The aim of the present work was the evaluation of a topic application of cannabinoids in 5 patients affected by late stage open angle glaucoma (OAG) in which both surgical and medical therapies had failed to decrease the intraocular pressure (IOP) to acceptable levels, and were not suitable to further surgical intervention. Eye drops were formulated with Bediol (containing low amounts of tetrahydrocannabinol [THC] and cannabidiol [CBD]), and with Bedrocan (containing higher amounts of THC and lower amounts of CBD). Patients were treated first with Bediol eye drops for 30 days, and after a one-month washout period, they were treated with Bedrocan eye drops for a further 30 days. Four patients did not show any response to both products, while a fifth patient, affected by glaucoma secondary to Fuchs heterochromic iridocyclitis (a rare form of uveitis), showed a relevant antinflammatory effect and IOP decrease in the affected eye. These results suggest a use of THC as an antinflammatory agent in cases of glaucoma secondary to inflammatory events.