Should tear dysfunction be treated with nutritional supplements?

Nutritional supplements seem to make sense as a treatment of tear dysfunction, according to Marian Macsai, MD. Dr Macsai tempered her assertion with the observation that no objective trials have been performed to support the use of nutritional supplements in patients with tear deficiency.

Dry eye disease has an underlying inflammatory component that results in decreased aqueous tear production and increased evaporative tear loss. Fatty acid metabolism is a hot topic in this regard because omega 3 metabolizes into anti-inflammatory eicosanoids and thrombolytic agents, and omega 6 metabolism is key in the production of arachadonic acid and other inflammatory mediators and platelet aggregators. A shift in the omega 3:omega 6 fatty acids ratio to 2.3:1 from the average American ratio of 10:1, towards omega 3 can lower the overall inflammatory state in the body and decrease risk of clinically diagnosed dry eye, according to Dr Macsai, professor and vice chairwoman, Department of Ophthalmology, Northwestern University, Glenview, US.

"The risk of dry eye decreased by about 30% per additional gram of omega 3 consumed per day in the Women's Health Study," she said. In addition, omega-3 supplementation has a positive effect on asthma, cardiovascular disease, arthritis, depression, and adult-onset diabetes.

Flaxseed oil, which belongs to omega-3 fatty acids, is believed to reduce inflammation by inhibiting tumour necrosis factor-alpha and interleukin-1 beta. Supplementation with fish oil, another hot topic, inhibits the omega 6 pathway. Dr Macsai pointed out that treating patients with Sjögren's syndrome with flaxseed oil, fish oil, and vitamin E significantly improved dry eye and dry mouth symptoms. However, bilberry and evening primrose oil seem to have no significant effects in patients with dry eye.

"Nutritional supplementation probably should be used in patients with dry eye. Vitamin E may or may not be needed. Theoretically, this supplementation makes sense," Dr Macsai said. She noted that the coagulation effect of those nutritional supplements must be kept in mind, however, especially for patients who are undergoing elective surgery. There has been no objective placebo-control trial conducted to support their use.

In addition, subjection symptoms of dry eye may be related to underlying depression resulting from dry eye. Another consideration is that in patients who have undergone gastric bypass surgery, these nutrients will not be absorbed.

Read

ASCRS 2008 meeting highlights.