Macular degeneration is a leading cause of blindness: How to prevent it

by Langis Michaud, The Conversation

Macular degeneration can result in blurred or no vision in the center of the visual field. Credit: Shutterstock

Jacques was a very active retiree. That ended one November morning as his life was suddenly turned upside down. When he woke that day, he could not see out of one eye. Panicked, he came to see me right away.

12 jun 2021--Jacques had been diagnosed with age-related macular degeneration (AMD) a few years earlier. His condition had been stable, but now it suddenly progressed to the most severe form of the disease, "wet degeneration." This stage is characterized by the sudden development of a network of new blood vessels that ooze into the deep layers of the retina, causing a rapid loss of functional vision in the affected eye.

An urgent referral to ophthalmology is made in cases like these because the window of opportunity for treatment is narrow. Immediate treatment usually results in the best prognosis. Jacques managed to get treatment within a few days.

The ophthalmologist gave him interocular injections of medication, but this only improved his vision slightly. Jacques was depressed and his anxiety was increasing. He felt useless and had lost considerable autonomy.

The loss of an eye is a traumatic event, regardless of the patient's age. While the significant negative psychological effects are well documented for older patients, recent publications also report the same adverse consequences in younger populations.

For example, the rate of depression is six times greater in those with significant vision loss than in the general population (25 percent versus four percent).

Hope for patients

So what can we do to help Jacques? We can't promise that his vision will be fully restored. Although injection treatments can be effective, the basic degeneration will not go away. The best option for Jacques is to refer him to a visual impairment rehabilitation centre where he will receive help from a variety of professionals.

At this centre, he will be seen by specialists trained to treat visual impairment and its repercussions on the lives of people who suffer from it, and on the people around them. Understanding this reality is the first step toward helping patients address their needs.

The next step, after providing psychological support to Jacques, is to optimize his visual condition. Optometrists who specialize in low vision can prescribe optical aids to help Jacques regain some of his visual function, including magnifiers, vision aids and specialized glasses that can be provided through a government program designed for this purpose.

Specialists in visual impairment rehabilitation (VIR) trained at the school of optometry of the University of Montréal (the only institution in Canada that offers a master's program in VIR), can then help Jacques learn new strategies to carry out his daily activities. Specialized educators can help him to use a computer and specific software. When needed, orientation and mobility specialists teach people with visual impairments methods how to safely orient themselves and get around whether on the street or in an unfamiliar environment.

Age-related macular degeneration (AMD) can result in blurred or no vision in the centre of the visual field. Credit: Shutterstock

A social worker, aware that the impacts of a visual handicap go far beyond the person experiencing it, will accompany Jacques during his rehabilitation process and communicate with his family. In short, Jacques will have a good support system and will be able to regain a certain level of autonomy in his life, which, in turn, will have a positive impact on his morale. Support groups can also help him in his efforts and if, thanks to effective injections, his visual acuity improves, he will be in a win-win situation.

However, Jacques still has other concerns about his disease. He is worried that his children will develop similar conditions, especially one of his sons.

Several risk factors

Age-related macular degeneration is aptly named: its prevalence increases with the age of the patients. Nearly one million Canadians— 300,000 in Québec alone— suffer from AMD. Of these, 10 to 15 percent have the wet form, like Jacques. AMD is the leading cause of blindness in people over the age of 65.

In addition to aging, other risk factors associated with the development of the disease include family history, ethnic origin (Caucasians and Northern Europeans are more affected), gender (women are more affected), atherosclerotic and vascular diseases, obesity and sun exposure (phototoxicity of the retinal cells).

Smoking also plays an important role. Consuming 25 cigarettes per day doubles the risk of severe damage. Exposure to second-hand smoke is also harmful. The chemicals absorbed during exposure to smoke increase the absorption of harmful sunlight by the retina by 1,000 times.

For Jacques' son, the risk of developing AMD is clear but so are his options. He will not be able to change his genes, prevent himself from aging or change his ethnicity or chromosomes. However, he can control the modifiable factors: he can quit smoking, control his weight and stay physically active.

Diet can play a preventive role. Reducing fat intake in the diet and ensuring adequate omega-3 consumption (forms of triglyceride, 800 mg DHA/EPA per day) are important. However, adding vitamins formulated for eye health to the mix is not recommended in Jacques' case. Vitamins are only effective in treating dry AMD in its middle stages, not for preventing it. However, they are one of the few ways Jacques can reduce the risk of having his other eye affected and losing all his functional vision.

