Dry Eye Syndrome and Omega-3 Fatty Acid
Rahul Bhargava, MD
B2/004, Ananda Apartments
Sector-48, Noida 201301, India
+911204215085
brahul_2371@yahoo.co.in
“A Randomized Controlled Trial of Omega-3 Fatty Acids in Dry Eye Syndrome,” Int J Opthalmol, 2013 Dec 18;6(6):811-6. 49814 (3/2014)

Kirk Hamilton: Can you share with us your educational background and current position?

Rahul Bhargava: I have a MD in Ophthalmology and Fellowship from the L.V. Prasad Eye Institute, Hyderabad India. I am Professor of Ophthalmology at Santosh Medical College, Ghaziabad, India.

KH: What got you interested in studying the role of omega-3 fatty acids (O3FA) and dry eye syndrome (DES)?

RB: Dryness of eyes is a very common problem in the subcontinent. Diagnosis of dry eye is challenging due to poor standardization of routine tear function tests. Secondly, most currently used medications provide temporary and symptomatic relief. Omega-3 fatty acids have shown promising results in ARMD and elsewhere.

KH: What is the biochemistry of O3FA that might alter the pathophysiology of DES?

RB: Our current knowledge of DES has suggested that inflammation of the ocular surface is an integral component of meibomian gland disease and aqueous deficient dry eye. The ratio of omega-6 to omega-3 fatty acids influences inflammatory cytokines in the body. Increased production of anti-inflammatory PGE1 and PGE3 that occur with an increase in omega-3 levels may alter the pathophysiology of dry eye. Secondly, accumulating evidence suggests that dietary supplementation induces changes in the fatty acid saturation content in meibum.

KH: When you talk about O3FA are you really talking about EPA and DHA and not alpha-linolenic acid (ALA) from plant food?

RB: ALA is found in flaxseeds, flaxseed oil, canola (rapeseed) oil, soybean oil, pumpkin seed oil, purslane, perilla seed oil, walnuts, and walnut oil. The health effects of omega-3 fatty acids come mostly from EPA and DHA. ALA from flax and other vegetarian sources needs to be converted in the body to EPA and DHA.

KH: Where did you come up with a daily dose of 650 mg EPA and 350 mg DHA? How was it taken? With meals or away from meals? In a single dose or divided dose?

RB: This combination is marketed in India. One capsule was prescribed twice daily with meals. One capsule = EPA 325 mg and DHA 175 mg.

KH: Were blood levels of EPA, DHA or other biochemical markers taken before, during or after the intervention? If so did they correlate with symptoms and supplementation with O3FA?

RB: I agree that alteration of omega-6 to omega-3 ratio in plasma and in RBC membranes is necessary to document that improvement in symptoms score is attributable to dietary supplementation. However, research methodology in subcontinent countries has a number of limitations and financial constraints. We do not have the facility to monitor these levels in our setup. Patient affordability was yet another issue.

KH: Can you tell us about your study and the basic results?

RB: This is probably the first study in which conjunctival impression cytology was used to monitor response to intervention. Patient’s symptoms scores was monitored by our own scoring system (not the OSDI), which can be used by other researchers. A remarkable observation was that dietary supplementation significantly improved tear film stability. However, in contrast to other studies, despite a slight increase in the average, tear production was not altered significantly.

KH: Were there any side effects with the O3FA therapy? How was the patient compliance?

RB: Some patients had gastric discomfort and skin rashes. These were not severe enough to warrant discontinuation of treatment. Platelet count, prothrombin time and activated partial thromboplastin time (APTT) were monitored. None of the patients had an episode of bleeding.

KH: Who is the candidate for EPA/DHA therapy? All subjects of DES?

RB: The results of the present study suggest that the benefit seems to be less marked in patients with aqueous tear deficiency as compared to the evaporative dry eye.

KH: Have there been any studies with plant sources of O3FA such as from flaxseed or chia seeds (ALA)? If so have they shown any benefit?

RB: Some studies have demonstrated that therapy with oral flaxseed oil capsules 1 or 2 g/day reduces ocular surface inflammation and ameliorates the symptoms of keratoconjunctivitis sicca in Sjögren’s syndrome patients (Pinheiro MN Jr, dos Santos PM, dos Santos RC, Barros Jde N, Passos LF, Cardoso Neto J. (Oral flaxseed oil (Linum usitatissimum) in the treatment for dry-eye Sjögren’s syndrome patients. Arq Bras Oftalmol. 2007 Jul-Aug; 70(4):649-55).

KH: Is part of the problem with DES the increased intake of omega-6 fatty acids from animal fat and vegetable oils with the incorporation of the industrialized diet which increases the need for O3FA?

RB: The typical western diet is high in omega 6 FAs, with an average omega 6 to omega 3 FAs intake ratio between 15:1 and 18:1. On the other hand, Mediterranean diet, rich in cold water fish has a ratio of approx. 4:1. This ratio may be somewhere between the two extremes in subcontinent diets. However, there is no evidence that diets with an increased ratio of omega 6 to omega 3 FAs have higher incidence of DES.

KH: Are there any other lifestyle factors or dietary factors that increase the risk to DES?

RB: Malnutrition, protein and vitamin-A deficiencies may compromise tear film health and supplementation with oral vitamin A has shown benefit. A number of population studies have suggested that hyperlipidaemia and a diet low in omega-3 fatty acids are risks factor for dry eye disease. Likewise, researchers found nearly a twofold increase of dry eye in smokers. In addition, past or current users of multivitamins and persons with a history of gout or thyroid disorder, arthritis, fractures, osteoporosis, heavy drinking, and diabetes were all more likely to have the condition.

KH: How can the public or health professionals use this information?

RB: DES has now become an important public health issue impacting both the quality of life as well as the physical health. Public health professionals should bring about a comprehensive, evidence-based educational initiative to increase awareness of chronic dry eye and provide clinicians with state-of-the-art diagnostic and treatment strategies to effectively manage this dynamic disease process. There is no doubt that a prompt diagnosis and effective management of chronic dry eye can improve quality of life of patients.

KH: Do you have any further comments on this very interesting subject?

RB: The study supports the role of inflammation in aetiology of DES. It also demonstrated for the first time that dietary supplementation has a beneficial effect on ocular surface health, as evidenced by improved  impression cytology scores.

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