Dr. Grossman’s Blog

In the first study, Jennifer S.L. Tan, MBBS, BE at the University of Sydney, Australia and her colleagues evaluated data from 2,454 participants in the Blue Mountains Eye Study of men and women aged 49 and older. Those who consumed one serving of fish per week were shown to have a 31 percent lower adjusted risk of developing early AMD compared with those who consumed less.

In the second article, Elaine W. T. Chong, MD, PhD, of the Centre for Eye Research Australia and her associates evaluated data from 6,734 men and women aged 58 to 69 who participated in the Melbourne Collaborative Cohort Study. Dietary questionnaires completed between 1990 and 1994 were analyzed for the intake of various foods and individual fatty acids. Follow up examinations conducted between 2003 and 2006 detected 2,872 cases of early age-related macular degeneration and 88 cases of late disease.

A high intake of trans-unsaturated fats was associated with a significant increase in late macular degeneration, with those whose intake was categorized as among the top 25 percent of participants having a 76 percent greater risk than those whose intake was among the lowest fourth.

Olive oil emerged as protective against late disease. When those who reported consuming at least 100 milliliters per week olive oil were compared with those who consumed less than 1 milliliter per week, they were found to have a 52 percent lower risk of late AMD.

For early AMD, those whose omega-3 fatty acid intake was among the top 25 percent had a 15 percent lower risk compared with those whose intake was among the lowest quarter.

For more information on nutrition and macular degeneration and related research studies, see NaturalEyeCare’s Section on Macular Degeneration.

Seniors who perform poorly on tests of language, memory and concentration are more likely to be suffering from the early stages of age-related macular degeneration (AMD). 

A new study published in the Archives of Ophthalmology reviews the association between cognitive function decline and the onset of AMD.

“We found that those who have memory impairment were more likely to have early stages of macular degeneration independent of the effects of age, education and vascular risk factors,” said study co-author Dr. Tien Yin Wong, a professor in the department of ophthalmology with the Centre for Eye Research Australia at the University of Melbourne.

2088 participants aged 69 to 97 years who participated in the Cardiovascular Health Study were assessed for AMD.  Cognitive function was evaluated using the Digit Symbol Substitution Test (DSST) and the Modified Mini-Mental State Examination. Participants were also evaluated for dementia using detailed neuropsychological testing.

After controlling for age, sex, race, and study center, participants with low DSST scores were more likely to have early AMD than were participants with higher DSST scores.   In analysis that also controlled for education, systolic blood pressure, total cholesterol level, diabetes mellitus, smoking status, and apolipoprotein E genotype, the association was even stronger.

There was no association of dementia or Alzheimer disease with early AMD.

Read other studies on AMD

See tips on preventing vision problems with a focus on nutrition, exercise, lifestyle changes, and a positive mental approach to life at Natural Eye Care

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

A team of scientists and surgeons from the Institute of Ophthalmology at University College London and the Moorfields Eye Hospital in London has developed a stem cell therapy to treat age-related macular degeneration (AMD), the most common cause of vision loss in the elderly.
“Under the new treatment, embryonic stem cells are transformed into replicas of the missing cells,” writes The Times of London. “They are then placed on an artificial membrane which is inserted in the back of the retina.”

Pharmaceutical giant Pfizer announced this week that it will fund the development of the therapy; UCL professor Pete Coffey, who led the research team, predicts the therapy will be available as part of a simple, one-hour procedure within six or seven years.The researchers are applying for approval to conduct a clinical trial on humans; it would be just the second-ever trial conducted on humans using embryonic stem cells. Laboratory trials completed by the British team have demonstrated that stem cells can prevent blindness in rats with a similar disease to AMD. They have also successfully tested elements of the technology in pigs.

For natural approaches to help prevent the onset of macular degeneration as well as help preserve vision for those with macular degeneration, visit the Natural Eye Care web site

Researchers from Tufts University have found that a diet rich in omega-3 fatty acids and low in starchy carbohydrates can significantly reduce the risk of age-related macular degeneration (AMD).