It is imperative for both Jacques and his son to follow the doctor's recommendations on managing vascular problems (hypertension, cholesterol, diabetes). When poorly controlled, these conditions significantly increase the risk of developing wet AMD.

Remember, macular degeneration is first and foremost a vascular disease: the blood vessels are no longer able to nourish the retinal cells and no longer get rid of their metabolic waste efficiently. As a result, the cells die. New blood vessels develop, but they are fragile and, when they break, flood the retina with fluid.

Finally, both father and son will need to protect themselves from the sun's harmful rays, either with a transparent filter (UV400) in their regular prescription glasses or by wearing good quality sunglasses when they are outdoors. Their eye care professionals will be able to advise them about this.

Jacques' spirits are not high, but I have given him some hope that better days lie ahead. He knows he can count on a team of professionals to support him and that he will not be dealing with his condition alone. There is hope. And hope is the first thing that makes it possible to overcome the impacts of any disease.

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Provided by The Conversation 

Macular Degeneration: The 'See Food' Diet

25 july 2009--Current research suggests that a diet high in omega-3 fatty acids may help prevent one of the leading causes of legal blindness among the elderly. The related report by Tuo et al, "A high omega-3 fatty acid diet reduces retinal lesions in a murine model of macular degeneration," appears in the August 2009 issue of the American Journal of Pathology.

Age-related macular degeneration (AMD), loss of vision in the center of the visual field (macula) due to retinal damage, is one of the leading causes of legal blindness among the elderly. Approximately 10% of people from 66 to 74 years of age will develop some level of macular degeneration, making it difficult for them to read or even recognize faces.

A diet high in omega-3 fatty acids has been found to protect against a variety of diseases including atherosclerosis and Alzheimer's disease. Retrospective studies have suggested that diets high in fish oil or omega-3 fatty acids may also contribute to protection against AMD. A group led by Dr. Chi-Chao Chan at the National Eye Institute in Bethesda, MD examined the direct effect of omega-3 fatty acids on a mouse model of AMD. A diet with high levels of omega-3 fatty acids resulted in slower lesion progression, with improvement in some lesions. These mice had lower levels of inflammatory molecules and higher levels of anti-inflammatory molecules, which may explain this protective effect.

Tuo et al suggest that "a diet enriched in EPA and DHA can ameliorate the progression of retinal lesions in their mouse model of AMD" and that "the results in these mice are in line with the epidemiological studies of AMD risk reduction by long chain n-3 fatty acids." The results "further provide the scientific basis for the application of omega-3 fatty acids and their biologically active derivatives in the prevention and treatment of AMD." In future studies, Dr. Chan and colleagues plan to use this murine model "to evaluate [other] therapies that might delay the development of AMD." Their ongoing projects include the "testing of systematic delivered pharmacochaperones and antioxidative molecules, as well as intraocularly delivered gene therapies."

This work was supported by grants from The Intramural Research Program of the National Eye Institute, the National Institutes of Health, and the American Health Assistance Foundation.

Tuo J, Ross RJ, Herzlich AA, Shen D, Ding X, Zhou M, Coon SL, Hussein N, Salem Jr N, Chan C-C: A high omega-3 fatty acid diet reduces retinal lesions in a murine model of macular degeneration. Am J Pathol 2009 175: 799-807

