Systemic omega-6 essential fatty acid treatment and PGE1 tear content in Sjogren's syndrome patients

PURPOSE. To determine the effect of oral omega-6 essential fatty acids on PGE(1) tear content and signs and symptoms of ocular discomfort in patients with Sjogren's syndrome (SS). METHODS. This randomized, double-masked, controlled, clinical trial involved 40 patients with primary SS, divided into two groups: group 1: 20 patients (18 women, 2 men; mean age, 36.9 +/- 7.9 years [SD]) treated for 1 month with linoleic acid (LA; 112 mg), and gamma-linolenic acid (GLA; 15 mg) administered twice daily; group 2: 20 patients (19 women, 1 man; mean age, 36.3 +/- 5.5 years) treated twice daily with placebo. Patients underwent three examinations: at baseline (T0), after 1 month of treatment (T1), and 15 days after suspension of treatment (T2). At each examination, the following tests were performed: tear sampling (2 mu L) from the inferior meniscus, tear break-up time (BUT), fluorescein stain of the ocular surface, and tear basal secretion. A symptom score was also obtained at each examination. PGE(1) was evaluated by enzyme immunoassay. The primary efficacy variable was PGE1 content of tears. RESULTS. The tear PGE(1) levels were significantly increased in group 1 at T1 versus T0 (PGE(1) level: T0, 44 +/- 5.4 ng/mL; T1, 58.3 +/- 5.5 ng/mL; P < 0.01 versus T0 and group 2 at T1). At examination T2, a statistically significant reduction of PGE(1) levels toward baseline was observed (45.7 +/- 5.2 ng/ mL; P < 0.01 versus T1). A statistically significant reduction of symptom score was observed in group 1 at examination T1 (P < 0.01 versus T0 and group 2 score). At examination T2, the symptom score was significantly higher than T1 but remained lower than T0. The corneal fluorescein stain in group 1 showed a statistically significant improvement at examination T1 versus T0 and group 2 (P < 0.01). This improvement was also present at T2 (P < 0.02). No statistically significant differences were found for the other tests. No statistically significant changes were observed in the patients in group 2 at all examination time points. CONCLUSIONS. Omega-6 administration increases the PGE(1) levels in tears of patients with SS and improves ocular surface signs and symptoms of ocular discomfort.