some other countries.

2) Neuroprotector and antioxidant effect of cannabis

a) Neuroprotective Effect of(-)Delta9-Tetrahydrocannabinol and Cannabidiol in N-Methyl-D-Aspartate-Induced Retinal Neurotoxicity: Involvement of Peroxynitrite — El-Remessy et al. 163 (5): 2003 American Journal of Pathology.
Azza B. El-Remessy, Ibrahim E. Khalil, Suraporn Matragoon, Gamal Abou-Mohamed, Nai-Jer Tsai, Penny Roon, Ruth B. Caldwell, Robert W. Caldwell, Keith Green and Gregory I. Liou. From the Departments of Pharmacology and Toxicology, Ophthalmology, and Cellular Biology and Anatomy, and the Vascular Biology Center, Medical College of Georgia, Augusta, Georgia.
In glaucoma, the increased release of glutamate is the major cause of retinal ganglion cell death. Cannabinoids have been demonstrated to protect neuron cultures from glutamate-induced death. In this study, we test the hypothesis that glutamate causes apoptosis of retinal neurons via the excessive formation of peroxynitrite, and that the neuroprotective effect of the psychotropic 9-tetrahydroxycannabinol (THC) or nonpsychotropic cannabidiol (CBD) is via the attenuation of this formation. Excitotoxicity of the retina was induced by intravitreal injection of N-methyl-D-aspartate (NMDA) in rats, which also received 4-hydroxy-2,2,6,6-tetramethylpiperidine-n-oxyl (TEMPOL,a superoxide dismutase-mimetic), N—nitro-L-arginine methyl ester (L-NAME, a nitric oxide synthase inhibitor), THC, or CBD. Retinal neuron loss was determined by TDT-mediated dUTP nick-end labeling assay, inner retinal thickness, and quantification of the mRNAs of ganglion cell markers. NMDA induced a dose- and time-dependent accumulation of nitrite/nitrate, lipid peroxidation, and nitrotyrosine (foot print of peroxynitrite), and a dose-dependent apoptosis and loss of inner retinal neurons. Treatment with L-NAME or TEMPOL protected retinal neurons and confirmed the involvement of peroxynitrite in retinal neurotoxicity. The neuroprotection by THC and CBD was because of attenuation of peroxynitrite. The effect of THC was in part mediated by the cannabinoid receptor CB1. These results suggest the potential use of CBD as a novel topical therapy for the treatment of glaucoma.

b) Crandall J, Matragoon S, Khalifa YM, Borlongan C, Tsai NT, Caldwell RB, Liou GI
Neuroprotective and Intraocular Pressure-Lowering Effects of (-)Delta-Tetrahydrocannabinol in a Rat Model of Glaucoma. Ophthalmic Res 2007 Feb 2; 39(2):69-75.
In glaucoma, retinal ganglion cell (RGC) death is induced by many risk factors, including ocular hypertension. It has been proposed that glutamate-mediated oxidative stress may also contribute to this RGC death. Cannabinoids are known to possess therapeutic properties including ocular hypotension and antioxidation. In this study, we test the hypothesis that (-)Delta(9)-tetrahydrocannabinol (THC) lowers intraocular pressure (IOP) and prevents RGC death in a rat model of glaucoma.
Results demonstrate that THC is a neuroprotectant that preserves RGCs in an experimental model of glaucoma, possibly through a reduction in IOP.

3) Cannabis Increases Blood circulation to eye.

a) Dronabinol and retinal hemodynamics in humans. Plange N, Arend KO, Kaup M, Doehmen B, Adams H, Hendricks S, Cordes A, Huth J, Sponsel WE, Remky A. (2007) American Journal of Ophthalmology. Jan;143(1):173-4.
Results: The retinal arteriovenous passage time decreased from 1.77 0.35 seconds to 1.57 0.31 seconds (P = .028). Systemic blood pressure and heart rate were not statistically significantly altered.
Conclusions: Cannabinoids, already known for their ability to reduce IOP, may result in increased retinal hemodynamics. This may be beneficial in ocular circulatory disorders, including glaucoma.

