Scientific Evidence

The effect of cannabis on intraocular pressure (IOP) in normal subjects has been well studied, however, the effect on glaucoma patients is less well known, with only a handful of patients studied. Only one study used herbal cannabis, the rest have used cannabinoids.

The Hepler & Frank study (1971) found that oral or smoked cannabis reduced intraocular pressures in normal subjects for about 4 to 5 hours with "no indications of any deleterious effects ... on visual function or ocular structure". They concluded that cannabis may be more useful than conventional medications and probably works by a different mechanism.

Almost all of the studies using cannabinoids have been double-blind and placebo controlled. Two studies were of the effects of oral or smoked THC on IOP in normal subjects. Hepler et al. (1976) reported that the drop in IOP was dose-related. Jones et al. (1981) found that tolerance to the effects quickly built up, and there was a rebound in IOP to above baseline levels when treatment was stopped. Another two studies used intravenous infusions of various cannabinoids. Perez-Reyes et al. (1976) found that only the cannabinoids that had psychoactive effects produced a drop in IOP. Cooler & Gregg (1977) reported a drop in IOP but increased anxiety. The effects of cannabinoids on IOP were confirmed in numerous animal experiments, reviewed by Adler & Geller (1986).

Three orally-taken synthetic cannabinoids have been investigated by Newell et al (1979) and Tiedeman et al (1981). These were given to patients who already had a high IOP. The cannabinoid BW146Y and Nabilone had the same efficiacy as smoked cannabis (but still had a short duration). BW29Y however did not have any significantly beneficial effect.

The few studies on glaucoma patients all involve small numbers of patients. Hepler et al. (1976) found that when THC was smoked for months at a time by glaucoma patients, the effect on intraocular pressure stayed constant and there was no deterioration of vision. However only 7 of the 11 patients showed the effect. Merrit et al. (1980) carried out a double-blind and placebo controlled study on 18 patients and found a significant reduction in IOP but unwanted cardio-vascular and pyschoactive side-effects.

Applying cannabinoids directly to the eyes should remove the side-effects but is proving difficult since they are not water-soluble. Merrit et al (1981) applied THC to only one eye in 8 patients, but found an effect on IOP in both eyes suggesting that the THC had been adsorbed into the bloodstream, rather than acting topically. However his patients reported no pyschoactive side-effects. Two other studies applying THC directly to the eye (as an eye drop) by Green et al (1982) and Jay et al (1983) showed no reduction in IOP.

In one report (Green et al, 1978) the solubility issues were to some extent overcome by dissolving THC in mineral oil, and using the resultant mixture as an eyedrop. THC, cannabinol, 8-alpha- and 8-beta-11-dihydroxy-delta-9-THC all produce a lowering of IOP when topically adminstered to rabbits. They result in no psychoactive effects and appear to be as efficacious as the traditional eye-drops used to reduce IOP (e.g. Pilocarpine) and often work for longer periods of time.

A non-psychoactive extract of cannabis was tested in combination with Timolol eye-drops in patients with high IOP by West et al (1980). They found that the effects of the two medications were complementary and were even effective in some cases where other medications had failed.

As mentioned above, there are other approaches to aiding glaucoma sufferers, including attempting to provude some neural protection. More research on this approach (with or without cannabis) needs to be done, but Yoles et al (1996) used a synthetic cannabinoid HU-211 which is thought to have potential neuroprotective effects. More recent (animal-based) studies by Beilin et al and Naveh et al have shown that this particular cannabinoid also lowers IOP.

Despite the research already done, much more seems to be needed in order to determine the optimum way to help sufferers of glaucoma with cannabis-based medications, if indeed they prove to be beneficial to sufferers compared to existing medications. Amongst others, both the Australian National Task Force on Cannabis (Hall et al, 1994) and a National Institute of Health workshop have called for more research to be done on this topic.

References
Adler, M.W., & Geller, E.B., (1986) Ocular effects of cannabinoids. In Cannabinoids as Therapeutic Agents ed. R Mechoulam CRC Press pp51-70.

