Topical omega-3 and omega-6 fatty acids for treatment of dry eye

Objective: To study the efficacy of topical application of alpha-linolenic acid (ALA) and linoleic acid (LA) for dry eye treatment. Methods: Formulations containing ALA, LA, combined ALA and LA, or vehicle alone, were applied to dry eyes induced in mice. Corneal fluorescein staining and the number and maturation of corneal CD11b⁺ cells were determined by a masked observer in the different treatment groups. Real-time polymerase chain reaction was used to quantify expression of inflammatory cytokines in the cornea and conjunctiva. Results: Dry eye induction significantly increased corneal fluorescein staining; CD11b⁺ cell number and major histocompatibility complex Class II expression; corneal IL-1α and tumor necrosis factor α (TNF-α) expression; and conjunctival IL-1α, TNF-α, interferon γ, IL-2, IL-6, and IL-10 expression. Treatment with ALA significantly decreased corneal fluorescein staining compared with both vehicle and untreated controls. Additionally, ALA treatment was associated with a significant decrease in CD11b⁺ cell number, expression of corneal IL-1α and TNF-α, and conjunctival TNF-α. Conclusions: Topical ALA treatment led to a significant decrease in dry eye signs and inflammatory changes at both cellular and molecular levels. Clinical Relevance: Topical application of ALA omega-3 fatty acid may be a novel therapy to treat the clinical signs and inflammatory changes accompanying dry eye syndrome.