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Marijuana And Glaucoma…


Written by Larry J Alexander OD FAAO Wednesday, 17 April 2013

From Brewer and Shipley.  This song is about drugs, especially marijuana. A "Toke" is a puff from a marijuana cigarette or pipe. Tom Shipley explained: "When we wrote 'One Toke Over the Line,' I think we were one toke over the line. I considered marijuana a sort of a sacrament... If you listen to the lyrics of that song, 'one toke' was just a metaphor. It's a song about excess. Too much of anything will probably kill you."


As children we all sang the following rhyme going around in a circle smiling the entire way.  Did you ever think you were singing about the BUBONIC PLAGUE?





The interpretation of this nursery rhyme from the following website is very dark but is it fact?

Ring Around the Rosie. When a person contracted the Bubonic Plague, they would gain rose-colored, puss-filled sores on their body called rosies. As the infection spread, rings would wind around the rosies. "Ring around the rosie," refers to these rings.

Pocket Full of Posies. During the time of the Bubonic Plague, people realized that it was harmful to go around the body of someone who had died from the plague. The common practice in some areas of Europe was to fill the shirt or jacket pocket of the deceased with posies so that others would know to leave the body alone. "Pocket full of posies," was what would soon happen after the person started getting the rings around the rosie. Once the rings started to form, the undertaker would be called to prepare the posies.

Ashes Ashes. Once the body of the person who had died from the plague had been taken away, it would be burned. This is essentially when cremation started as a form of burial. There was a lot of worry that extra handling of the body could cause people to get sick. There was also worry by some that the body would come back in the form of a vampire or some other type of the walking dead. Burning the body was the only true option they had.

We All Fall Down. It was believed by many that eventually that Bubonic Plague would wipe out all of civilization. It is understandable why they had this belief because of the number of people that were dying everyday from the Plague. The Black Death killed off an estimated 20-35% of the population of Eurasia during its historic run. It was nearly impossible for anyone to not know at least one person who died from the Plague at the time.

This nursery rhyme has been with us for centuries, and will probably be sung for centuries more. It is interesting about how many people have sung this song without knowing what it meant. 

But is this interpretation really the truth or just a fabrication?

Refuted by the following website.



Marijuana is a very effective method of controlling glaucoma with minimal side effects.  But is this really the truth or just a fabrication?  This little “fact” is investigated herein.


 The political system is hot with the issue of the legalization of marijuana.  As of April 12, 2013 there were 18 states and DC that had legalized the medical use of marijuana and 10 states with pending legislation.  Colorado and Washington are states where recreational marijuana is legal.  This discussion is neither in support nor in opposition to the concept of the use of marijuana for medical reasons.  It is rather a look at the scientific basis for the potential use of this substance in the management of glaucoma.  This discussion is also an attempt to increase the transparency of the issue of the use and abuse of marijuana. 

Not to necessarily cast a negative shadow on marijuana abuse in the US, one must consider other potential abuse issues as well.  Abuse of prescription drugs has become an epidemic.  “In 2010, approximately 16 million Americans reported using a prescription drug for nonmedical reasons in the past year…”

Facts About Prescription Drug Abuse


About 7 Million Americans Reported Past-Month Use of Prescription Drugs for Nonmedical Purposes in 2010

Coincidently, the most prescribed drug in the US in 2010 was hydrocodone at 131.2 million written. .  Likewise one must consider the fact that alcohol is considered the most abused drug in the US. is an excellent source to review much of the current thought process surrounding drug abuse. 

 Setting the stage with the potential of all substance abuse, the topic of medical use of marijuana may now be addressed.


The use of marijuana is popular because of reported feelings of euphoria, relaxation and relaxation.  There is also the perception that this “soft” substance is not addictive.

Marijuana is prepared from the plant Cannabis sativa and is reported to be the most widely used “illicit” drug in the United States.  Marijuana has been reported to have adverse psychosocial and health effects. 1 Marijuana is prepared from the leaves, stems and dried flower buds of the plant while hashish is the resin obtained from the flowering buds.  These preparations are then either smoked (marijuana/ganja), mixed with food and consumed orally (bhang) or smoked or consumed orally (hashish oil).  All variations are psychoactive products.  The cannabis plant contains 61 cannabinoids. Smoking and inhaling cannabis results in very rapid concentrations in the blood.  The drug is detected in plasma within seconds of the first puff and attains peak concentration within 3-10 minutes. 2-6

In contrast oral ingestion results in slower absorption but higher concentration. 7-8