Beilin et al. (2000) Pharmacology of the intraocular pressure (IOP) lowering effect of systemic Dexanabinol (HU-211), a non-psychotropic cannabinoid.J Ocul Pharmacol Ther 16: 217-230.


Cooler, P. & Gregg, J.M. (1977) Effect of delta-9-tetrahydrocannabinol on intraocular pressure. Southern Medical Journal 70: 951-954.

Green K, Roth M. (1982) Ocular effects of topical administration of delta-9- Tetrahydrocannabinol in man. Archives of Ophthalmology 100:265-267.

Green, K., Wynn, H., and Bowman, K.A (1978): A comparison of topical cannabinoids on intraocular pressure. Exp. Eye Res. 27: 239­246.


Hall et al. (1994) The Health and Psychological Consequences of Cannabis Use, Canberra, Australian Government Publishing Service 199.


Hepler, R.S. & Frank, I.M. (1971) Marihuana smoking and intraocular pressure. J.Am.Med.Ass. 217, 1392.

Hepler, R.S., Frank, I.M. & Petrus, R. (1976) Ocular effects of marihuana smoking. In The Pharmacology of Marihuana ed. M.C. Braude & S. Szara. Raven Press, New York, pp815-824.

Institute of Medicine (1999) Marijuana and medicine: Assessing the science base. National Academy Press

Jay WM, Green K. (1983) Multiple-drop study of topically applied I % D9 Tetrahydrocannabinol in human eyes. Archives of Ophthalmology 101 :591-593

Hollister L (1986) Health aspects of cannabis, Pharmacological Reviews, The American Society for Pharmacology
and Experimental Therapeutics


Merritt, J.C., Crawford, W.J., Alexander, P.C., Anduze, A.L. & Gelbart, S.S. (1980) Effect of marijuana on intraocular and blood pressure in glaucoma. Ophthalmology 87: 222-228.

Merritt, J.C., Olsen, J.L., Armstrong, J.R. & McKinnon, S.M. (1981) Topical delta-9-tetrahydrocannabinol in hypertensive glaucomas. J. Pharm. Pharmacol. 33: 40-41.

National Institutes of Health (1997) Workshop on the Medical Utility of Marijuana, Report to the Director. Washington D.C.


Naveh et al. (2000) A submicron emulsion of HU-211, a synthetic cannabinoid, reduces intraocular pressure in rabbits. Graefes Arch Clin Exp Opthalmol 238: 334-338.


Newell FW, Stark P. Jay WM, Schanzlin DJ. (1979) Nabilone: a pressure-reducing synthetic benzopyran in open-angle glaucoma. Ophthalmology 86:156-160.


Perez-Reyez, M., Wagner, D., Wall, M.E. & Davis, K.H. (1976) Intravenous administration of cannabinoids and intraocular pressure. In The Pharmacology of Marihuana ed. M.C. Braude & S. Szara. Raven Press, New York, pp829-832.

Tiedeman JS, Shields MB, Weber PA, Crow JW, Cocchetto DM, Harris WA, Howes JF. (1981) Effect of synthetic cannabinoids on elevated intraocular pressure. Ophthalmology 88:270-277.

West, M.E., and Lockhart, A.B. (1980) The treatment of glaucoma using a non­psychoactive preparation of Cannabis sativa. West Indian Med. J. 29: 390.


Yoles E, Belkin M, Schwartz M. (1996) HU-211, a nonpsychotropic cannabinoid, produces short- and long-term neuroprotection after optic nerve axotomy. Journal of Neurotrauma 13:49-57.


Other References

Colasanti, B.K. 1986. Review: Ocular hypotensive affect of marihuana cannabinoids: correlate of central action or separate phenomenon. J. Ocular Pharmacology 2(3): 295-304.

Colasanti, B.K. et al., 1984. Ocular hypotension, ocular toxicity, and neurotoxicity in response to marijuana extract and cannabidiol. Gen. Pharmacol. 15: 479.

Colasanti, B.K. et al., 1984. Intraocular pressure, ocular toxicity and neurotoxicity after administration of delta-9-tetrahydrocannabinol or cannabichromene. Exp. Eye Res. 38: 63.

