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 Sjögren'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 microL) 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. PGE1 was evaluated by enzyme immunoassay. The primary efficacy variable was PGE1 content of tears.

RESULTS:
The tear PGE1 levels were significantly increased in group 1 at T1 versus T0 (PGE1 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 PGE1 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 PGE1 levels in tears of patients with SS and improves ocular surface signs and symptoms of ocular discomfort.

PMID: 16303936

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