The primary psycho-active constituent of cannabis, delta 9-tetrahydrocannabinol (9_THC), may create a number of pharmacological effects in animals and humans. Although it is used as a recreational drug, it can potentially lead to dependence and behavioral disturbances and its heavy use may increase the risk for psychotic disorders. 9 Cannabinoids exert physiological reactions by interacting with specific cannabinoid receptions in the brain (cognition, memory, reward, anxiety, pain, sensory perception, motor coordination and endocrine function). 10-12 In the periphery the receptors are primarily in the spleen and other tissue that interface in the immune system reactions. 13-14 There is also the suggestion that cannabinoids may influence IOP through a prostaglandin mediated mechanism. 15-18

The action of cannabinoids in ocular tissue is somewhat elusive.  The main site of action regarding IOP does not appear to be in the central nervous system.  There do appear to be ocular cannabinoid receptors in the ciliary epithelium, the trabecular meshwork, Schlemm’s canal, the ciliary muscle, the ciliary body vessels and the retina.  The proposal for action of the cannabinoids in the ocular tissue is that the effect occurs in both production and outflow of aqueous. 19-25

It has been postulated that synthetic cannabinoid receptor agonists acting as activators of the endocannabinoid system may offer more effective and safer applications. 26

Control of quality of the marijuana is certainly a question.  Regulations have not yet been refined to assure the efficacy or composition of the product.  This recent excerpt from summarizes some of the thoughts regarding quality assurance.

“A proposed law in Oregon, hb3460, would require the testing of pot for mold, mildew and pesticides as part of a regulated dispensary system.As it currently stands, medical marijuana users are largely on their own. They either have to find growers they trust or rely on collectives that vouch for the quality of the pot. Pat Marshall is in the business of eliminating ambiguity for medical marijuana users. He’s a chemist who tests marijuana for local collectives. He said patients have a lot of uncertainty about the product they’re buying.
“They’re like, ‘I don’t want another one of those brownies because the last time I at one of those it put me on the couch for six hours,’” Marshall explained.  Marshall said he’ll find pesticides in one of out every 20 samples he tests. That’s concerning when you consider the thousands of patients who smoke marijuana and inhale those chemicals into their lungs.

Is There Really a Downside to Marijuana Use?

 This discussion cannot be a social statement regarding the use of marijuana but a couple of issues regarding the downside must be highlighted.  As with all pharmaceutical agents and substance abuse issues such as alcohol and tobacco use, side effects are commonplace.

One of the primary questions regarding the use of marijuana surrounds the question of addiction. It is estimated that there are 119 to 224 million users of Cannabis worldwide.  It has been reported that with repeated exposure the brain neuro-adaptations persist long after the initial drug effects, contributing to negative affective states during withdrawal and potentiating relapse. 27

Overall the evidence for dependence on cannabis is growing. 8,28-34 It has been reported that over 50% of cannabis users appear to have impaired control over their use of the drug. 35 Additionally, it is reported that during abstinence between 61-96% of users become irritable, anxiety ridden with cravings and disrupted sleep. 36-38 Analysis of the use of marijuana in school children in the United Kingdom showed more than 40% of 15-16 year olds and 59% of 18 year olds admitted to have used cannabis at least once. 39

Unfortunately, it is also reported that cannabis has been associated with crime, violence, psychosis, aggression, ADHD, conduct issues, learning disorders, use of other illicit drugs, and under-performance in school as well. 40-44

Mood and memory changes such as panic and paranoia, rapid changes in heart rate and diastolic pressure, dry mouth, increased appetite, vasodilation, decreased respiratory rate, lung damage and altered EEG are also reported. 45-50

Reduction of systemic blood pressure and tachycardia occur as well.  51

Another question that looms is the premise that there is a potential transition from substance abuse to mental illness.  One recent study reported “Lifetime diagnoses of any Mental Illness, and particularly personality disorders and psychotic disorders, were found to be associated with higher prevalence of transition from substance use to Substance Use Disorders across most categories of substances. 52 Other research relates the link to psychiatric disorders but also point to the fact that it is difficult to develop a direct cause-effect relationship. 53-57 A 2013 article summarizes that “For cannabis, tobacco, and alcohol the estimated societal disease burden was higher than at individual level. The present ranking solely based on their physical harm was very similar to a previous ranking based on a combination of dependence liability, physical harm and social impairments.” 58

While marijuana has the potential for multiple methods of consumption the most recognized is the inhalation via some form of smoking.  Intuition alone would dictate that the inhalation via smoking can have negative effects on thesystem including the increased risk of lung disease. 59 The impact of marijuana as well may extent to the indirect effect on others (motor vehicle accidents among those at risk) and on the fetus.  60-61

 Is There Really an Upside to Marijuana Use in Glaucoma?