Colasanti, B.K. et al., 1984. Intraocular pressure, ocular toxicity and neurotoxicity after administration of cannabinol or cannabigerol. Exp. Eye Res. 39: 231-259.

Crawford, W. & Merritt, J.C., 1979. Effects of tetrahydrocannabinol on arterial and intraocular hypertension. Int. J. Clin. Pharmacol. Biopharmacol. 17: 191-196.

Green, K. and McDonald, T.F., 1987. Ocular toxicology of marijuana: an update. J. Toxicol.-Cut. and Ocular Toxicol. 6: 309-334.

Levitt, M. et at., 1981. Physiologic observations in a controlled clinical trial of the antiemetic effectiveness of 5, 10, and 15 mg of delta-9-tetrahydrocannabinol in cancer chemotherapy: ophthalmologic implications. J. Clin. Pharmacol. 21: 103S.

Merritt, J.C. et at., 1980. Oral delta-9-tetrahydrocannabinol in heterogenous glaucomas. Ann. Opthalmol. 12: 8.

Merritt, J.C. et at., 1981. Topical delta-9-tetrahydrocannabinol and aqueous dynamics in glaucoma. J. Clin. Pharmacol. 21: 467S-471S.

Merritt, J.C. et at., 1982. Topical delta-9-tetrahydrocannabinol as a potential glaucoma agent. Glaucoma 4: 253-255.

Shapiro, D., 1974. The ocular manifestation of the cannabinoids. Ophthalmologia 168: 366-369.

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Glaucoma and Cannabis

Fourteen percent of all blindness in America is from glaucoma, a progressive loss of vision. Cannabis smoking would benefit 90% of our 2,500,000 glaucoma victims, and is two to three times as effective as any current medicines for reducing ocolar pressure. And, cannabis use has no toxic side effects to the liver and kidneys, nor is there any danger of the legal pharmaceutical glaucoma drugs/drops. Most California eye doctors will discreetly advise their patients to use "street" marijuana in addition to their toxic legal glaucoma medicines.

Discovery of the ability of cannabis to lower intraocular pressure was more or less fortuitous. Intraocular pressure was measured as part of a multifaceted study of the effects of chronic smoking of large amounts of cannabis. Intraocular pressure was found to decrease as much as 45% in 9 of 11 subjects, 30 min after smoking. Lowered intraocular pressure lasted 4 to 5 h after smoking a single cigarette. Its magnitude was unrelated to the total number of cigarettes smoked. The maximal effect on intraocular pressure was produced by the amount of THC absorbed in a single cigarette containing 19 mg of THC. When patients with ocular hypertension or glaucoma were tested 7 of 11 showed a fall of intraocular pressure of 30%. Confirmatory evidence was obtained from a trial in which i.v. injection of THC in doses of 22 ug/kg and 44 ug/kg produced an average fall in intraocular pressure of 37%, with come decreases as much as 51% . Many experiments done in rabbits using various routes of administration, including instillation of cannabinoids into the eye, have confirmed the ability of cannabis to reduce intraocular pressure.




Elvy Musikka on Cannabis and Glaucoma; Elvy Musikka is a woman in her mid-forties who lives in Hollywood, Florida. This is her story:

In late February 1975 I went to see Dr. Rosenfeld, a general practitioner in the Ft. Lauderdale area. He concluded a very thorough examination and said my eyes had been stricken with glaucoma. My [intraocular fluid] pressures were in the high 40s [pressure in the low teens is normal], and Dr. Rosenfeld insisted I see an ophthalmologist immediately. His suspicions were confirmed and I was started on pilocarpine eyedrops.

