Age-Related Macular Degeneration & Alzheimer’s

Similar Diseases, Different Locations, Possible Common Treatments

There are many similarities between two age-related diseases (Age-related Macular Degeneration and Alzheimer’s disease) that can affect thousands of people world-wide. In the United States there are 11 million people that have some form of AMD and it is estimated to grow to 22 million by the year 2050. Furthermore, in 2016 it was estimated that the cost to care for those with AMD was $512 billion. Worldwide it is estimated that by 2020, there will be 96 million people with AMD. National Eye Institute 

The second aging disorder that causes high degree of damage is Alzheimer’s disease. Presently, in the United States there are 5.4 million people with Alzheimer’s disease and this will increase to approximately 13.8 million by 2050. In 2016, the cost for caring for these patients was $236 billion. Worldwide the numbers of Alzheimer’s patients are estimated to be 44 million and the global cost is $605 billion. Alzheimer’s Association

Similar Risk Factors

The risk factors for both AMD and Alzheimer’s disease are very similar to each other. These include aging, smoking, and high cholesterol. Both diseases are found more frequently in women than men and in approximately 5% to 15% the diseases are found in more than one family member. There is also a genetic risk factor of a lipid transport protein called Apolipoprotein E (ApoE) that provides elevated risk in AMD patients if they carry the allele 2 variant and higher risk in Alzheimer’s patients if they carry the allele 4 variant.

In AMD and Alzheimer’s disease there are 3 events that make the pathologies very similar except that they are found in different locations, either the retina or the brain.

1. Amyloid beta is a protein that is not present in normal tissues but larger quantities accumulate in the brain for Alzheimer’s patients and are identified to be plaques by MRI scans. The presence of these plaques is defining (pathognomonic) for Alzheimer’s disease. In AMD patients amyloid-beta deposits are found to accumulate underneath the retina and form small clumps of protein-lipid materials called drusen. This is significant because the amyloid-beta is very toxic and harmful to the surrounding cells and when it is accumulating in tissues, it causes the cells to be damaged and loss their abilities to function.

2. A second feature of both AMD and Alzheimer’s disease is that there are high levels of tissue damage, loss of function and a lot of cell death in the retina and brain.

3. Finally, both diseases have damage to the mitochondria, which are small units within the cells that are critical to keeping the cells alive. The mitochondria are the “batteries” of the cell providing energy to keep the retina and brain cells functioning. Mitochondria are similar to the batteries in a flashlight. You can have a very expensive flashlight but if you do not have good batteries, the flashlight will not work. It is a similar situation to the cell. As long as the mitochondria are healthy and providing energy the cells can function. However, when the mitochondria start to die, then the cells will lose their functions and cell death will occur. This is true for all types of cells in the body, such as nerve cells, muscle cells, retinal cells, heart cells, etc. In other words, healthy mitochondria are critical to keep cell alive and functioning well.

Future Treatments

Using a novel in vitro model called cybrids (cytoplasmic hybrids), Dr. Cristina Kenney’s laboratory has shown that when mitochondria from patients with AMD are placed into specialized human retinal cells, the AMD mitochondria will cause the cells to die more rapidly than normal because they are so damaged. With this important discovery, the goal of the research group has been to identify drugs and proteins/peptides that can rescue the damage AMD mitochondria and protect the retinal cells. Their research is moving forward very quickly and testing drugs is the top priority for Dr. Kenney’s group. By rejuvenating the mitochondria from ‘old-damage’ to ‘new-healthy’ will prolong the health of the retinal cells and protect vision loss from AMD. What is learned in these studies will have long reaching applications to other aging-diseases such as Alzheimer’s and Parkinson’s diseases.

Your Vision is Your Wealth

We see more than 24 million images in our average life span. The huge task in a human body is seeing, which requires half of one’s brain to function. Our eye lenses are equal to 576 megapixels Camera lens.

One man out of every twelve men is color blind and the chances of losing eye function increase with age. In the UK 74% of people correct their eyesight by Laser Surgery, Wearing Contact lens and glasses to have a better view. Our eyes take only 48 hrs to repair from a corneal scratch. In order to avoid these problems, restrict the continuous usage of contact lens less than 19 hours in a day.

For a better understanding, read this infographic from Paul Gill Optician.

Things-you-did-not-know-about-your-Eyes_22.11.2016

Source and Author:
Amy Lynn
Paul Gill Optician

AMD and a Healthy Diet: How they Relate

While there is still no concrete answer as to why some do not develop age-related macular degeneration (AMD) and other’s do, significant studies have proven the importance of a healthy diet and the mitochondria.

AMD is the leading cause of vision loss for those over 60 years of age in the developing countries. For decades we have studies that show the genetics and environmental factors associated with AMD. There have been over 20 genetics modification associated with AMD but there is no single gene that “causes AMD in all cases.” The genes most highly associated with AMD are found in the complement system, an important system related to controlling the inflammation in our body. A change in the complement factor H (CFH) gene from a low risk gene to a high risk gene has been associated with 43% of those developing AMD.

However, some people who have this high risk CFH gene but never develop AMD. This leads us to believe that the genetics are not the entire answer. The other factor has to do with the environment. Smoking is the leading risk factor, along with aging, exposure to sunlight and higher body mass index (obesity). But again there are obese people that smoke and never develop AMD. So, while the environmental risk factors are important, they do not answer the entire question of “why do some people get AMD but others do not?”

