Cannabis Lowered Eye Pressure but Was Linked to Earlier Glaucoma Diagnosis

In a large UK cohort, cannabis users who used 100+ times developed glaucoma about 10 years younger than non-users, despite cannabis being associated with lower eye pressure.

Lehrer, S et al.·Journal francais d'ophtalmologie·2022·Moderate EvidenceRetrospective Cohort
RTHC-03996Retrospective CohortModerate Evidence2022RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Retrospective Cohort
Evidence
Moderate Evidence
Sample
Not reported

What This Study Found

Heavy cannabis users (100+ times) were diagnosed with glaucoma approximately 10 years earlier than never-users. Cannabis use modestly lowered intraocular pressure but did not increase overall glaucoma risk. The earlier age of diagnosis was independent of IOP effects and cigarette smoking.

Key Numbers

~10 years younger glaucoma diagnosis in 100+ time users; cannabis effect on glaucoma incidence not significant (P=0.662); IOP significantly lower in 11-100 time users

How They Did This

Retrospective analysis of UK Biobank data examining relationships between cannabis use frequency, intraocular pressure, and glaucoma diagnosis age, controlling for cigarette smoking and age.

Why This Research Matters

Cannabis has long been discussed as a potential glaucoma treatment because it lowers eye pressure. This study complicates that narrative by showing that despite lower IOP, frequent cannabis users developed glaucoma earlier.

The Bigger Picture

The finding that cannabis lowers eye pressure yet is associated with earlier glaucoma challenges the assumption that IOP reduction alone is protective. Other mechanisms of glaucoma damage may be at play.

What This Study Doesn't Tell Us

Self-reported cannabis use. UK Biobank participants may not represent the general population. Cannot establish causation from observational data.

Questions This Raises

  • ?Through what mechanism might cannabis accelerate glaucoma development while simultaneously lowering IOP?
  • ?Could cannabis smoke contain compounds that damage the optic nerve through pathways unrelated to eye pressure?

Trust & Context

Key Stat:
~10 years earlier glaucoma diagnosis in heavy users
Evidence Grade:
Large population cohort (UK Biobank) with robust statistical controls, but observational design limits causal conclusions.
Study Age:
Published in 2022
Original Title:
Cannabis smoking and glaucoma in the UK Biobank cohort.
Published In:
Journal francais d'ophtalmologie, 45(4), 423-429 (2022)
Authors:
Lehrer, S(2), Rheinstein, P H(2)
Database ID:
RTHC-03996

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled Trial
Cohort / Case-ControlFollows or compares groups over time
This study
Cross-Sectional / Observational
Case Report / Animal Study

Looks back at existing records to find patterns.

What do these levels mean? →

Frequently Asked Questions

Does cannabis help with glaucoma?

This study found a paradox: cannabis lowered eye pressure (which should help) but was associated with earlier glaucoma development. The authors concluded that cannabis-based glaucoma treatments are "of questionable value."

How much younger were cannabis users when diagnosed with glaucoma?

Users who consumed cannabis 100+ times were diagnosed with glaucoma approximately 10 years earlier than those who never used cannabis, and this was independent of eye pressure effects.

Read More on RethinkTHC

Cite This Study

RTHC-03996·https://rethinkthc.com/research/RTHC-03996

APA

Lehrer, S; Rheinstein, P H. (2022). Cannabis smoking and glaucoma in the UK Biobank cohort.. Journal francais d'ophtalmologie, 45(4), 423-429. https://doi.org/10.1016/j.jfo.2021.12.012

MLA

Lehrer, S, et al. "Cannabis smoking and glaucoma in the UK Biobank cohort.." Journal francais d'ophtalmologie, 2022. https://doi.org/10.1016/j.jfo.2021.12.012

RethinkTHC

RethinkTHC Research Database. "Cannabis smoking and glaucoma in the UK Biobank cohort." RTHC-03996. Retrieved from https://rethinkthc.com/research/lehrer-2022-cannabis-smoking-and-glaucoma

Access the Original Study

Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.

This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.