COMMENTARY

There's Nothing Fishy About Omega-3 Fatty Acids for Dry Eye Syndrome

Robert H. Graham, MD

Disclosures

September 01, 2009

In This Article

Dry Eye Syndrome: Treatments

Treatment Mainstays of Dry Eye Syndrome

The mainstay of treatment for aqueous tear deficiency is to rehydrate and lubricate the ocular surface with topical lubricants. Lubricant eye drops (artificial tears), lubricant eye gels, and lubricant eye ointments are all available over the counter to help increase or maintain lubrication of the ocular surface and decrease symptoms. By supplementing the available tears, lubricant eye drops help to rehydrate the ocular surface and to protect it from dessication.

Another treatment option is the insertion of punctal plugs. Punctal plugs help prevent drainage of the tear film down the lacrimal drainage system, thereby keeping more of the tear film on the ocular surface and rendering it less prone to suffer ill effects from dryness. However, if the tear film is unhealthy in any way, such as having proinflammatory mediators, the punctal plugs may actually worsen the patient's symptoms.

Anti-inflammatory therapies, such as topical cyclosporine, may help increase production of aqueous tears by decreasing the infiltration of inflammatory cells into the lacrimal glands. With increased production of aqueous tears and fewer inflammatory compounds on the ocular surface, patients are less prone to have DES symptoms.

The critical role of the meibomian glands in DES is becoming more and more appreciated.[4] In patients with meibomian gland dysfunction, tetracycline and its analogues doxycycline and minocycline have helped to stabilize the lipid layer of the tear film, thereby improving evaporative dry eyes. They work by decreasing the bacterial load on the eyelid; with fewer bacteria, there is less degradation of the lipids produced by the meibomian glands, and less inflammatory waste is produced.

Omega-3 Fatty Acids as Treatment for Dry Eye Syndrome

Similarly, the essential omega-3 fatty acids, such as eicosapentaenoic acid (EPA) and docosahexanoic acid (DHA) found in fish oil and alpha-linoleic acid (ALA) in flax seed oil, are also thought to improve evaporative dry eye. Omega-3 fatty acids are believed to competitively inhibit the production of proinflammatory mediators, such as interleukin-1 and tumor necrosis factor-alpha. With fewer proinflammatory compounds available, the ocular tear film is thought to be able to better promote a healthy ocular surface. A higher intake of omega-3 fatty acids has been associated with a decreased incidence of DES in women.[5]

Some relatively common side effects of omega-3 supplementation (especially fish oil supplements) include "fish oil burps," upset stomach, and bad aftertaste. These can usually be alleviated by taking supplements with enteric coatings to delay the release of the oils until they are out of the stomach and in the lower intestine.

Widely available over the counter, omega-3 fatty acids are commonly found in a gel capsule and are usually provided in an ethyl ester form instead of their naturally occurring triglyceride form. This ethyl ester form is easier to work with during industry processing and distillation to remove contaminants and impurities. Unfortunately, the bioavailability of ethyl ester form is reduced to as low as 20% (up to 60% with a high-fat meal). This compares poorly with the triglyceride form's absorption of 69% (increasing to 90% with a high-fat meal).[6] This increased bioavailability results in 50% more plasma EPA and DHA when the acids are administered as a triglyceride rather than an ethyl ester.[7]

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