Macular Degeneration News
Study of Eye Risks From Lifetime UV Exposure Reveals a Surprise
November 2014 Higher-than-average lifetime exposure to ambient ultraviolet radiation (UVR) increases the risk of cataracts and age-related macular degeneration (AMD) but low lifetime UVR exposure might also increase a person's risk of early AMD.
Those are the somewhat surprising results of a new study published this month by Investigative Ophthalmology & Visual Science.
Yes, sunlight is beautiful, but you need to protect your eyes to avoid vision loss from macular degeneration and other eye diseases.
Researchers in France evaluated associations of lifetime exposure to ambient UV radiation with cataract surgery and diagnosis of macular degeneration among 963 residents of the Bordeaux region who were aged 73 or older. Estimated lifetime UV exposure was based on a survey of the participants and satellite-based data of ground UVR, and participants were then divided into three UVR exposure groups: lower quartile, intermediate quartiles, and upper quartile.
Study participants in the upper quartile of lifetime ambient UVR exposure had more than 50 percent greater odds of having had cataract surgery compared with participants in the intermediate quartiles of UVR exposure. Participants in this group also had more than 50 percent greater odds of being diagnosed with early AMD.
Surprisingly, participants in the lower quartile of UVR exposure also showed a significantly increased risk for early AMD compared with those with medium lifetime UV exposure.
The study authors concluded their research confirms results of earlier studies that show a high lifetime exposure to UV radiation increases the risk of cataracts and macular degeneration. The results of this study also suggest the risk for early AMD may be elevated among people who have a lower-than-medium exposure to UV rays throughout their lifetime. More research will be needed to confirm these latter results.
Blood Pressure Drugs Linked to Higher Risk for
Age-Related Macular Degeneration
July 2014 Taking vasodilators and oral beta blockers for high blood pressure has been associated with a higher risk for developing age-related macular degeneration (AMD).
High blood pressure must be controlled for good health, but the medications may increase risk of eye disease.
Analysis of data from the long-term Beaver Dam Eye Study of nearly 5,000 people found that taking vasodilators such as Apresoline and Loniten seems to bring a 72 percent greater risk of early-stage AMD. In fact, among those taking a vasodilator medication, 19.1 percent developed the eye disease.
And taking oral beta blockers such as Tenormin and Lopressor seems to increase the risk of neovascular AMD by 71 percent.
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The researchers suggested that further clinical studies be conducted to replicate the results and to find out why taking these medications increase AMD risk, before changing anyone's blood pressure medication.
A report of the analysis appeared online recently in the journal Ophthalmology.
Could Eye Drops Soon Replace Injections for AMD Treatment?
April 2014 One in five people over age 75 suffer from age-related macular degeneration (AMD), and currently the only effective treatment for the advanced "wet" form of AMD involves injections of medicines called VEGF inhibitors into the eye. But that might change in the near future.
It may soon be possible to treat macular degeneration with eye drops rather than eye injections.
Researchers at University College London (U.K.) recently reported the results of animal studies that demonstrate it's possible to create formulations of tiny nano-particles loaded with the anti-VEGF drug Avastin and deliver significant concentrations of the drug to the back of the eye by means of topical eye drops.
Though additional studies are needed to see if the eye drops are effective at controlling wet AMD in humans, having a topical treatment would be welcome relief to people suffering from macular degeneration especially those who are leery of having eye injections and are frightened by the procedure.
Topical treatment with medicated eye drops also would likely make AMD treatment significantly more affordable.
The study report includes data showing that the Avastin-loaded eye drops successfully deliver a therapeutic dose of the drug to the retina, where it stops leakage from retinal blood vessels and halts the formation of new abnormal blood vessels that are the hallmarks of wet AMD and lead to severe vision loss.
The study authors say the new technology has been patented by University College London's technology transfer company, UCL Business, and the researchers are seeking partners to accelerate commercial development of the treatment. The study report appeared in the March 2014 issue of the nanotechnology journal Small.