Elvy Musikka on Cannabis and Glaucoma. from the chapter, "Glaucoma, " in Marijuana, The Forbidden Medicine, pp. 52-57, by Dr. Lester Grinspoon, M.D., Associate Professor of Psychiatry, Harvard Medical School. and James B. Bakalar, associate editor of the Harvard Mental Health Letter and a Lecturer in Law in the Department of Psychiatry at Harvard Medical School Yale University Press, New Haven, 1993, ISBN 0-300-05994-9.
And …

“Blinded by Ignorance” Elvy Musikka (article) by Dana Larsen. “Elvy is one of only eight people in the United States who receives legal medical marijuana from the government. Every three months she receives about 600 grams of admittedly poor quality marijuana in the form of hundreds of pre-rolled joints.

Since receiving her first legal prescription in 1988, the fifty-something Elvy has tirelessly devoted herself to travelling across the US, spreading the good news about the beneficial healing effects of marijuana.

"I realize now that I was never blinded by glaucoma, I was blinded by ignorance" Elvy Musikka. Blinded by Ignorance. Interviewed by Dana Larsen ... glaucoma, I was blinded by ignorance. No one in their right mind would have made the decision I made if they had known that cannabis ...


"Joe Smith" - Glaucoma; Patient Story (article) ["Joe Smith" is not this patient's real name, but is being used to protect his privacy. He has consented to be named and to meet with any medical or media professional who wishes to confirm the facts of his story.]

I was born and raised in Johnson County, Missouri, on the northwest Ozark prairie edge. From the start, I was a hunter and naturalist. By junior high, I had hunted all upland game ... here the old-timers I hunted with were in the ir 70s and 80s. I went to the University of Missouri - Columbia in wildlife management for three years, taught field ornithology the last two years, and managed to take several graduate courses in biological sciences and art ...

Rx Cannabis Now! is a website dedicated to the re-legalization of cannabis as medicine. As a glaucoma patient and arthritis sufferer, I know cannabis is good, natural medicine. Rx Cannabis Now! features photos, information and links about cannabis events I have participated in, from the Action Class in Philadelphia Hearing in March 1999, to San Francisco's version of the Million Marijuana March on May 1, 1999, to activism and protest in Washington D.C. in October 1999, to the first National Conference for Cannabis Therapeutics in April 2000 in Iowa City, and, activism and protest in New Jersey in October 2000. Please visit my other sites below. Thanks for stopping by! - Gary Storck.

MED CAN related ORGS & BIZ

Robert A. Nelson: Hemp & Health on - Glaucoma: --- “Several million people worldwide are afflicted with glaucoma, in which the unchecked rise of intraocular pressure (IOP) causes irreparable damage of the retina and optic nerve, resulting in blindness. About 250,000 Americans suffer from glaucoma, and several thousand people go blind from the affliction each year in the USA. Glaucoma is somewhat controllable with medications, all of which are attended by dangerous side-effects -- with the exemption of cannabis.”

Hemp & Health Internet Edition by Robert A. Nelson (online) ... Cannabis sativa, the "True Hemp", is tightly woven into the tapestry of human life ... prescription that is prescient of the modern use of cannabis in the treatment of glaucoma: ... REX RESEARCH was established in 1982 by Robert A. Nelson to archive and distribute information about "unconventional", suppressed, dormant, or emerging sciences, technologies, inventions, theories, therapies, and miscellaneous alternatives that offer real hope of liberating humanity. Contact Rex Research - rexresearch.com * PO Box 19250, Jean NV 89019 USA *

Cannabis as Medicine (ORG, CLAW) The Massachusetts Cannabis Reform Coalition, Inc. (MASS CANN) is working to build a consensus for a more moral and rational public policy regarding all uses of the cannabis plant. ... Cannabis as Medicine. Home. Freedom Rally ... (Journal of Neurology, 236: 120, 1989). Glaucoma reduces intraocular pressure to prevent degenerative blindness ...
]

Medical Marijuana Users Guide - Concept420 - Marijuana Entertainment and Information ... Cannabis can be used as an antiemetic, a drug which relieves nausea and ... intraocular pressures in end-stage glaucoma. Cannabis however lowers intraocular pressures dramatically ...

SIMM (Stichting Institute of Medical Marijuana) was launched in The Netherlands in 1993. Our purpose ... To produce and supply patients with high quality medical cannabis, at the lowest possible price; organically grown in soil in a clean environment, and properly handled throughout the growing/curing process.