Source:
Angela Colmone
American Journal of Pathology

The Magnifying Glass Gets an Electronic Twist

By ANNE EISENBERG
26 may 2008--PEOPLE who lose part of their sight to macular degeneration, diabetes or other diseases may now benefit from some new technology. Several portable video devices that enlarge print may help them make the most of their remaining vision.
Swipe one of the devices over an airline ticket, or point it at a medicine bottle on a shelf, and all of the fine print is blown up and displayed in crisp letters on a screen.
Sturdy desktop video-based systems that magnify print have long been available, but lightweight, portable devices have become popular only in the past decade, as the size of consumer electronics products in general has shrunk. The new hand-held models typically weigh 9 ounces or less and can enlarge the print on closeby or more distant objects: users can pass the magnifier over a menu in a dimly lit restaurant, for example, or aim it at a grocery display on a store aisle.
The tiny, high-resolution video camera within the device captures the image, and the electronics bolster the contrast in the display, making it easier to read words on the monitor.
Dr. Bruce P. Rosenthal, chief of low-vision programs at Lighthouse International in Manhattan, which offers services for people with vision loss, said the portable magnifiers, with their built-in illumination and powerful electronics, have many advantages over traditional optical devices like magnifying glasses. “Optical devices can’t increase the contrast like these devices,” he said. “Loss in contrast causes as many problems as loss of visual acuity.”
Electronics in the new devices can make black print darker, or switch black lettering on white to white lettering on black — which some people with macular degeneration prefer.
Dr. Rosenthal said the devices could help people with low vision continue with their normal rounds — for instance, shopping in the supermarket or reading a prayer book at a religious service. “One of the concerns we have in working with the visually impaired is depression,” he said. The more that people can complete everyday activities like everyone else, he added, “the more they can cope and feel that their lives are no different than others.”
The devices have a substantial drawback, however, when compared with a $40 magnifying glass: They typically cost $700 to $1,300, and Medicare and most private insurance plans usually do not pay for them, said Robert McGillivray, low-vision specialist at the Carroll Center for the Blind in Newton, Mass.
“But if the devices get you back to work, or help you with your education, or increase your pleasure in reading,” he said, “it’s well worth considering them.”
The gadgets have a bigger area of view than a traditional magnifying glass and allow for far more flexibility in viewing an image, Mr. McGillivray said. And while the cost is typically not reimbursable, “if people are looking for a job, they may be eligible for vocational rehabilitation funds,” he said.
“State agencies might provide them with this type of product if it helps them get or retain a job,” he added.
One new portable device is the Quicklook Focus ($995), which weights 8.8 ounces. It has a camera head that sends digital video to the display, where the image is magnified, said Fergal Brennan, a design engineer at Ash Technologies outside of Dublin, the manufacturer. Users can pass the camera over a document they want to read, or hold it up at arm’s length to read the print on more distant objects.
The camera focuses electronically at the touch of a button and has a range of magnification starting at three times the original print size. The device runs off its own battery for four and a half hours at full power and for up to seven hours when the brightness is turned down, he said.
THE Quicklook Focus should be available by mid-June, said James McCarthy, president of Freedom Vision, the Mountain View, Calif.-based distributor for Ash in North America (www.freedomvision.net).
Another new device, the SenseView Duo ($1,299), available at the end of this month, has two cameras — one for close-up reading of text, the other for viewing objects eight feet or farther away, like classroom blackboards, said Doug Geoffray, co-owner of GW Micro, the Fort Wayne, Ind.-based distributor of the devices in North America (www.gwmicro.com). The product is made by the HIMS Company of South Korea.
The SenseView Duo, with a liquid crystal display 4.3 inches wide, stores up to 20 images — for instance, a screen shot of a railway timetable. Users can enlarge the image, then scan through it, moving up and down or left and right to read all the information.
Video magnification devices are valuable products in a world of often-frivolous consumer electronics, said Dr. Rosenthal of Lighthouse International.
“One of the objectives of this new technology is to improve the quality of life for people with low vision,” he said. “That’s exactly what these products are starting to do.”

AAO: Triple Therapy Leads to Lasting Improvement in Macular Degeneration

NEW ORLEANS, Nov. 13 -- For many patients with choroidal neovascularization from age-related macular degeneration, a single cycle of photodynamic therapy, bevacizumab (Avastin), and intravitreal steroids led to sustained improvement in visual acuity, German investigators reported here.
Action Points
Explain to interested patients that one course of combination therapy with three forms of treatment has shown promise for producing lasting improvement in macular degeneration.
Note that the therapy was used in Germany and might not be consistent with treatment approaches in the U.S.
Note also that the findings were reported at a medical conference and as a published abstract and should be considered preliminary until they have appeared in a peer-reviewed journal.
After a mean follow-up of 62 weeks, improvement in visual acuity for 104 eyes in 104 patients averaged 2.1 lines (P<0.01), Albert J. Augustin, M.D., of Karlsruhe Clinic in Karlsruhe, Germany, reported at the American Academy of Ophthalmology meeting here.
Retinal thickness also decreased significantly (P<0.01).
Triple therapy was well tolerated, no severe systemic or optical adverse effects occurred, and intraocular pressure did not increase, he added.
"Ultimately, we must tailor therapy to suit the individual's disease characteristics, ability to visit the clinic, and treatment preference or feasibility," Dr. Augustin concluded.
Age-related macular degeneration has a multifactorial pathogenesis that involves hypoxia, oxidative pressure, inflammatory responses, and an altered balance of pro- and antiangiogenic factors that results in neovascularization, Dr. Augustin noted. An ideal therapy, he said, would include an antiangiogenic agent, an anti-inflammatory, and photodynamic therapy to treat existing choroidal neovascularization.
Dr. Augustin and colleagues have used triple therapy in more than 400 patients, and he reported results for patients who have been followed the longest. Treatment consisted of 70-second photodynamic therapy with verteporfin, followed an average of 16 hours later by intravitreal administration of 800 µg of dexamethasone and 1.5 mg of bevacizumab.
In addition to the improvement in visual acuity, retinal thickness decreased by an average of 195 µm. Five patients required a second cycle of therapy because of persistent choroidal neovascularization activity. Additionally, 23 patients (22%) received a second injection of bevacizumab.
The triple therapy results in significant and sustained improvement in visual acuity, has a good safety profile, is convenient for patients, and is cost-effective over time as compared with indefinite therapy, such as an anti-VEGF agent, Dr. Augustin concluded.
Dr. Augustin disclosed investigator and consultant relationships with Alcon, Allergan, Novartis, Pfizer, and QLT Phototherapeutics.Primary source: American Academy of OphthalmologySource reference: Augustin AJ, "Triple therapy: bevacizumab + photodynamic therapy + steroids" AAO Meeting 2007; Subspecialty Program -- Retina: 40-42.