The study, published in the journal Ophthalmology, is the first to calculate the combined effect of specific dietary nutrients and eating habits on a person’s risk for age-related macular degeneration.

During the study of 4003 participants in the ongoing Age-Related Eye Disease Study (AREDS), each dietary factor was assigned a percentile score; these scores were accumulated to find each participant’s compound score. The compound score was then evaluated for its association with the risk of AMD.

Researchers showed that vitamins C and E, zinc, lutein, zeaxanthin and the omega-3 fatty acids known as D.H.A. and E.P.A. were linked to lower risk for AMD.

The lowest risk of AMD was found in participants who regularly consumed a combination of these nutrients as part of a low-glycemic index diet.

The glycemic index (GI) is a measure of the effects of carbohydrates on blood glucose levels. Carbohydrates that break down rapidly during digestion, such as white bread and pastries, have a higher GI, as they release glucose into the bloodstream rapidly. Foods that break down more slowly, such as vegetables and proteins, have a lower GI value.

Read more about AMD on the Natural Eye Care website

Learn more about food sources for nutrients important for good eye health, including omega-3 fatty acids

SOURCE: “Dietary Compound Score and Risk of Age-Related Macular Degeneration in the Age-Related Eye Disease Study”, Chiu, et al, Ophthalmology, Volume 116, Issue 5, Pages 939-946.

Researchers from Tufts University have created a model to better predict a person’s risk for Age-related Macular Degeneration (AMD). 

This study, published in the May issue of Investigative Ophthalmology and Visual Science, was based on data from the 1,446 participants in the Age-Related Eye Disease Study (AREDS).  It shows how genetic, ocular, and environmental variables were evaluated and predictive models for prevalence and incidence of AMD were assessed. 

Researchers evaluated six criteria:

• age,
• sex,
• education,
• smoking status,
• body mass index, and
• supplementation with high-dose formulation of antioxidants and zinc (to slow progression of the AMD).

Although genetics play a large part in who will get AMD, there are lifestyle choices that can greatly influence a person’s risks for AMD.  Dr. Seddon noted that among individuals with one genotype studied (homozygous C3 risk genotype), the chance of suffering from the advanced form of AMD increased from approximately three times the risk for nonsmokers to almost 10 times the risk for smokers.

Study authors hope that learning more about how to predict who is at risk for AMD will give doctors and patients better information about how to better treat and even help prevent AMD.

Learn more about AMD and AMD prevention self-help tips

SOURCE:  Prediction Model for Prevalence and Incidence of Advanced Age-Related Macular Degeneration Based on Genetic, Demographic, and Environmental Variables, Seddon, et al, Investigative Ophthalmology and Visual Science. 2009;50:2044-2053.

Antioxidant and omega-3 supplements continue to be a simple, low-cost, effective therapy for AMD

A study designed to measure changes in visual function in subjects with atrophic (dry) age-related macular degeneration (AMD) found that three-quarters of the subjects receiving a nutritional supplement demonstrated stabilization or improvement of visual acuity at 6 months.

Dry, atrophic, or non-exudative, AMD is the most common form of macular degeneration.  Risk factors for dry AMD include:

• age greater than 50
• Caucasian race
• poor nutrition
• smoking
• atherosclerotic vascular disease
• genetics 
• sunlight exposure.

Multiple studies have suggested that nutritional factors can play a significant role in slowing the onset or limiting the effects of AMD.  The Taurine, Omega-3 Fatty Acids, Zinc, Antioxidant, Lutein (TOZAL) study tried to identify the potential benefits of a new supplement designed to limit the risk of AMD and progressive vision loss.

In this study, published in BMC Ophthalmology, 37 mixed gender patients (average age 76 years) at 5 independent study sites received a nutritional supplement specifically formulated to combat AMD.   This supplement included natural beta-carotene, vitamins A and E, zinc, and copper.   Results were compared to subjects in other tests who had been given placebos.

