In 2010 a study was reported by C. Gagliano and colleagues from the Ophthalmology department, Catania University, Catania, Italy. Purpose of the study was to investigate the role of palmitoylethanolamide (PEA) in reducing eye pressure (IOP) in patients with primary open glaucoma (POAG) or ocular hypertension (OHT) who already received in topical anti-hypertensive therapy. Visual acuity, visual field, vital signs, and potential psychotropic effects were also measured.
The study was single blinded and placebo-controlled, using a cross-over design; 42 patients with POAG or OHT treated with topical anti-hypertensive drugs, were randomly entered in to the study.
Either PEA 300 mg or placebo was given twice daily. IOP value was evaluated at baseline, 30 and 60 days (at 8 am, 12 am, 4 pm and 8 pm) were measured. PEA treated patients underwent an untreated washout period of 30 days, after which baseline IOP was measured. Patients were then treated with the opposite dosing regimen for 60 days and IOP measurements were repeated.
Results of palmitoylethanolamide on ocular pressure
On day 30, mean reductions in IOP from baseline were 3.39 ± 0.19 SD mmHg and 1.03±1.1 mmHg for the PEA treated group and placebo group respectively (IC 95%
t=7.050 (20 df) P<0.001). On day 60, mean reductions in IOP from baseline were 3.41±0.21 mmHg and 0.02 ± SD 0.25 mmHg for the PEA treated group and placebo group respectively (IC 95% t=6.120 (20 df) P<0.001). Vital signs, visual acuity and visual field were not significantly changed. No adverse events or side effects were reported in both groups.
Conclusions of authors:
The ocular hypertension patients under treatment with topical anti-hypertensive drugs had a further significant decrease in IOP after 30 and 60 day-treatment with PEA, 300 mg twice daily, in comparison with the same group of patients likewise treated with topical drugs and placebo. PEA was well tolerated and safe. No side effects were reported in PEA treated group.