Marijuana Use Among Patients With Glaucoma in a City With Legalized Medical Marijuana Use.

IMPORTANCE

Previous research has shown several limitations associated with the use of marijuana as a treatment for glaucoma. However, little is known regarding patients' perceptions toward using marijuana for glaucoma and their intentions to use this therapeutic alternative.

OBJECTIVE

To identify factors among patients with glaucoma that could lead to intentions to use marijuana for treatment.

DESIGN, SETTING, AND PARTICIPANTS: This cross-sectional survey study of 204 patients with glaucoma or suspected to have glaucoma was conducted at an academic-based glaucoma clinic in Washington, DC, between February 1 and July 31, 2013. Patients completed a self-administered survey assessing 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. Medical records were reviewed for disease severity. Data analysis was conducted from September 1, 2013, to September 30, 2015.

MAIN OUTCOMES AND MEASURES

The main outcome was patients' intentions to use marijuana for glaucoma. Multiple linear regression analysis was conducted to identify factors associated with patients' intentions to use marijuana for glaucoma.

RESULTS

Of the 334 patients who were invited to participate in the study, 204 (61.1%) completed the survey. About half the participants were women (104 [51.0]%), and 82 (40.2%) were white. Regression analysis of 204 respondents indicated that perceptions of legality of marijuana use (β, 0.378; 95% CI, 0.205 to 0.444; P < .001), false beliefs regarding marijuana (β, 0.323; 95% CI, 0.236 to 0.504; P < .001), satisfaction with current glaucoma care (β, -0.222; 95% CI, -0.362 to -0.128; P < .001), and relevance of marijuana and glaucoma treatment costs (β, 0.127; 95% CI, 0.008 to 0.210; P = .04) were significantly associated with intentions to use marijuana for glaucoma treatment after controlling for demographic variables, disease severity, and previous marijuana use.

CONCLUSIONS AND RELEVANCE

This study's findings 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. Considering the strong influence of perceptions of the legality of marijuana use on intentions to use this substance as a treatment for glaucoma, patient education might be particularly relevant in states in which marijuana use for glaucoma is legal, as in the case of the current study's setting.