Glaucoma is a progressive and incurable disease of the eye that is caused by pathological increases in intra-ocular pressure. Left untreated, glaucoma leads to blindness. ... general discussion of the use of medical cannabis for glaucoma. There will soon be available a ... published scientific studies regarding the use of medicinal cannabis for glaucoma. ...
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Cannabis Helps - Glaucoma

The human eyeball is filled with fluid which exerts pressure to keep the eyeball spherical. Glaucoma is a condition where the channels through which the fluid flows gradually become blocked, and the intraocular pressure (IOP) gradually increases causing increasing damage to the optic nerve and gradual deterioration of vision.

Glaucoma is the second-largest cause of blindness, and affects 1.5% of 50-year olds and 5% of seventy-year olds.

Standard treatments have unpleasant or dangerous side effects, and have little effect on intraocular pressures in end-stage glaucoma. Cannabis however lowers intraocular pressures dramatically, with none of the serious side effects.

Patients who find that standard medicines do not help their conditions report that smoking cannabis quickly restores their vision. Many long-term glaucoma patients have successfully maintained their sight using cannabis for 20 or 25 years, and avoided the gradual painful deterioration to blindness that is otherwise inevitable.

There are concerns about the effects on the cardio-vascular system. These disadvantages are especially significant when one takes into account that a dose of cannabis needs to be taken about every 4 hours for the full benefits to occur.

Despite the possible drawbacks, one should be reminded that using cannabis evidently does some glaucoma sufferers a lot of good. 2 out of the 8 patients who are legally permitted to use cannabis medicinally in the US have used government-supplied cannabis for over 10 years to maintain their sight. It seems cruel to prohibit and, indeed, punish the huge numbers of glaucoma sufferers that could be helped by cannabis. Following a review of existing research, the Australian National Task Force on Cannabis concluded that it would not be desirable to criminalise such users.

Ironically, the discovery that cannabis lowers intraocular pressure was made accidentally during a police experiment. They were trying to discover if cannabis caused pupil dilation in users so that they could detect and arrest them more easily!

With the 1999 release of the Institutes of Medicine Report on Medicinal Marijuana, the issue of therapeutic cannabis has come to the mainstream. The report did indicate that marijuana does indeed lower intraocular pressure. Unfortunately this highly politicised report took the position that "conventional" glaucoma treatments are not only superior to cannabis, but also less likely to have side effects.

Indeed, the opposite is true. The fact that of the eight surviving patients grandfathered into the discontinued compassionate IND program who the federal government provides 300 joints per month to, three are glaucoma patients, demonstrates marijuana's efficacy in glaucoma treatment.

source: http://www.budbuddies.com/cannabishelps/glaucoma.htm

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MI: Saginaw News: 'Trying to ease my suffering'

Posted by Gary Storck
Sunday, November 30, 2008

The Saginaw News published this article, which begins with a compassionate look at a patient dealing with serious illness who clearly benefits from legal access to medical cannabis. The second half reports on the naysayers and quacks who dismiss medical cannabis as not needed. It's shameful for a physician to close their minds to any potential treatment. To do so with cannabis with its incredible safety and lack of toxicity, when they have patients who could benefit, is nothing short of malpractice.

'Trying to ease my suffering'
THE SAGINAW NEWS click here.
Sunday, November 30, 2008

Unlike former president Bill Clinton, Charles H. Snyder III inhales.

On bad days, he heats up marijuana three times a day. On good days, it's less.

However, on bad days -- when the chronic pain from glaucoma and the rare genetic disorder Nail-patella syndrome becomes unbearable -- the 31-year-old Genesee County resident sniffs more marijuana through an electric vaporizer.

''For seven years, doctors tried to find the right formula of pain pills to help me lead a more normal life,'' said the married father of a toddler daughter. ''They never found the right combination or dosage amount that didn't make things worse. It's not about getting high. I'm not a thug. I'm trying to ease my suffering.''

Snyder estimates he's one of approximately 50,000 Michigan patients struggling with chronic pain who rejoiced when citizens passed the controversial Proposal 1 in the Nov. 4 general election.

