Generally
speaking we tout the potential of marijuana, advocating its medical
advantages left, right, and center. We praise its benefits for pain
reduction, epilepsy, nausea, autism, MS, anorexia, and countless other
conditions – the list is positively exhaustive. And yet, we would not
advocate for marijuana unequivocally. One case where we do not outright
recommend marijuana’s medicinal properties is with glaucoma.
Glaucoma
is a condition where increased pressure within the eyeball causes damage
to the optic nerve, risking and often causing blindness, especially
among the elderly. Several advocates of medicinal marijuana cite
small-study or anecdotal evidence that cannabis can lower intraocular
pressure (IOP) in people with glaucoma. However, these products are
less effective than safer prescription drugs.
Side Effects
In order
to produce a clinically-relevant pressure reduction on IOP, frequent
inhalation is required because the effect only lasts a few hours. This
means one would need to smoke a joint every 3 hours. The number of
significant side effects generated by long-term oral use of marijuana or
long-term inhalation of marijuana smoke can make it a poor choice in
the treatment of glaucoma, a chronic disease requiring proven and
effective treatment.
The only
marijuana currently approved at the US-federal level for medical use is
Marinol, a synthetic form of tetra hydrocannabinol (THC) – the most
active component of marijuana and the one which produces the “high.”
Marinol was developed as an antiemetic (an agent that reduces nausea
used in chemotherapy treatments), which can be taken orally in capsule
form.
But it
turns out that the effects of Marinol in general, and on glaucoma in
particular, are not impressive compared to the real thing. Yet in terms
of glaucoma, no studies have shown that marijuana or any of its
approximately 400 chemical components can safely and effectively lower
intraocular pressure better than the variety of drugs currently on the
market. In addition, according to the Glaucoma Research Foundation, while marijuana might lower intraocular pressure, it also lowers blood pressure, which in turn could provide less blood to the optic nerve.
IOC
pressure notwithstanding, the issue of pain still remains. That is to
say, while medical marijuana might not help with curing glaucoma, it can
provide a great sense of pain-relief comfort to glaucoma sufferers.
Part of the reason for legalizing marijuana is to allow adults to make
the best choices. Glaucoma, it seems, is a prime example of such a
dilemma, best discussed with your medical marijuana supportive care
provider.