The medical benefits of cannabis have long been recognized.  The drug has been shown to have therapeutic potential as an appetite stimulant, an anti-emetic, and an anti-spasmodic.  It has also been suggested for managing epilepsy, glaucoma and asthma. 62-64 In 1971 it was reported that a 25 to 30% IOP lowering effect of smoking marijuana occurred in a small group.  This was a dose-response relationship lasting only 3-4 hours.  65-66

In the area of glaucoma management the following statement comes from a 2011 article. “We must also remember the side effects of 'medications' (e.g., marijuana, alcohol) before promoting as remedy for glaucoma. In current armamentarium of glaucoma management, ACT cannot substitute the conventional treatment available to lower IOP.” 67 Another report cited that a single 5 mg sublingual dose of Delta-9-THC reduced the IOP temporarily for four hours and was well tolerated by most patients. Sublingual administration of 20 mg CBD did not reduce IOP, whereas 40 mg CBD produced a transient increase IOP rise. 68 In one case report involving one patient, marijuana acted as a last-line therapy for two reasons: the patient was clearly intolerant of other medications, and other medications were not efficacious enough. Smoking marijuana cigarettes combined with the ingestion of 1 or 2 marijuana cookies reduced IOP from 30 mmHg to 15 mmHg. 69

With the potential side effects of inhaled and ingested cannabinoids, it may be postulated that the local application would be of benefit.  However, it appears that to this point the topical application of cannabinoid extracts are limited as they are highly lipophilic with low aqueous solubility.  70-78

The American Glaucoma Society (AGS) states that “although marijuana can lower the intraocular pressure, the side effects and short duration of action, coupled with the lack of evidence that its use alters the course of glaucoma, preclude recommending this drug in any form for the treatment of glaucoma at the present time.” 79

The Canadian Ophthalmological Society does not support the medical use of marijuana for the treatment of glaucoma due to the short duration of action, the incidence of undesirable psychotropic and other systemic side effects and the absence of scientific evidence showing a beneficial effect on the course of the disease. 80

The National Eye Institute (NEI) statement includes the following. “Studies in the early 1970s showed that marijuana, when smoked, lowered intraocular pressure (IOP) in people with normal pressure and those with glaucoma. In an effort to determine whether marijuana, or drugs derived from marijuana, might be effective as a glaucoma treatment, the National Eye Institute (NEI) supported research studies beginning in 1978. These studies demonstrated that some derivatives of marijuana transiently lowered IOP when administered orally, intravenously, or by smoking, but not when topically applied to the eye.

However, none of these studies demonstrated that marijuana -- or any of its components -- could lower IOP as effectively as drugs already on the market. In addition, some potentially serious side effects were noted, including an increased heart rate and a decrease in blood pressure in studies using smoked marijuana.”


Marijuana is a very effective method of controlling glaucoma with minimal side effects.  This little “fact” was investgated herein.


After assessing all of the available literature it does appear that marijuana can lower IOP for the management of glaucoma but the effects appear to last only about three to four hours.  To equal the sustainability of a typical topical prostaglandin the patient would have to consume or inhale the drug 6 to 8 times per day and the potential side effects to the body and to the brain would outweigh the benefits.  That is not to say that there is no potential with the compound.  There is evidence that there may be characteristics of the cannabinoid components of marijuana that are neuroprotective in nature.  82-88

From “The only marijuana currently approved at the Federal level for medical use is Marinol, a synthetic form of tetrahydrocannabinol (THC), the most active component of marijuana. It was developed as an antiemetic (an agent that reduces nausea used in chemotherapy treatments), which can be taken orally in capsule form. The effects of Marinol on glaucoma are not impressive.”

Ben Harper sings Burn One Down.  I love the artist but am not quite sure I like the message after looking at the issue of marijuana and glaucoma.

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About the Author(s)

Larry J Alexander OD FAAO

Larry J Alexander OD FAAO

Dr. Alexander (1948-2016) was a 1971 graduate of Indiana University School of Optometry. He served in the US Navy then served as a Professor at the University of Alabama Birmingham School of Optometry. Larry contributed to a number of chapters in textbooks and has published three editions of Primary Care of the Posterior Segment, as well as contributed to the professional literature. He also lectured extensively in the area of ocular and systemic disease. His areas of special interest included dysfunctional tear syndrome, glaucoma and macular degeneration.  His lessons are the basis for this site and he will be dearly missed. 

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