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).
Internet-based cross-sectional study SUBJECTS/PARTICIPANTS/CONTROLS: N/A METHODS: Google and two social media platforms (Facebook, Youtube) were utilized 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.
The quality of the content was graded by two independent graders using a previously validated Sandvik score and 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.
The above 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 was 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) respectively for Google, Facebook, and Youtube. ANOVA analysis showed statistically significant differences in Sandvik (p=0.01) and risk scores (p<0.0001) across the three 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 significantly higher content quality score, lower risk score, and was less likely to recommend MC use in glaucoma.
Despite American Academy of Ophthalmology, Canadian Ophthalmological Society, and American Glaucoma Society statements against medical cannabis use in glaucoma patients, 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.

Copyright © 2020. Published by Elsevier Inc.