Category: Eye Conditions

Risk Of Stroke Greater For Those With Glaucoma

Open angle glaucoma has been identified as a risk factor for stroke, but recently researchers have tightened this connection.  They analyzed information from the over 1 million patients identified in the Taiwan National Health Insurance database, comparing over 4000 patients with OAG to over 20,000 patients without the condition – the data came from a 5 year period.

Almost 15% of the patients identified as having OAG had strokes within the 5 years; only 9.5% of the non-OAG patients had strokes in the 5 year period.

The researchers adjusted the data for demographics and found that OAG patients were 1 1/2 times as likely to suffer a stroke within that time span.

A later study by Dustin French, PhD substantiated this information.

 

Learn more about glaucoma including self-help tips

Read other studies about glaucoma

SOURCE:  “Open-Angle Glaucoma and the Risk of Stroke Development. A 5-Year Population-Based Follow-Up Study”, Ho, et al, PubMed, 2009 May 21, https://www.ncbi.nlm.nih.gov/pubmed/19461039

Researchers: Jau-Der Ho and associates, Taipei Medical University in Taipei, Taiwan

 

AMD Linked to Cognitive Decline

Seniors who experience cognitive decline and don’t do well on memory, language, and concentration tests are more likely to be suffering from the early developing macular degeneration. Researchers found that patients with impaired memory are more likely to have AMD without regard to their age, their education, and vascular risk factors that are commonly tied to cognitive difficulties.

The researchers evaluated over 2000 patients from 69 to 97 years old, who were part of a heart health study.  Their cognitive functioning was assessed and they were also evaluated for dementia with neuropsychological testing methods.

After controlling for age, gender, race, and location, the researchers found that patients with poor cognitive functioning were more likely to have early AMD than were patients with higher assessments.  Analysis additionally controlled for blood pressure, cholesterol level, diabetes, education and whether and how much the patients smoked, as well as whether the patients had a particular apolipoprotein E genotype, and found the connection to be even greater.  However the researchers did not find a tie of dementia or Alzheimers’ with AMD development.

 

Researchers: Dr. Tien Yin Wong, and associates, Department of Ophthalmology, Centre for Eye Research Australia, University of Melbourne, Australia.

Published:  Early Age-Related Macular Degeneration, Cognitive Function, and Dementia – The Cardiovascular Health Study, Baker, et al, Arch Ophthalmol. 2009;127(5):667-673.

 

Macular Degeneration: Techniques for Adaption

Refocusing Vision | Cortical Reorganization

Refocusing Vision

Patient who develop age-related macular degeneration lose their central vision but their peripheral vision often is not damaged  The UK Macular Disease Society has developed a method to train people to use the undamaged parts of their eyes to read and identify faces. 

Patients can be taught to use their peripheral vision to make up for damage to their central vision, using “eccentric viewing” and “steady eye techniques” which means that by not looking directly at an object, but above, below, or to one side, they can see it more clearly.

The training process teaches patients  where to focus their gaze to improve their vision. The method works, not only for general vision but for reading as well – by moving the text rather than the eyes so that the words move into the portion of the gazed where the patient has good vision.

Learn more about macular degeneration

SOURCE:  BBC News Channel, April 10, 2009, https://news.bbc.co.uk/1/hi/health/7958838.stm

Cortical Reorganization

Not only can people be taught techniques for adapting to loss of central vision, but apparently the brain also begins to adapt.

A new study shows that when people with retinal disease such as macular degeneration use a peripheral part of their retina to compensate for their loss of central vision, their brain appears to compensate by reorganizing its neural connections – a cortical reorganization.

Researchers  used functional magnetic resonance imaging (fMRI) to measure brain activity of patients performing tests that stimulate the peripheral areas of vision.  They found that when patients did so brain activity was more active in the parts of the brain where activity is seen when central vision is employed.

The researchers feel  that large-scale cortical reorganization of visual processing occurs in humans in who experience retinal disease.  While several other studies have suggested that the brain can reorganize itself, this is the first study to show that this reorganization in patients with retinal disease is related to patient behavior.

Researchers are currently analyzing how long this reorganization takes and whether it can be assisted with low-vision training.

Researchers: Georgia Institute of Technology

Published: Reorganization of visual processing is related to eccentric viewing in patients with macular degeneration, Schumacher, et al, Restorative Neurology and Neuroscience, Volume 26, Number 4-5, 2008, 391 – 402.