Recently, researchers have recognized that a major factor in the dry form of AMD is that the retinal cells begin to die off. Therefore, they have looked at important factors that keep cells alive. The mitochondria are one of the most important elements that protect the cells in the body. These subunits or organelles, produce energy for the cells, acting like batteries for the cells. And just like the batteries in a flashlight – if the batteries are not working then the flashlight dies. The same thing happens with cells – when the mitochondria are not healthy, then the cells eventually will die. Therefore to protect ourselves, it is important to keep the mitochondria healthy. One way to do this is to eat healthy foods. Over the past 20 years, the National Eye Institute (NEI) has conducted a series of studies that have identified foods and supplements that are good for the retinal cells and also the mitochondria.

 

super greens, spinachThe National Eye Institute has recommended that people who are high-risk for developing AMD eat diets rich in green leafy vegetables, whole fruits, any type of nuts and omega 3 fatty acids. Many of these foods have anti-oxidant properties that help to “turn off” genes involved with inflammation, an important factor of retinal diseases. Salmon, mackerel and sardines have the highest levels of omega-3 fatty acids. An analysis that combined the data from 9 different studies showed that fish intake at least twice a week was associated with reduced risk of early and late AMD. Other studies show that Omega-3 fatty acids improve mitochondrial function, decreases production of reactive oxygen species (free radicals that damage cells) and leads to less fat accumulation in the body. The green leafy vegetables contain important protective macular pigments (carotenoids) called lutein and zeaxanthin that reduce the risk of AMD by 43%. High levels of lipid or fat deposits in the body (obesity) can “soak-up” the lutein and zeaxanthin so that they are not available to protect the retina.

The goal is to increase the omega-3 fatty acid and carotenoid levels to protect the eye. Below is a list of foods that are eye healthy:

Foods that have lutein or zeaxanthin:

– 6mg/d of lutein and zeaxanthin – decreased

– Lutein/zeaxanthin content – ug/100g wet weight

– Kale, cooked – 15,798

– Spinach, raw – 11,935

– Spinach, cooked – 7,053

– Lettuce, raw – 2,635

– Broccoli, cooked – 2,226

– Green peas, cooked – 1350

Source: Johnson, et al 2005 Nutr Rev 63:9

 

To help kickstart an eye healthy diet, here is a list of “eye-healthy recipes” that provide nutritional support for the mitochondria and retinal cells.

Asparagus Soup
Kale Chips
Quinoa Collard Green Wraps with Summer Vegetables
Smoked Salmon Rillettes

Sources:
Geoffrey K. Broadhead, John R. Grigg, Andrew A. Chang, and Peter McCluskey Nutrition Reviews. Dietary modification and supplementation for the treatment of age-related macular degeneration VR Vol. 73(7):448–462

Chong et al., Dietary omega-3 fatty acid and fish intake in the primary prevention of age-related macular degeneration: a systematic review and meta-analysis. Arch Ophthalmol 2008;126:826–33.

5/19/16

courtesy of the
SFCulinaryAcademyLogoWEB

 

 

Drugs to Treat Dry AMD and Inflammation

12/2/14

Below is an article from the monthly Macular Degeneration Partnership E-Update on potential drugs to treat dry AMD and inflamation. To learn more about dry AMD, including stem cell treatments, go to AMD.org. You can also subscribe and have the monthly newsletter delivered to your inbox.clinical trials for drugs to treat dry age-related macular degeneration

There are many causes of age-related macular degeneration and any of them may prove a good target for treatment for dry AMD. A long list of these was discussed at the recent Academy of Ophthalmology meeting. They were divided into the types of drugs being studied. We’ll look first at inflammation and the complement factor system, which is part of the immune system.

Inflammation is known to be associated with macular degeneration. The target may be the inflammation itself, or the cause of the inflammation.

Lampalizumab (or anti-Factor D) is a drug that is injected into the eye. In earlier Phase II trials, it was shown to reduce the area of the geographic atrophy by 20%. A Phase III clinical trial is now underway for individuals with geographic atrophy from dry AMD. Several research sites are actively recruiting now and many others will start recruiting in the near future. For more information and a list of participating centers, visit Clinical Trials.

LFG316 is also an antibody and an injection. This Phase 2 study is a randomized clinical trial of a drug that targets the C5 complement pathway (part of our immune system). It is designed to test the safety and efficacy of different doses of LFG316. There are three arms in the study: one group receiving a higher dose of the drug; one group receiving a lower dose of the drug; one group receiving a sham injection (no drug). These are successive monthly injections for people with geographic atrophy (GA). It is taking place in multiple locations throughout the U.S. and is sponsored by Novartis. For more information and a list of participating centers, visit Clinical Trials.

Oracea is a pill for dry macular degeneration, now in Phase II/III clinical trials around the U.S.. The pill contains doxycyline, which suppresses inflammation. Participants will be randomly assigned to either receive the drug or a placebo. More information at Clinical Trials.

Zimura by Ophthotech has been tested as a drug for wet AMD, but also seems to affect the drusen of dry AMD. Zimura targets the complement pathway plays a significant role in dry AMD. A Phase 2/3 clinical trial investigating ZimuraTM for treatment of geographic atrophy, is in the planning stages.

Eculizumab was also presented. This intravenous treatment for dry AMD did not show the desired effect in clinical trial, so no further development is planned at this time.

POT-4 is another drug that targets the complement factor system involved in inflammation. It is delivered through injection into the eye. The Phase I trial is completed and a Phase II clinical will be announced soon.

Iluvien is a drug delivery system that has been used in patients with diabetic retinopathy. A Phase II clinical trial for dry AMD is underway, though it is no longer recruiting patients. This is an implant inside the eye that releases fluocinolone acetonide. For more information, see Clinical Trials.

Judi Delgado - age-related macular degenerationJudith Delgado
Executive Director
Macular Degeneration Partnership
A Program of the Discovery Eye Foundation