A survey of patients with glaucoma in Washington, D.C., showed that the perception of the legality and acceptability of marijuana use was significantly associated with intentions to use marijuana for the treatment of glaucoma, even though research has indicated it is of limited benefit, according to a study published online by JAMA Ophthalmology.

It is estimated that 2.2 million adults in the United States are affected by glaucoma. Alternative therapies are being explored but have not shown promise, including marijuana. Previous research has shown several limitations associated with its use as a treatment for glaucoma. Driven mainly by public support, 21 states and the District of Columbia have legalized the medical use of marijuana, citing mainly the 1999 Institute of Medicine report that found possible therapeutic benefits for the use of marijuana in various debilitating medical conditions, including glaucoma. Given these legal changes, glaucoma physicians are approached with patient inquiries about treatment of their glaucoma with this alternative therapy.

David A. Belyea, M.D., M.B.A., of the George Washington University School of Medicine and Health Sciences, Washington, D.C., and colleagues examined factors associated with intentions by patients to use marijuana as a treatment for glaucoma. The study included a survey of patients with glaucoma or suspected to have glaucoma at a clinic in Washington, D.C., between February and July 2013. The survey assessed demographics, perceived severity of glaucoma, prior knowledge about marijuana use in glaucoma, past marijuana use, perceptions toward marijuana use (legality, systemic adverse effects, safety and effectiveness, and false beliefs), satisfaction with current glaucoma management, relevance of treatment costs, and intentions to use marijuana for glaucoma.

Of the 334 patients who were invited to participate in the study, 204 (61 percent) completed the survey. Analysis of responses indicated that perceptions of legality of marijuana use, false beliefs regarding marijuana, satisfaction with current glaucoma care, and relevance of marijuana and glaucoma treatment costs were significantly associated with intentions to use marijuana for glaucoma treatment.

“This study contributes to filling the gap in our knowledge about patients’ perceptions toward using marijuana for glaucoma and their intentions to seek this therapeutic alternative. Understanding these 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,” the authors write.

“Our findings suggest a need for more education on this topic to protect patients with glaucoma against the increased acceptability among the public toward using marijuana based on false perceptions of its therapeutic value in glaucoma therapy”

Commentary: Shaping Patients’ Perspective of Medical Marijuana for Glaucoma Treatment

Belyea and colleagues have identified an intricate web of factors that influence the perception held by patients with glaucoma about medical marijuana, write Eve J. Higginbotham, S.M., M.D., of the University of Pennsylvania, Philadelphia, and Lenora A. Higginbotham, M.D., of Johns Hopkins Hospital, Baltimore, in an accompanying commentary.

“Altering this complex web of beliefs, misconceptions, satisfaction, and discontent requires an equally intricate patient-centered approach if physicians who treat patients with glaucoma are to effectively influence patient perception and transcend the clash between scientific evidence and popular culture.”