Link Discovered Between Glaucoma and WDR36 Gene

In glaucoma, cells in the optic nerve die, preventing the brain from understanding what patients see, first in peripheral vision and gradually in all vision.  It is associated with high levels of intraocular pressure and connected to risk factors to and from a number of other conditions including stroke, herpes virus, hypothyroid conditions, and many lifestyle factors.

Researchers have thought for some time that there may be a tie between the WDR36 gene and glaucoma.  However, they’ve not been able to understand exactly why that gene has an effect and why some patients with that gene mutated or varied have glaucoma but other patients do not.

A new study indicates that glaucoma develops as a result of changes in several different genes, not only WDR36.   This explains the mixed results. The researchers found that 10% of glaucoma incidents arise due to genes that have been understood – the idea of simultaneous changes in several different genes explains much.

The function of the WDR36 gene is to help make specific molecules known as ribosomes that are instrumental in creating proteins to help optic nerve cells function properly.  If WDR36 changes and does not help produce ribosome, the entire process falters.  Another gene that is critical to the process is STI1 which adapts the ribosome-created proteins to a form that the cell can utilize.  So if WDR36 doesn’t produce ribosomes properly AND STI1 doesn’t “package” properly – the 2 mutations synergistically cause glaucoma.

Learn more about glaucoma

Researcher: Dr. Michael Walter and associates, University of Alberta, Department of Medical Genetics in the Faculty of Medicine & Dentistry

Published:  “Genetic Sleuth Solves Glaucoma Mystery”, University of Alberta Express News, March 20, 2009

 

 

Vitamin B and Folic Acid May Lower Risk of AMD

B & Folic Acid | B6, B12 & Folic Acid | Homocysteine

Vitamin B & Folic Acid

A team of Harvard researchers found that women who took a combination of folic acid and vitamins B6 and B12 had a 35% to 40% lower risk of developing age related macular degeneration (AMD) than women who took a placebo.

A group of 5442 female health care professionals 40 years or older (of whom 5205 did not have a diagnosis of AMD at the beginning of the study) received either a combination of folic acid/B6/B12 or a placebo.

After more than seven years of treatment and follow-up, 137 women were diagnosed with AMD.  Of these 137:

  • 55 had been taking the supplements; 82 had been taking the placebo.
  • 70 had ‘visually significant AMD’, including 26 who had been taking the supplements and 44 who had been taking the placebo.

Researchers concluded that daily supplementation with folic acid, pyridoxine (vitamin B6), and cyanocobalamin (vitamin B12) may reduce the risk of AMD.

Published:  “Folic Acid, Pyridoxine, and Cyanocobalamin Combination Treatment and Age-Related Macular Degeneration in Women”, Christen et al, Arch Intern Med. 2009;169(4):335-341.

Folic Acid, Vitamins B6 & B12

Researchers reviewed data from the “Women’s Antioxidant and Folic Acid Cardiovascular Study,” looking specifically at vision information. They found that supplementation with a combination of folic acid, vitamin B6 and vitamin B12 lowered the risk of age related macular degeneration in women who also have cardiovascular disease.

Scientists have known that these 3 B family vitamins reduce high homocysteine levels, a risk factor for conditions of the vascular system, including advanced macular degeneration.

The study looked at data for over 8,000 age 40 or older female medical professionals  who had been diagnosed with cardiovascular disease or who had a minimum of 3 risk factors for development of macular degeneration.  In a secondary trial they randomly received vitamin C daily, vitamin E every other day, and beta-carotene (every other day) or a placebo.

About 5,400 of these women were part of a later trial in which they received a placebo or a combination of folic acid, vitamins B6 and B12 or a placebo daily.  About 200 of these women had previously been diagnosed with macular degeneration.  Results were both self-reported, confirmed by medical records, and diagnosed as macular degeneration with vision reduced to 20/30 or lower due to the condition.

The researchers determined that 137 macular degeneration cases occurred over approximately 7 years of treatment and followup. There were 55 incidences in the group receiving treatment and 82 occurences in the placebo group.  The results for patients with macular degeneration and 20/30 or worse vision loss, there were 26 incidences in the B vitamins sub-group, and 43 cases in the placebo sub-group.

The researchers determined that women who take supplement B vitamins are 34 percent less likely to experience macular degeneration, and 40 percent less likely to experience vision loss as a result.

The researchers noted that although high doses of  B vitamins were tested, lower doses may well have been effective.  Another study looking at cardiovascular disease found that homocysteine decrease if proportional to the dose of folic acid only up to 800 mcg daily while excessive amounts of folic acid have been tied to colorectal tumors.

