US researchers found cannabis use moderately lowered the risk of proliferative vitreoretinopathy (PVR) development in patients who underwent retinal detachment (RD) repair.

The retrospective cohort study used the electronic health records of 1,193 matched patients, with a mean age of 53.2 years. At six months, patients with concomitant cannabis use with RD repaired by any method had a reduced risk, compared with controls, of developing subsequent PVR (2.10% vs 4.36%) and requiring complex RD repair (3.10% vs 5.03%). Similar results were observed at one year for both outcomes, said researchers.

“While this protective association with cannabis use could be due to the population using it rather than an effect of the cannabis itself, the findings suggest cannabis use might have a role in reducing PVR development,” said researchers writing in JAMA Ophthalmology. Intervention trials would be needed to try to control for confounding factors, they added.