Oct 22, 2015

Harnessing Omega-3 Fatty Acids to Fight AMD

We need better treatments for age related macular degeneration (AMD). Currently AMD is the leading cause of blindness in the Western world and studies predict that the number of patients will double over the next 15 years, as the baby boomer population ages.

While the treatment of AMD was revolutionized by the advent of anti-VEGF therapy, there is certainly room for improvement. Anti-VEGF drugs such as Lucentis and Avastin are now used so commonly to treat retinal diseases that ophthalmologists refer to them as the “parmesan cheese” of eye disease; just sprinkle a little on everything, because it generally seems to help. The cost of these drugs, however, is very high, and they also may bring long-term risks. This is because VEGF plays an important role in maintaining the health of blood vessels throughout the body and there is increasing evidence that even though anti-VEGF drugs are injected directly into the eye, they have the potential to cause harm over the long term.

This is why Dr. Przemyslaw (Mike) Sapieha is determined to find a safer and more cost-effective treatment that does not require repeated, technically difficult and expensive injections of drugs into the eye.

Researchers around the world are experimenting with different strategies to combat AMD. One approach involves attempting to change the make-up of the retina’s cell membranes; this is the approach that Dr. Sapieha’s team is using. What does it involve? The outer retina (where the rod and cone photoreceptors are located) is rich in fatty acids of the omega-3 family, such as docosahexaenoic acid (DHA). Although we are accustomed to thinking about lipids/fats as nothing more than a place where energy is stored—and that make us too big where we don’t want to be—they also play important biological roles. Failures in some of these roles can cause a variety of diseases, including AMD. We have to get omega-3s in certain foods that we eat, such as salmon and flax seeds, because our bodies don’t make enough of them. Many studies of wet AMD have emphasized the benefits of taking omega-3s as a supplement. But these studies remain somewhat inconclusive, leaving patients wondering about the best course of action.

In 2013, Fighting Blindness Canada began funding Dr. Sapieha’s AMD research, which focuses on the effects of omega-3 fatty acids on abnormal blood vessel growth in wet AMD. With Dr. Flavio A Rezende, vitreoretinal surgeon at Hoptial Maisonneuve-Rosemont, his team set out to evaluate the effects of omega-3 supplements in patients with wet AMD, who were also receiving anti-VEGF injections into the eye. To test the effects, the team conducted a pilot study (randomized clinical trial) to test the effectiveness of omega-3 supplements in patients having wet AMD, compared to that in a control group. Their exciting results showed that the patients who received omega-3s had significantly lower levels of VEGF-A in the vitreous humour than did those in the control group. This is what they were hoping to find because lower levels of VEGF signify lower risk of wet AMD (this is exactly what anti-VEGF drugs strive to accomplish). By understanding this effect, his team aims ultimately to develop new forms of omega-3 compounds for treating wet AMD.

These important, clinically relevant findings will be published the November issue of the American Journal of Ophthalmology (and the results are currently available online). Since their paper appeared online, it has become the most highly-read paper by US physician subscribers, according to MDLinx Ophthalmology! This shows that their research has the potential to have a significant clinical impact.

About the Study:

The paper appears in the November 2014 issue of the American Journal of Ophthalmology with the title: “Omega-3 Supplementation Combined With Anti–Vascular Endothelial Growth Factor Lowers Vitreal Levels of Vascular Endothelial Growth Factor in Wet Age-Related Macular Degeneration.” The authors include Flavio A. Rezende, Eric Lapalme, Cynthia x. Qian, and Przemyslaw Sapieha, who are all affiliated with the Department of Ophthalmology, Maisonneuve-Rosemont Hospital Research Centre, University of Montreal; Lois Smith, who is affiliated with the Department of Ophthalmology, Children’s Hospital Boston, Harvard Medical School, Boston, Massachusetts, and John Paul Sangiovanni, who is affiliated with the Clinical Trials Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland.