Eyeworld

EW CORNEA 28 January 2018 by Maxine Lipner EyeWorld Senior Contributing Writer Beyond prescription medications Natural therapies for meibomian gland disease F or patients with meibomian gland disease today, prac- titioners often reach for nat- ural remedies, which would have been unheard of in the past, according to Edward Holland, MD, professor of ophthalmology, University of Cincinnati. "Five years ago, it was pretty uncommon," he said. "I think there has been a lot of clinical evidence on the value of omega-3 and the importance of nutrition in treating dry eyes, and I think many clinicians are now aware of it." In addition, patients are now often asking for practi- tioners' opinions on this. Omega-3 supplements have become one of the main remedies practitioners are pointing patients to. "Unfortunately, our diet is filled with the wrong fatty acid," Dr. Holland said. Patients tend to ingest too many omega-6 fatty acids, while there isn't enough omega-3 in the diet. People can obtain omega-3 mian glands is to produce a healthy mixture of lipids to preserve the ocular tear film through preven- tion of evaporation. "The organic health of those secretions depends on nutritional intake of the correct essential fatty acids," Dr. Sheppard said. He stressed that the effect of the fatty acids is anti-inflammatory throughout the body. In addition, the awareness that a pill bought over the counter can be as effective as expensive prescription medica- tion hits home for many, he finds. The evidence The evidence for using omega-3 fatty acids is growing. Dr. Shep- pard cited two landmark studies. One published by his group looked prospectively at the use of a com- bination of polyunsaturated fatty acids that showed a significant im- provement in several parameters in patients after 6 months. 1 "Our study showed that patients had stabiliza- tion rather than worsening of two ocular surface inflammatory markers seen in the placebo control group," Dr. Sheppard said, adding that it also showed an improvement in the Ocular Surface Disease Index as well as some of the irregular astigmatism markers from corneal topography. "A subsequent multicenter, placebo-controlled, masked, pro- spective, randomized study was published looking at re-esterified omega-3 essential fatty acids," Dr. Sheppard said. "This trial showed that those concentrated supple- ments, assumedly through their improved bioavailability, improved a wide variety of parameters in pa- tients with dry eye." 2 Still, as Dr. Downie pointed out, there is no consensus yet. "As sum- marized in the recently published Tear Film & Ocular Surface Society Dry Eye Workshop II (DEWS II) Management and Therapy Report, 3 the role of omega-3 and/or omega-6 supplementation for treating dry eye disease and meibomian gland disease is not yet completely un- derstood," Dr. Downie said, adding that although a sizable number of studies have been conducted, some have been relatively short and there have been a number of contrasting findings. What's more, there are few high quality randomized trials to help practitioners determine what an optimal protocol may be. Pharmaceutical focus Chronic meibomian gland dysfunction with thickened opaque meibum Source: Edward Holland, MD from raw nuts and fish. "But most experts don't recommend eating fish 7 days a week because of the poten- tial toxins," Dr. Holland said. "So the only real way to ingest signifi- cant omega-3 is with supplements." Why omega-3 works Laura Downie, PhD, senior lec- turer, University of Melbourne, Australia, explained that it has been well established that inflammation plays a key role in the pathogene- sis of dry eye disease. "The major mechanism through which omega-3 supplements are considered to be therapeutic in dry eye is through modulating the inflammatory status of the eye by altering systemic cyto- kine production," Dr. Downie said. While both omega-6 and omega-3 fatty acids are needed in a healthy diet, people commonly get too much omega-6. "The ratio of consumed omega-6 to omega-3 is a determinant of the overall inflam- matory status of the body," she said. "While the omega-6 pathway mostly produces pro-inflammatory mediators, the omega-3 pathway biases prostaglandin production toward the generation of anti-in- flammatory mediators." In modern Western diets, the ratio of consumed omega-6 to omega-3 is typically 15 to 1, whereas an ideal ratio is about 4 to 1. "By increasing systemic ome- ga-3 EFA levels with dietary supple- ments, we can lower the omega-6 to omega-3 ratio, with the intent of yielding anti-inflammatory bene- fits," Dr. Downie said. Omega-3 supplements may also directly alter meibomian gland lipid secretions. "It has been shown that the level of omega-3 intake is asso- ciated with differences in the polar lipid pattern of meibomian gland secretions in women with Sjögren's syndrome," Dr. Downie said. "In addition, supplementation with short-chain omega-3 can alter the composition of meibomian gland secretions, with corresponding im- provements in gland blockage and tear stability." John Sheppard, MD, president, Virginia Eye Consultants, Norfolk, Virginia, pointed out that the underlying function of the meibo-

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