Clinical trial for the evaluation of neuroprotective effects of palmitoylethanolamide: Visual Field and Pattern-ERG

Purpose To study the effects of palmitoylethanolamide (PEA), a fatty acid ethanolamide, on IOP, visual field and pattern-ERG in glaucoma patients. Methods 36 glaucoma (POAG) patients treated topically with timolol 0.5% were randomly assigned to either orally PEA 300 mg/die 2 times daily (Group A) or placebo (Group B). The patients had at least 5 VF tests using the Humphrey Visual Field Analyzer (Threshold 30-2) for more than a 2-year period before PEA treatment. At baseline and after 6, 12, 18, 24 months of treatments we evaluated in both groups the change of progression rate of visual field using mean deviation (MD), and pattern standard deviation (PSD). Comparison of means was performed with the paired t-test.The involvement of retinal ganglion cells (RGCs) were investigated using pattern electroretinograms (PERG) recorded twice a year in 36 glaucoma patients over at least 2 years. Results Significative IOP reduction was observed in the Group A, PEA treated patients (16.94 ± 3.96 vs. 13.8 ± 3.24 mm Hg; P < 0.001).A statistically significant difference in the MD was found between the two groups (PEA treated, -2.9 dB±2.93; Placebo treated, -8.55 dB±6.51 P=0.001). Furthermore, the change in PSD reached statistical significance: PEA 2.63 dB ±1.47; Placebo 6.59 dB ±6.51 P=0.002. PERG amplitude decreased significantly (P<0.01) in patients treated with placebo compared with PEA. PEA tablets continued to be safe and well-tolerated, with no drug-related adverse events. Conclusion These findings show substantial clinical benefits of PEA treatment in POAG patients:reduction of IOP as well as significative improvement in visual field and PERG.