People suffering from glaucoma are strongly influenced to try marijuana as an alternative treatment even though research has shown its possible benefits are overestimated, a study indicates.
Although research suggests marijuana has limited therapeutic value in glaucoma treatment, many patients appear to willingly try it, the study found.
That willingness has been driven in part by the legalization of marijuana for either medical or recreational use in 23 states and the District of Columbia.
"Understanding [patients'] intentions will become even more important as states continue to legalize marijuana for recreational use (currently Washington, D.C., and 4 other states), as patients with glaucoma will then have access to marijuana without the need for a physician to prescribe this drug," suggest the authors of a study appearing in the Journal of the American Medical Association.
Although proponents of legalization often cite a 1999 report by the Institute of Medicine on the possible therapeutic effects of marijuana regarding the number of medical conditions, including glaucoma, patients need to understand its specific effects on the eye condition, the researches argue.
Some studies have found that marijuana can relieve intraocular pressure, the main symptom of glaucoma. Glaucoma is a condition where increased pressure within the eyeball damages the optic nerve and causes a gradual loss of sight.
However, while marijuana may relieve some effects of glaucoma for 3 or 4 hours, dosages eight to 10 times per day would be needed for a "sustained therapeutic effect," the researchers wrote.
In addition, only around 60 percent of people using marijuana for glaucoma have experienced any reduction in intraocular pressure, they note.
The study results "suggest a need for more education on this topic for ophthalmologists to be able to protect patients with glaucoma against the increased acceptability among the public of using marijuana based on false perceptions of its therapeutic value in glaucoma therapy," wrote study lead author David A. Belyea from the Department of Ophthalmology at George Washington University.
That education should aim at changing unrealistic expectations patients may be putting on marijuana as an alternative treatment and improving their satisfaction with current glaucoma management efforts, the researchers said.
As marijuana is increasingly being legalized, there is a significant gap between what research has shown it may be capable of in the treatment of glaucoma and a spreading popular expectation of what it can do.
"This strong public-driven shift toward legalization of medical marijuana seems to clash with the relatively weak scientific evidence supporting its therapeutic use, particularly for treatment of glaucoma," the researchers wrote in an editorial accompanying their published study.
In addition to better education efforts, doctors need to work with patients on several levels. They must engage in the patient's support system, since many elderly patients prefer making decisions with the help of family and friends. Lastly, they should borrow patient-centered techniques from other medical specialties such as using peer educators and patient advisory groups to boost how satisfied patients are and their adherence to treatment plans.