Omega-3 ALA Helps Combat Dry Eye Symptoms
Omega 3 ALA: a help against dry eye syndrome
Omega-3 ALA (alpha-linolenic acid) reduces the symptoms of inflammation from dry eye (also known as dry eye syndrome or hypolacrima). The potential of this fatty acid in treating this condition was suggested by a study conducted on mice and published in Archives of Ophthalmology1. According to the authors, led by Reza Dana from the Schepens Eye Research Institute in Boston (USA), the results open the way to a new topical therapy to reduce the inflammatory phenomena associated with this condition.
Dry eye or hypolacrima: when the eye doesn’t cry enough
Dry eye syndrome is a disorder more frequent after age 40 that particularly affects:
- contact lens wearers;
- people who spend a lot of time at the computer;
- people frequently exposed to sun and wind.
The sensation of having a foreign body in the eye is one of the symptoms of dry eye. The problem behind this sensation is the reduction in tear production or an alteration of their composition. Indeed, if tears fail to keep the eye surface sufficiently moist, the outermost layer of the eye (the cornea) dehydrates and consequently becomes irritated.
Symptoms of dry eye
Symptoms of dry eye include:
- a sensation similar to having sand in the eyes;
- redness;
- pain;
- burning;
- discomfort when exposed to light;
- formation of wounds (in more severe cases).
Staining the eye surface with fluorescein is a way to visualize the presence of these lesions. The number of some immune system cells (CD11b+) as well as the expression of genes involved in immunity increase in the affected eye. Another marker of dry eye syndrome is the expression of several molecules involved in inflammatory processes:
- TNF-alpha;
- interferon gamma;
- interleukins IL-1 alpha, IL-2, IL-6, and IL-10.
The effect of Omega-3
Through an experiment on mice, Dana and colleagues showed that the direct application on the cornea of a product containing Omega-3 ALA reduces the ability of fluorescein to stain the eye as well as the number of CD11b+ cells. Treatment with ALA also reduces:
- the expression of IL-1 alpha in the cornea;
- the expression of TNF-alpha in the cornea and conjunctiva, the membrane lining the inside of the eyelids.
This effect appears to be exclusive to Omega-3. Indeed, the application of linoleic acid (LA), a fat belonging to the Omega-6 group, does not achieve the same results observable with ALA. Even the combined use of ALA and LA does not provide the same benefits as applying a product containing only Omega-3.
Omega-3 against inflammation
These results confirm the anti-inflammatory action of Omega-3 on the body. In particular, the usefulness of this function in relation to dry eye syndrome is also confirmed by research showing that a diet rich in these nutrients prevents symptoms of the disorder.
Source:
1. Rashid S, Jin Y, Ecoiffier T, Barabino S, Schaumberg DA, Dana MR, “Topical omega-3 and omega-6 fatty acids for treatment of dry eye”, Arch Ophthalmol. 2008 Feb;126(2):219-25.
