An assessment of the prevalence of cannabis use in eye clinic patients and its implications on glaucoma diagnosis and management.

PURPOSE: Intraocular pressure (IOP) is a major clinical marker used to diagnose glaucoma and monitor its treatment. Marijuana use can confound IOP measurements by temporarily lowering the IOP, potentially leading to missed diagnoses of glaucoma or a false sense of effective treatment. Therefore, factors that may affect diagnosis or treatment of glaucoma need to be characterized and considered. We aim to assess the prevalence of cannabis use among patients presenting for an eye examination. METHODS: A survey was administered to 134 patients arriving for their regular ophthalmic appointments, from Oct 2022 to Jan 2023 and Jul 2024-Aug 2024 in four eye clinics at the University of Minnesota (UMN). RESULTS: Among study patients, 15.7% reported recent use of marijuana (< 1 month), 8.2% described themselves as regular users, and 4.5% of patients reported using it every day. Just under half (44.2%) of glaucoma patients indicated they were interested in using marijuana for their glaucoma. Patients that used marijuana less than 24 h from their eye exam were significantly more likely to know that marijuana decreases intraocular pressure (IOP) (p = 0.02). Beliefs that marijuana is effective (p = 0.016), lowers IOP (p = 0.011), and has fewer side effects than glaucoma medications (p = 0.014) were predictive of interest in marijuana use. In contrast, beliefs that marijuana has negative physical (p = 0.041) and mental (p = 0.003) health effects were predictive of disinterest in use. CONCLUSION: These findings indicate need for increased patient screening for recent marijuana use so ophthalmologists may contextually assess IOP and educate patients on marijuana's effects on the diagnosis and treatment of glaucoma.