Researchers: Brigham and Women’s Hospital and the National Eye Institute

References :
Christen WG, et al. Folic acid plus B-vitamins and age-related macular degeneration in a randomized trial in women. Investigative Ophthalmology & Visual Science 48:E-abstract 1152, ARVO, 2007.
Wald DS, et al. Randomized trial of folic acid supplementation and serum homocysteine levels. Archives of Internal Medicine 161:695-700, 2001.

Homocysteine

Homocysteine, an amino acid believed to contribute to heart attack, stroke and dementia, may also play a role in retinal damage and vision loss.  Homocysteine levels rise when folic acid levels drop, a common problem for Americans whose diets are often poor in folate-rich fruits, tomatoes, vegetables and grains.

Researchers are looking at homocysteine levels upon the retina to find out exactly what happens in this vast and delicate network.  Looking at retina photos, one can see that the structure of the retina is damaged significantly in patients with high levels of homocysteine.

Folic acid and vitamin B12 convert homocysteine to methionine, an amino acid essential to protein synthesis.  People need only about 1 mcg  of vitamin B12 daily.  The source of B12 is microorganisms that are common in the gastrointestinal system of animals. Strict vegetarians are typically the only Americans who have problems with B12 deficiency, he says. People need about 400 micrograms of folic acid daily. Pregnant women as well as those trying to become pregnant need at least double that.

Researchers are investigating several mice models and will control their diets to raise and lower folic acid levels to see what happens to homocysteine and the retina:

  • a model  with slightly raised homocysteine levels that behave like a human diet deficient in folic acid –  this model that also has diabetes, which goes along with cardiovascular disease and diabetic retinopathy;
  • a model of the rare genetic defect that results in extraordinarily high homocysteine levels.

The scientists believe that continual raised homocysteine levels will damage the normal functioning of the retina and degrade the retinal tissue, a situation that is worsened by diabetes.

Researchers: Dr. Sylvia Smith, cell biologist, and Dr. Vadivel Ganapathy, Chair, Department of Biochemistry and Molecular Biology, Medical College of Georgia

Published:  Medical College of Georgia, “Impact of elevated homocysteine levels on vision under study,” Oct. 15, 2007.

B & Folic Acid | B6, B12 & Folic Acid | Homocysteine

 

Obesity Increases Risk of Macular Degeneration

AMD associated with higher Body Mass Index, Waist Circumference, and Waist-Hip Ratio

People with early or intermediate stages of age-related macular degeneration (AMD) make up a large and growing segment the elderly population.

Researchers interested in identifying preventative measures to help this group lessen their risk of advanced AMD conducted a survey of 261 participants from a hospital-based retinal practice.  Participants were aged 60 years or older, with some sign of nonadvanced AMD and visual acuity of 20/200 or better in at least 1 eye.

The results of the study showed that obesity (measured in body mass index) greatly increases the risk for progression to the advanced forms of AMD. 

In addition:

  • Higher waist circumference was associated with a 2-fold increased risk for progression, with a significant trend for increasing risk with a greater waist circumference
  • Higher waist-hip ratio also increased the risk for progression
  • More physical activity tended to be associated with a reduced rate of progression (25% reduction for 3 times per week vigorous activity compared with no activity)

Study authors believe that the results provide new information regarding modifiable factors for individuals with the early or intermediate stages of this disease.  Although overall and abdominal obesity increased the risk for progression to advanced AMD, increasing physical activity tended to decrease risk.

Learn other natural preventative measures to lesson your risk of AMD

SOURCE:  Progression of Age-Related Macular Degeneration, Seddon, et al, Arch Ophthalmol. 2003;121:785-792

Cataract Surgery Does Not Increase Risk of AMD

Cataracts and age-related macular degeneration (AMD) are both leading causes of blindness in the United States, but scientists have been uncertain if the two diseases may be linked. Researchers have just completed a study to assess the risk of developing AMD after cataract surgery.

4,477 participants in the Age-Related Eye Disease Study (AREDS), a multicenter, controlled, randomized clinical trial were assessed every six months for at least five years.

Emily Y. Chew, MD, of the National Eye Institute and her colleagues evaluated the data and compared the risk of AMD in participants who had cataracts removed with those who have not had the surgery.

Their conclusions? The AREDS results showed no clear effect of cataract surgery on the risk of progression to advanced AMD, which may reassure patients with AMD who are considering cataract surgery.

Learn more about natural care and treatment of AMD and cataracts

SOURCE: Risk of Advanced Age-Related Macular Degeneration after Cataract Surgery in the Age-Related Eye Disease Study: AREDS Report 25, Chew et al, Ophthalmology – February 2009 (Vol. 116, Issue 2, Pages 297-303.