When the proposal takes effect Thursday, Michigan will join Arkansas, California, Colorado, Hawaii, Maine, Montana, Nevada, New Mexico, Oregon, Rhode Island, Vermont and Washington in permitting medical marijuana to treat cancer, glaucoma, multiple sclerosis, epilepsy, chronic pain and HIV/AIDS -- without fear of state prosecution.

Compassionate?

Snyder is a member of the Ferndale-based medical marijuana reform advocacy group Michigan Coalition for Compassionate Care.

An unemployed construction worker, he began using marijuana after reading about the relief it provides. Absent or underdeveloped kneecaps and thumbnails characterize Nail-Patella, which causes bone, joint, fingernails and kidney abnormalities.

He began buying it seven years ago from ''underground people I trust.''

He uses a vaporizer to heat the drug to 356 to 392 degrees -- nearly the same temperature as baking a cake -- to release active cannabinoids, but below the point where the heat produces carcinogenic tars and noxious gases.

''There are less than 100 people in mid-Michigan that I'm aware of using marijuana for medical reasons, but who knows for sure, since people are afraid of being put through the ringer or arrested,'' Snyder said. ''For me it's more important to have some type of quality of life, so the fear and danger involved with buying illegal drugs are worth it because I'm taking a more proactive role in my overall well being.''

The proposal allows people to use and grow marijuana to treat certain medical conditions with a physician's authorization. However, users of the mind-altering drug -- also known as cannabis, weed, herb, maryjane, reefer, 'the chronic', pot and blunts -- must register with the state.

Once licensed, patients may possess 2.5 ounces or less of marijuana and cultivate no more than 12 plants in an enclosed, locked facility, according to the Michigan Medical Marijuana Act.

A federal no-no

That's not the case federally, warns Saginaw County Prosecutor Michael D. Thomas.

''Proposal 1 is a state issue, there's nothing that will exempt medical marijuana users from federal prosecution,'' Thomas said. ''The last I heard, our federal drug czar (John P. Walters) has not given up the ability to prosecute people and is very much against its use.''

The Food and Drug Administration continues to classify marijuana as a Schedule I controlled substance having a high potential for abuse and no medicinal value -- making it illegal to possess or sell.

State police and Department of Health officials have an additional 120 days to create and implement rules regulating how doctors prescribe it, the distribution, patient use and issuing permits, Thomas said.

''The real irony is America has spent decades and countless amounts of money advertising how toxic cigarettes are and the dangers of second-hand smoke. From all of the information I've read smoking marijuana is 10 times more carcinogenic than tobacco,'' Thomas said.

Dr. Michael C. Cappelli, 45, agrees. The radiation oncologist at St. Mary's of Michigan Seton Cancer Institute, 800 S. Washington in Saginaw and Michigan State Medical Society board member has ''mixed feelings'' about the initiative's passage.
''I can't believe it passed,'' he said. ''It's terrible public policy that can become a bridge to federal legalization. I'm in favor of relieving pain and suffering, but the problems, such as lung damage, associated with smoking pot will cause greater harm to public safety than any benefits. It also opens a Pandora's box for law enforcement.''

However, Cappelli is staying open-minded.

''There are so many new legal drugs out there to work with there's no reason we shouldn't be able to find a legal medication that works. ... (My feelings) may change, especially if it's the only thing that will relieve a patient's chronic pain.''

Glaucoma specialist and ophthalmologist Dr. Usha Bulusu, who has a private practice at 4705 Towne Centre in Saginaw Township has ''mixed emotions'' as well.

''I don't see a need for it,'' she said. ''While it does reduce the painful pressure in the eyes of patients with glaucoma, it's not a suitable treatment because the effects only stay in the body for a limited amount of time and the best treatment should provide long-term, consistent management.''

''There are no clear answers. Depending on the circumstances, it could be a good thing for those who really need it. Or it could create a channel for abuse ... and that's the problem.''

source: http://www.mlive.com/news/saginawnews/inde....xml&coll=9

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