Association between cannabis use and ocular inflammatory disease: a large-scale cohort study

Objective: Cannabis use has increased substantially worldwide, yet its association with inflammatory eye diseases remains poorly understood. This study evaluated whether cannabis users have higher risk of developing uveitis and related inflammatory ocular conditions compared to non-users. Methods: We conducted a retrospective cohort study using the TriNetX Global Collaborative Network database. Adult patients with documented cannabis-related disorders were propensity score-matched 1:1 to patients with no cannabis use, excluding individuals with prior diagnoses that could independently cause uveitis. The primary outcome was the incidence of any uveitis. Secondary outcomes included specific uveitis subtypes, retinal vasculitis, and choroidal degeneration, assessed starting 1 year after cohort entry. Kaplan-Meier survival analysis and Cox proportional hazards models compared outcomes between groups. Results: After propensity matching, 1,156,655 cannabis users were compared with 1,156,655 matched non-users. Cannabis use was associated with significantly increased risk of any uveitis (hazard ratio [HR] 1.8, 95% confidence interval [CI] 1.65–1.95, p < 0.0001). Specific uveitic conditions showed higher relative risks: panuveitis demonstrated the strongest association (HR 3.64, 95% CI 2.24–5.91, p < 0.0001), followed by choroidal degeneration (HR 3.29, 95% CI 1.74–6.23, p < 0.0001) and retinal vasculitis (HR 3.27, 95% CI 1.81–5.89, p < 0.0001). Conclusions: Cannabis use was associated with statistically and clinically significant increased risk of ocular inflammatory diseases, particularly those affecting the posterior eye segment. These findings have important implications for ophthalmologic screening and patient counseling as cannabis use becomes more widespread.