Marijuana and Glaucoma: A Social Media Content Analysis

Ophthalmol Glaucoma. 2021 Jul-Aug;4(4):400-404. doi: 10.1016/j.ogla.2020.11.004. Epub 2020 Nov 24.


Purpose: This study analyzes the content quality and characteristics of the most popular and highly ranked search results on the internet related to glaucoma and medical cannabis (MC).

Design: Internet-based, cross-sectional study.

Participants: Not applicable.

Methods: Google and 2 social media platforms (Facebook, YouTube) were used to identify online information most accessible to patients. Search criteria included "glaucoma" AND "marijuana" or "cannabinoid" or "CBD." The top 20 Google search and YouTube results for each search term and the posts from the top 9 patient-based glaucoma Facebook groups were aggregated and analyzed using the search criteria.

Main outcome measures: The quality of the content was graded by 2 independent graders using a previously validated Sandvik score and previously reported risk score. The differing values were resolved by a final grader. Additional analysis included whether the source was professional (by physician or medical organization) or shared an opinion on MC (pro, mixed, or against) use in glaucoma.

Results: This search resulted in an aggregate of 51 websites on Google, 126 posts from Facebook groups, and 37 videos on YouTube. The mean (± standard deviation) Sandvik score and risk score were 11.0 (±2.23), 10.2 (±1.12), 10.6 (±1.89) and 0.27 (±0.49), 0.46 (±0.62), 0.97 (±0.90) for Google, Facebook, and YouTube, respectively. Analysis of variance showed statistically significant differences in Sandvik (P = 0.01) and risk (P < 0.0001) scores across the 3 platforms. A significant portion of online material was pro-MC use in the setting of glaucoma (24% of Google, 59% of YouTube, and 21% of Facebook results). Professional content had a significantly higher content quality score and a lower risk score, and was less likely to recommend MC use in glaucoma.

Conclusions: Despite American Academy of Ophthalmology, Canadian Ophthalmological Society, and American Glaucoma Society statements against MC use in patients with glaucoma, a significant portion of online material recommends its use. With the wide variation in quality and content of online information, it is important for physicians to be aware of the different platforms and opinions that are readily available to patients.

Keywords: CBD; Glaucoma; Marijuana; alternative medicine; alternative treatment; cannabinoid; internet; medical cannabis; medical marijuana; online content.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Canada
  • Cannabis*
  • Cross-Sectional Studies
  • Glaucoma*
  • Humans
  • Social Media*
  • United States