Rapid Dark Adaptation Testing May Be New Way To Detect AMD
March 2014 It's been known for some time that age-related macular degeneration (AMD) significantly affects the ability to adapt to seeing in dimly lit environments such as when entering a dark movie theater or re-adapting to seeing a dark roadway at night after encountering another vehicle with bright headlights.
Difficulty in adapting to dark environments can be tested more easily now with a new device called AdaptDx.
But traditional methods for measuring dark adaptation (DA) take at least 30 minutes or longer to administer, making them impractical as a diagnostic tool during a routine eye exam.
Recently, researchers at Penn State College of Medicine tested a new, rapid method for measuring dark adaptation as a way to quickly detect AMD. They used a testing device called AdaptDx, which is designed to measure DA in 6.5 minutes or less. Normal DA was found in 19 of 21 of healthy subjects, and abnormal DA was found in 115 of 127 AMD patients, giving the device a diagnostic sensitivity of 90.6 percent and a specificity of 90.5 percent.
The study authors concluded that the performance of the AdaptDx testing device compares favorably with long-duration research methods for the measurement of dark adaptation and direct examination of the eye performed by a retina specialist, and therefore that this rapid dark adaptation test is useful for the detection of AMD.
The study was published online in February by Investigative Ophthalmology & Visual Science.
Digital Tablets Help Certain People With Moderate Low Vision
November 2013 People who have eye diseases that damage their central vision can again read quickly and comfortably by using digital tablets, according to a new study conducted at Robert Wood Johnson School of Medicine.
On average, patients with moderate vision loss significantly increased their reading speed and comfort using an iPad digital tablet.
The researchers think that other tablets that feature back-lit screens and font-enlargement capabilities would offer similar benefits.
All of the 100 participants in the study gained at least 42 words per minute when using the iPad2 set to 18-point font, compared with reading a printed book or newspaper. People with the poorest vision showed the most improvement in speed when using an iPad or Kindle, compared with print.
People With Wet AMD Show Greater Risk of Parkinson's Disease
October 2013 Researchers in Taiwan have discovered that people diagnosed with neovascular (or "wet") age-related macular degeneration (AMD) have a significantly greater risk of later developing Parkinson's disease than people without AMD.
A total of 877 Taiwanese Chinese subjects with wet AMD and 8,770 randomly selected control subjects without the eye disease were included in the study. All were followed for three years.
The incidence rate of Parkinson's disease among those with wet AMD was 5.3 per 1,000 person-years; in the control group without AMD, the incidence was 2.1 per 1,000 person-years. After controlling for other variables, the researchers found that subjects with wet AMD were more than 2.5 times more likely to develop Parkinson's disease during the three-year study period than those without macular degeneration.
Further study is needed to confirm these findings among other populations and to explore the underlying reason for this increased risk, said the study authors.
A full report of the study was published online last month by the American Journal of Ophthalmology.
Couch Potatoes May Run a Greater Risk of Age-Related Macular Degeneration
Is this you? Changing your lifestyle may be healthier for your eyes.
Recently researchers found that the presence of drusen in the eyes was associated with less physical activity, higher levels of serum triglycerides, lower levels of serum high-density lipoprotein cholesterol (HDL) and a larger waist circumference.
These are all obesity-related risk factors, but the study authors noted that they are all modifiable. So it's possible that a change to a more physically active, heart-healthy lifestyle could delay the formation of macular drusen and maybe even slow the onset of AMD.
A report of the 888-participant study was published on the website of the journal Investigative Ophthalmology & Visual Science in May.
Macular Degeneration May Be a Systemic Disease
July 2013 For many years, the general consensus has been that age-related macular degeneration (AMD) is a localized eye disease that affects only the central zone of the retina. But a new study concludes that AMD may actually be a systemic disease affecting (or even caused by) the body's adaptive immune system.
