A multicentre, double‐masked, randomized, controlled trial assessing the effect of oral supplementation of omega‐3 and omega‐6 fatty acids on a conjunctival inflammatory marker in dry eye patients

. Purpose: To determine whether oral supplementation with omega‐3 and omega‐6 fatty acids can reduce conjunctival epithelium expression of the inflammatory marker human leucocyte antigen‐DR (HLA‐DR) in patients with dry eye syndrome (DES). Methods: This 3‐month, double‐masked, parallel‐group, controlled study was conducted in nine centres, in France and Italy. Eligible adult patients with mild to moderate DES were randomized to receive a placebo containing medium‐chain triglycerides or treatment supplement containing omega‐3 and omega‐6 fatty acids, vitamins and zinc. Treatment regimen was three capsules daily. Impression cytology (IC) was performed at baseline and at month 3 to assess the percentage of cells expressing HLA‐DR and to evaluate fluorescence intensity, an alternate measure of HLA‐DR. Dry eye symptoms and objective signs were also evaluated. Analyses were performed on the full analysis set (FAS) and per‐protocol set (PPS). Results: In total, 138 patients were randomized; 121 patients with available IC were included in the FAS, and of these, 106 patients had no major protocol deviations (PPS). In the PPS, there was a significant reduction in the percentage of HLA‐DR‐positive cells in the fatty acids group (p = 0.021). Expression of HLA‐DR as measured by fluorescence intensity quantification was also significantly reduced in the fatty acids group [FAS (p = 0.041); PPS (p = 0.017)]. No significant difference was found for the signs and symptoms, but there was a tendency for improvement in patients receiving the fatty acids treatment. Conclusion: This study demonstrates that supplementation with omega‐3 and omega‐6 fatty acids can reduce expression of HLA‐DR conjunctival inflammatory marker and may help improve DES symptoms.