Problem-Solving Treatment Helps Prevent Depression in Patients With Age-Related Macular Degeneration

August 8, 2007 — Problem-solving treatment (PST) may help prevent depression in patients with age-related macular degeneration (AMD), according to the results of a randomized controlled trial reported in the August issue of the Archives of General Psychiatry. This treatment prevented depressive disorders and loss of valued activities in the short term, but these benefits were not maintained over time, suggesting that booster treatments may be needed.
"Age-related macular degeneration is a prevalent disease of aging that may cause irreversible vision loss, disability, and depression," write Barry W. Rovner, MD, from Jefferson Medical College in Philadelphia, Pennsylvania, and colleagues. "The latter is rarely recognized or treated in ophthalmologic settings.... [AMD] provides an appealing model for depression prevention research because its severity is readily quantified, it affects men and women equally, and has no biological symptoms that overlap with depression and therefore avoids the problem of confounding behavioral outcomes with underlying disease symptoms."
At outpatient ophthalmology offices in Philadelphia, 206 patients aged 65 years or older were randomized to PST (6 home-based therapy sessions during an 8-week period; n = 105) or to usual care (n = 101). Participants were recently diagnosed with neovascular AMD in 1 eye and with preexisting AMD in the other eye.
The main endpoints were diagnoses of depressive disorders based on criteria from the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV); scores on the National Eye Institute Vision Function Questionnaire-17 (NEI VFQ-17), a subset of the 52-item scale; and rates of giving up valued activities. Short-term outcomes were evaluated at 2 months, and maintenance effects were evaluated at 6 months.
Compared with controls, the intervention group had a lower 2-month incidence rate of depressive disorders (11.6% vs 23.2%; odds ratio [OR], 0.39; 95% confidence interval [CI], 0.17 - 0.92; P = .03) and of giving up a valued activity (22 vs 37; OR, 0.48; 95% CI, 0.25 - 0.96; P = .04). Although most of these benefits had decreased at 6-month follow-up, patients who had received PST were less likely to have persistent depression (P = .04).
"Problem-solving treatment prevented depressive disorders and loss of valued activities in patients with age-related macular degeneration as a short-term treatment, but these benefits were not maintained over time," the authors write. "Booster or rescue treatments may be necessary to sustain problem-solving treatment's preventative effect. This study adds important new information to the emerging field of enhanced-care models to prevent or treat depression in older persons."
Limitations of the study include generalizability limited by the unique visual characteristics of the patient sample, the unclear effects of attrition, and the lack of a control treatment group receiving comparable attention without PST.
The National Institute of Mental Health, the National Eye Institute, and the Farber Institute for Neurosciences of Thomas Jefferson University supported this study. The authors have disclosed no relevant financial relationships.
In an accompanying editorial, Charles F. Reynolds III, MD, from the University of Pittsburgh School of Medicine in Pennsylvania, and colleagues note that teaching effective coping skills during brief, depression-specific, behaviorally oriented psychotherapy may be preferable to prescribing antidepressants.
"However, additional studies are needed to demonstrate durable protective effects," Dr. Reynolds and colleagues write. "Problem-solving therapy for primary care appears to be a good candidate for future testing, perhaps as a component of stepped-care interventions, in which patients first receive lower-cost, lower-intensity efforts, followed by stepped-up (more intensive) care based on need. Given the substantial barriers to good treatment of depression in old age, preventing depression may be a more sensible population-based approach."
The National Institute of Mental Health, the University of Pittsburgh Medical Center, and the John A. Hartford Foundation supported this editorial. The authors have disclosed no financial relationships.
Arch Gen Psychiatry. 2007;64:884-885, 886-892.