Researchers at the University of Copenhagen in Denmark analyzed T-cell populations in blood samples of 117 individuals with AMD and 106 control subjects with healthy eyes. T-cells are specialized white blood cells that mature in the thymus and play a central role in cell-mediated immunity. There are several types of T-cells, each with a distinct protective function.
In particular, the researchers wanted to determine whether age-related changes within T-cells in the blood were associated with an increased risk of macular degeneration.
In the study, this was indeed the case. Participants with the highest percentage of specific T-cell changes had an odds ratio for the presence of AMD of 3.2 relative to participants with no evidence of such changes.
The study authors concluded that the increase in aged T-cells they found circulating in the bloodstream of people with AMD supports the notion of macular degeneration being a systemic (rather than a localized) disease, and also suggests the adaptive immune system is implicated in the development of AMD.
A report of the study was published on the website of the journal Ophthalmology in June.
Rejuvenating "Cholesterol Eaters" in the Eyes May Slow AMD Vision Loss
May 2013 Just as cholesterol accumulates in blood vessels, it can also build up in the eyes, in tiny yellowish deposits called drusen. When drusen become large, typically they indicate age-related macular degeneration (AMD).
An eye affected by neovascular AMD, filled with abnormal blood vessels and yellow deposits called drusen. The white spot at the right is where the optic nerve leaves the eye. (Image: National Eye Institute)
It is unclear whether cholesterol buildup triggers AMD. But one theory says that large immune cells called macrophages which normally "eat" cholesterol and also limit the rampant new blood vessel growth that occurs with AMD become less efficient with age.
And a new study suggests that they become less able to process cholesterol as they normally would. Instead, the macrophages become inflamed and then actually encourage blood vessel growth.
The study included tests in cell culture as well as in mice. By treating macrophages with an LXR agonist, which turned on a particular gene within those cells, the scientists rejuvenated the macrophages so they were effective once more at stopping abnormal blood vessel growth.
"If we could prevent the blood vessels from growing, it would be better than trying to eliminate them after the fact," said study leader Rajendra Apte, MD, PhD, in a National Eye Institute press release. "LXR agonists or other drugs to help macrophages clear away cholesterol might help."
A report of the study appeared online in April in Cell Metabolism.
FDA Approves Vision-Monitoring System for Handheld Devices, for People with Retinal Diseases
April 2013 Soon, people with macular degeneration, diabetic retinopathy or other retinal diseases will be able to track their vision at home, to aid their eye doctor's efforts in managing their eye disease.
The system, called myVisionTrack, lets people assess their vision function on an iPhone or other handheld device with a patented shape discrimination test.
The device stores the test results and automatically contacts a health care provider if results indicate that visual function seems to be deteriorating.
myVisionTrack will be available only by prescription from a health care provider. See our earlier news item for more details.
Study Finds Aspirin Use Linked to Increased Risk of AMD
January 2013 A study has found that regularly taking aspirin increases the risk of neovascular age-related macular degeneration (AMD).
The study, led by Barbara E. K. Klein, MD, MPH, of the University of Wisconsin School of Medicine and Public Health, analyzed data from the Beaver Dam Eye Study, a longitudinal population-based study of age-related eye diseases conducted in Wisconsin.
Nearly 5,000 people participated at the baseline examination, ranging in age from 43 to 86. Examinations were performed every five years over 20 years, and participants were asked if they had regularly used aspirin at least twice a week for more than three months. The average duration of follow-up was 14.8 years.
Over the course of the study, there were 512 cases of early AMD and 117 cases of late-stage AMD.
The researchers found that regular aspirin use 10 years before the retinal examination was associated with late AMD (1.8 percent for aspirin users and 1.0 percent for non-users).
One subtype of late AMD, neovascular AMD, had a significant association with aspirin use: 1.4 percent of aspirin users had neovascular AMD compared with 0.6 percent for non-users.
