Wednesday, February 13, 2008

Study: Topical Omega-3 and Omega 6

Interesting. Maybe. But this is one of those studies that leaves me groaning. Like so many treatments, this is one where I can oh so easily visualize a small stampede of patients heading for the compounding pharmacy to get some new goop to try out, especially after all the recent discussions on Dry Eye Talk about application of various lipids on or near the eyes.

To all of whom my only comment is this:

Unless you are a small rodent that was recently injected with subcutaneous scopolamine to induce ocular dryness, are satisfied with experiencing 2 to 10 days of improved clinical signs of dry eye, and don't mind being euthanized within a few days, don't waste your time, money and emotional energy trying to personally replicate these results.

According to MedPage Today, Dr. Dana says "...clinical trials are being planned to see whether the results translate to restore the tear film in patients with dry eye. If successful, he said, topical application of fatty acids could alter the method by which this common condition is treated."

Frankly, I can hardly imagine a longer leap than from improved SIGNS in mice with some kind of artificially induced superficial dryness to improved SIGNS AND SYMPTOMS in humans. Wake me up when the double blind randomized human studies are complete, please.

If I sound overly skeptical, forgive me. My problem is not with what the authors are doing but with the ever-greater hype surrounding anything akin to a new idea in dry eye treatment. For goodness' sakes, even the ancient Greeks put fat in the eye for xerophthalmia.

Topical omega-3 and omega-6 Fatty acids for treatment of dry eye.
Rashid S, Jin Y, Ecoiffier T, Barabino S, Schaumberg DA, Dana MR
Arch Ophthalmol. 2008 Feb;126(2):219-25

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-1alpha and tumor necrosis factor alpha (TNF-alpha) expression; and conjunctival IL-1alpha, TNF-alpha, interferon gamma, 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-1alpha and TNF-alpha, and conjunctival TNF-alpha.
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.

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