Vitamins E and B May Slow Lens Opacity

Long-term use of vitamin E supplements, as well as increased intake of riboflavin (vitamin B2) and/or thiamin (vitamin B1), may help reduce the progression of age-related lens opacification.

Lens opacification (or clouding) is caused by the disruption of the transmission of light through the eye lens due to damage to the lens cells.  When the opacification creates a reduction in visual acuity, it is referred to as a cataract.   Studies suggest that oxidation is responsible for much of the damage to the lens and that antioxidants, such as vitamins C and E, might protect the lens against formation of cataract.

Researchers conducted a five-year study of 408 women from the Nurses’ Health Study, aged 52 to 74 years at baseline. The women’s nutrient intake was calculated from five food frequency questionnaires collected over a 13- to 15-year period.  During this time the duration of vitamin supplement use was assessed using seven questionnaires.  At the end of this period the degree of nuclear density was determined.

Women who never supplemented with vitamin E had a 42% higher risk of getting cataracts than women who had supplemented vitamin E for 10 years.

Researchers concluded that long-term use of vitamin E supplements and higher riboflavin and/or thiamin intake may reduce the progression of age-related lens opacification.

Where can you find good sources of these vitamins?

  • Vitamin E can be found in almonds, asparagus, avocado, nuts, olives, red palm oil, seeds, spinach and other leafy vegetables, wheat germ, and milk
  • Riboflavin is found naturally in asparagus, bananas, okra, chard, cottage cheese, milk, yogurt, meat, eggs and fish.
  • Foods rich in thiamin include yeast, oatmeal, brown rice, whole grain flour (rye or wheat), asparagus, kale, cauliflower, potatoes, oranges, liver (beef or pork), and eggs.

Learn more about cataracts including recommended vitamins and supplements

Source:  Jacques, et al, Long-term Nutrient Intake and 5-Year Change in Nuclear Lens Opacities, Arch Ophthalmol. 2005;123:517-526.

Meso-Zeaxanthin Aids Eyes

Lutein and zeaxanthin have been well researched as being essential nutrients in both helping to prevent the onset of macular degeneration as well as helping protect vision for those with macular degeneration. People with macular degeneration have been shown to have reduced macular pigment optical density (MPOD).

Meso-zeaxanthin is the third major carotenoid found in macular pigment (along with lutein and zeaxanthin).

A new study showed that supplementation of gelcaps containing mostly mesozeaxanthin (along with some lutein and zeaxanthin) resulted in increased blood serum levels of all three carotenoids during the 120 day study supplementation period, and was effective in increasing macular pigment optical density (MPOD).

Ref: Florida International University (Nutr Metab. 2007;4:12)

Another study substantiates the value of supplementing with mesozeaxanthin.

Nutrition & Metabolism 2007, 4:12

See more information on macular degeneration and mesozeaxanthin.

Antioxidant-Rich Diet May Protect Against Eye Disease

FRIDAY, Aug. 29 (HealthDay News) — Eating plenty of antioxidant-rich food such as blueberries, artichokes and pecans may help protect against macular degeneration, the leading cause of age-related blindness in the United States and other developed countries.

U.S. researchers found that antioxidants disrupt a link between two processes in the retina that, in combination, contribute to macular degeneration. Antioxidants also extend the lifetime of irreplaceable photoreceptors and other retinal cells.

The “destructive synergy” that causes macular degeneration occurs when a buildup of a compound called A2E disrupts energy production in mitochondria, the “power plants” in cells, the researchers said. The lack of energy interferes with daily cleaning and maintenance of photoreceptors and another type of retinal cell. This leads to more buildup of A2E and a continuing cycle that results in the destruction of the vital visual cells that can’t be replaced.

Experiments using visual cells from humans, rats and cows showed that antioxidants could completely counter the damage caused by this process, said the researchers from Brigham Young University and Weill Medical College of Cornell University.

“The implication is that people at risk of macular degeneration could help prevent the disease by consuming antioxidants,” study author Heidi Vollmer-Snarr, a Brigham Young chemist, said in a university news release.

The study was published online in the Journal of Biological Chemistry.

“This work by Dr. Vollmer-Snarr and colleagues ties these two damaging processes together and demonstrates the harm they cause in combination is much more than would be expected,” Dr. Paul Bernstein, of the University of Utah’s Moran Eye Center, said in the news release. “This new knowledge,” added Bernstein, who wasn’t involved in the study, “suggests the possibility of interventions which could prove to be powerful ways to prevent or delay age-related macular degeneration.”

For more related studies, go to the “Research” section as www.naturaleyecare.com