There was no significant association for early AMD or geographic atrophy, the other subtype of late AMD.
"Our findings are consistent with a small but statistically significant association between regular aspirin use and incidence of neovascular AMD," the research authors concluded.
Previous studies of aspirin use and AMD have yielded inconsistent results. In fact, the results of the Klein et al. study contradict the recent findings of Emily Y. Chew, MD, deputy director of the Division of Epidemiology and Clinical Applications, National Eye Institute.
Speaking at the 2012 annual meeting of the American Academy of Ophthalmology in November, Dr. Chew presented data from AREDS (Age-Related Eye Disease Study) and the follow-up study, AREDS2, which found that aspirin use did not increase the risk of developing AMD.
However, if further studies confirm the Beaver Dam Eye Study findings led by Dr. Klein, developing ways to slow the effect, especially for people who use aspirin to help prevent cardiovascular disease, will be of particular importance in the study and treatment of neovascular AMD.
The Klein et al. study was published in the Journal of the American Medical Association in December 2012.
Chemical That Helps Blind Mice See Light May Help
People With Vision Loss
BERKELEY, Calif., August 2012 When injected into the eyes of genetically blind mice, a chemical called AAQ can make cells in the retina sensitive to light, enabling vision. This is an amazing finding of recent research at the University of California, Berkeley, in collaboration with other groups.
During the experiment, the previously blind mice's pupils contracted in bright light, and they displayed the light avoidance typical of mice that can detect light.
Injecting the AAQ molecule into the eye may have several advantages over other, more permanent sight-restoring methods, such as implantation of light-sensitive chips and use of gene therapies or stem cell treatments.
The chemical does wear off over time, so regular injections would be required. But the dosage could be altered, it could be used in combination with other measures and it could be discontinued if desired.
People who could benefit from AAQ include those with retinal diseases such as retinitis pigmentosa and age-related macular degeneration.
New Statistics Show Big Increase in Macular Degeneration
in the United States
CHICAGO, June 2012 Since 2000, the number of people age 50 and older with late age-related macular degeneration (AMD) has climbed by 25 percent, to 2,069,403.
This startling increase was documented in "Vision Problems in the U.S.," a report released by Prevent Blindness America and the National Eye Institute and compiled by researchers from Johns Hopkins University.
Download these new statistics on age-related macular degeneration, myopia, cataracts, glaucoma and other vision problems.
The report showed large increases in other vision conditions, too. Diabetic retinopathy, for example, has risen a whopping 89 percent in people aged 40 and older. For open-angle glaucoma and cataracts, the increases were 22 percent and 19 percent. And 23 percent more people 40 and older are blind or visually impaired.
A new searchable database lets you research the new statistics on AMD, cataracts, glaucoma, diabetic retinopathy, myopia, hyperopia, blindness and vision impairment. You can search by state, age, gender and race; and you can obtain comparisons across vision problems.
Researchers are also looking at the costs of these vision problems to our health care system and our society. A report of their economic impact will be available soon.
Oscar-Winning Actress Develops Age-Related Eye Disease
Dame Judi Dench at the Berlin premiere of "Notes On A Scandal" in 2007. (Image: Pascal Le Segretain)
LONDON, February 2012 Dame Judi Dench has revealed that she has age-related macular degeneration (AMD) and has lost quite a bit of her eyesight.
In an interview published in the London newspaper The Mirror, she said she can no longer read scripts and must have a friend or relative read them to her.
She does not plan to retire anytime soon, however.
According to the interview, she has the wet form of AMD in one eye and the dry form in the other.
She has had injection treatments and hopes they are working to stop the progression of the disease.
Dame Judi said that bright light helps her to see better, and she also plans to buy a digital book reader so she can enlarge the type when reading.
She added that her mother had suffered from AMD as well.
Please click here for more macular degeneration news from 2011.
[Page updated November 6, 2014]
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