b) Cannabinoid agonists induce relaxation in the bovine ophthalmic artery: evidences for CB1 receptors, nitric oxide and potassium channels. British Journal of Pharmacology (Maria Rosaria Romano, Marcello D Lograno) Volume 147 Issue 8 (2006).
Glaucoma pathophysiology appears to involve vascular deficits, which may contribute to initiation and progression of the disease..... These data suggest that anandamide and WIN55212-2 relax the bovine ophthalmic artery by involving CB1 the cannabinoid receptor-sensitive pathway. In endothelium-intact arteries, relaxation occurs through activation of nitric oxide synthase cyclic GMP and Ca2+-activated K+ channels. They also cause endothelium-independent relaxation by involving potassium channel opening. British Journal of Pharmacology (2006) 147, 917–925.

4) Cannabis Lowers IOP - numerous studies. Most importantly works synergysticaly in an additive way with some other glaucoma medications.

5) Glaucoma as endocannabinoid deficiency.

a) Finding of endocannabinoids in human eye tissues: Implications for glaucoma.
June Chena, Isabel Matiasb, Tim Dinha, Ta Lua, Sonia Veneziab, Amelia Nievesa, David F. Woodwarda and Vincenzo Di Marzob, Department of Biological Sciences, Allergan Inc., Irvine, CA, USA. Endocannabinoid Research Group, Institute of Biomolecular Chemistry, Consiglio Nazionale delle Ricerche, Pozzuoli (Napoli), Italy. Received 9 March 2005. Available online 23 March 2005.
Abstract
Cannabinoid CB1 receptors are involved in ocular physiology and may regulate intraocular pressure (IOP). However, endocannabinoid levels in human ocular tissues of cornea, iris, ciliary body, retina, and choroid from normal and glaucomatous donors have not been investigated. Anandamide (N-arachidonoylethanolamine; AEA), 2-arachidonoylglycerol (2-AG), and the anandamide congener, palmitoylethanolamide (PEA), were detected in all the human tissues examined. In eyes from patients with glaucoma, significantly decreased 2-AG and PEA levels were detected in the ciliary body, an important tissue in the regulation of IOP. The findings suggest that these endogenous compounds may have a role in this disease, particularly with respect to regulation of IOP.

6) Other benefits include the following and likely others

a) Cannabis improves night vision: a case study of dark adaptometry and scotopic sensitivity in kif smokers of the Rif mountains of northern Morocco.
Journal of Ethnopharmacology, Volume 93, Issue 1, July 2004, Pages 99-104
E. B. Russo, A. Merzouki, J. Molero Mesa, K. A. Frey and P. J. Bach E. B. Russo, , a, A. Merzoukib, c, J. Molero Mesab, K. A. Freyd and P. J. Bache. 2235 Wylie Avenue, Missoula, MT 59802, USA; Department of Botany, Faculty of Pharmacy, University of Granada, Granada 18071, Spain; Laboratory of Ethnobotany, Faculty of Sciences, University Abdelmalek Essaadi, Tétouan, Morocco; Montana State University School of Nursing, 236 Corbin Hall, University of Montana, Missoula, MT 59812, USA; Montana Neurobehavioral Specialists, 900 North Orange St., Missoula, MT 59802, USA.
Received 1 January 2003; Revised 1 March 2004; accepted 18 March 2004.
Abstract
Previous reports have documented an improvement in night vision among Jamaican fishermen after ingestion of a crude tincture of herbal cannabis, while two members of this group noted that Moroccan fishermen and mountain dwellers observe an analogous improvement after smoking kif, sifted Cannabis sativa mixed with tobacco (Nicotiana rustica). Field-testing of night vision has become possible with a portable device, the LKC Technologies Scotopic Sensitivity Tester-1 (SST-1). This study examines the results of double-blinded graduated THC administration 0–20 mg (as Marinol®) versus placebo in one subject on measures of dark adaptometry and scotopic sensitivity. Analogous field studies were performed in Morocco with the SST-1 in three subjects before and after smoking kif. In both test situations, improvements in night vision measures were noted after THC or cannabis. It is believed that this effect is dose-dependent and cannabinoid-mediated at the retinal level. Further testing may assess possible clinical application of these results in retinitis pigmentosa or other conditions.