Immune Gene Variant May Cause Macular Degeneration

CAMBRIDGE, England, July 18 -- A new picture of age-related macular degeneration has emerged from studies here that found a gene for part of the immune system is significantly associated with the disease.
The gene that codes for part of the innate immune system, John R.W. Yates, MBBS, of the University of Cambridge, and colleagues, reported online in the New England Journal of Medicine. A variant in the C3 complement gene "is likely to have a causal role in the disorder," they said.
Their study was released early in conjunction with two other reports of genetic links to disease, both of which used the new technique of genome-wide association scanning.
Dr. Yates and colleagues, on the other hand, used similar microarray methods in sequential case-control studies, but focused more sharply on variations in the complement genes C3 and C5, rather than the whole genome.
For their first study, the researchers evaluated 446 volunteers with end-stage age-related macular degeneration (either geographic atrophy or choroidal neovascularization) and 267 controls, who were spouses of the index patients.
They compared the frequencies of 12 single nucleotide polymorphisms (SNPs) that span the two immune system genes and found no suggestion of an association with the C5 gene.
But a polymorphism dubbed rs2230199 in the C3 gene -- which changes the electrophoretic character of the gene from "slow" to "fast" -- showed significant evidence of an association with the disease (P<0.001).
The "slow" form of the gene has been associated with better graft survival in kidney transplants, while the "fast" form has several associations with disease, the researchers said.
When the "fast" allele was tested in another group -- of 157 cases and 83 controls -- the association was even stronger, at P=5.9X10-5, Dr. Yates and colleagues said.
Finally, the association was tested in a Scottish cohort of 244 people with late-stage age-related macular degeneration, 261 with age-related maculopathy (an early form of the disease), and 351 controls.
That analysis also found the "fast" allele was significantly associated with disease, at P=5.9X10-5, the researchers said, although it was not associated with age-related maculopathy.
When all the test groups were combined:
Having one copy of the "fast" allele increased the risk of disease by 70%, compared with people with two copies of the "slow" allele. The odds ratio was 1.7, with a 95% confidence interval from 1.3 to 2.1.
Having two copies of the allele nearly tripled the risk. The odds ratio was 2.6, with a 95% confidence interval from 1.6 to 4.1.
The population attributable risk associated with the "fast" allele -- the risk that would be eliminated if the alleles did not exist -- is 22%, the researchers said.
The findings "provide conclusive evidence" that the complement system plays a central role in the development of age-related macular degeneration, the researchers concluded.
The study was supported by the U.K. Medical Research Council, the Chief Scientist Office of Scotland, the Macular Vision Research Foundation, the Wellcome Trust, the Juvenile Diabetes Research Foundation, and the Biotechnology and Biological Sciences Research Council. Co-author Baljean Dhillon, F.R.C.S., F.R.C.Ophth., reported financial links to Novartis and Pfizer. No other potential conflict of interest was reported.Additional source: New England Journal of MedicineSource reference: Yates JRW et al. "Complement C3 Variant and the Risk of Age-Related Macular Degeneration." N Engl J Med 2007;357.

Beta carotene pills may not save vision

Carrots, rich in beta carotene, long have been thought to sharpen eyesight, but a new study suggests that beta carotene pills are powerless against a common type of vision loss among older people. Age-related macular degeneration is the leading cause of blindness in people 65 and older. The condition blurs the center of the field of vision, making it difficult to read, drive, thread a needle and even recognize faces. It affects more than 10 million Americans and there is no cure.
An earlier large study had shown that beta carotene — when taken with certain vitamins and zinc — could slow or prevent vision loss in people with age-related macular degeneration. Commercial formulations of the eye-protecting combination vitamins are sold over the counter.
But the new study found no benefit for beta carotene supplements alone against the disease.

http://news.yahoo.com/s/ap/20070313/ap_on_he_me/diet_beta_carotene