76.7% of subjects receiving the nutritional supplement demonstrated stabilization or improvement of visual acuity at 6 months.

Read other studies about AMD

Learn more about antioxidants and food sources for nutrients important for good eye health

SOURCE:  TOZAL Study: An open case control study of an oral antioxidant and omega-3 supplement for dry AMD, Cangemi, BMC Ophthalmology 2007, 7:3doi:10.1186/1471-2415-7-3.

Age-related macular degeneration (AMD) is the leading cause of vision loss in aging Western populations.   A study measuring the benefits of lutein found that consuming lutein nutritional supplements improves visual function and symptoms in those suffering from AMD.

90 participants with AMD participated in a trial conducted at a midwestern Veterans Administration Hospital from August 1999 to May 2001.

For 12 months, patients in Group 1 received lutein supplements; in Group 2, a lutein plus an antioxidant/vitamin/mineral supplement; and in Group 3, a placebo.

Researchers found that participants in groups 1 and 2 displayed improvements in mean eye macular pigment optical density, visual acuity, and contrast sensitivity.  Patients who received the placebo had no significant changes in any of the measured findings.

The study authors concluded that visual function is improved with lutein alone or lutein together with other nutrients.

Lutein is a naturally occurring carotenoid, and is found in green leafy vegetables such as spinach and kale.

Learn more about lutein and other nutrients important for good eye health

Read more about macular degeneration (AMD)

SOURCE:  Double-masked, placebo-controlled, randomized trial of lutein and antioxidant supplementation in the intervention of atrophic age-related macular degeneration: the Veterans LAST study (Lutein Antioxidant Supplementation Trial), Stiles, et al, Optometry. 2004 Apr;75(4):216-30.

Researchers predict age-related macular degeneration (AMD) will increase substantially by 2050, as the U.S. population ages, but the use of new and existing therapies can mitigate the effects of the condition.

A significant preventative therapy named in this study is the use of antioxidant vitamins to slow the progression of AMD from early to late stages.  Other treatments reviewed include laser and photodynamic therapies and anti-VEGF injections.

Scientists from the Research Triangle Institute International in North Carolina simulated cases of early AMD, choroidal neovascularization (CNV), geographic atrophy (GA), and AMD-attributable visual impairment and blindness with 5 universal treatment scenarios:

1. no treatment;
2. focal laser and photodynamic therapy (PDT) for CNV; 
3. vitamin prophylaxis at early-AMD incidence with focal laser/PDT for CNV; 
4. no vitamin prophylaxis followed by focal laser treatment for extra and juxtafoveal CNV and anti-vascular endothelial growth factor treatment; and 
5. vitamin prophylaxis at early-AMD incidence followed by CNV treatment, as in scenario 4.

From the results of this analysis, the researchers predicted that cases of early AMD will increase from 9.1 million in 2010 to 17.8 million in 2050 across all scenarios, but that existing medical therapies have the potential to reduce the visual impairment and blindness attributable to AMD by as much as 35 percent, translating to 565,000 fewer cases of visual impairment and blindness in 2050.

Learn about good food sources of antioxidants

Read about antioxidant vitamins important in the treatment of macular degeneration

SOURCE:  Forecasting age-related macular degeneration through the year 2050: the potential impact of new treatments, Rein, et al,  Arch Ophthalmol. 2009 Apr;127(4):533-40.

Although individuals with age-related macular degeneration (AMD) lose central vision, their peripheral vision often remains intact.   The Macular Disease Society (based in the UK) has developed a training scheme to help people use the undamaged parts of their eyes to read and identify faces. 

According to their research, people can be taught to use their peripheral vision to compensate for damage to their central vision, using “eccentric viewing” and “steady eye techniques”.   When someone with central vision loss looks directly at an object it may disappear or appear distorted, but when they look above, below, or to one side of it, they see it more clearly.

Eccentric viewing helps people learn where to focus their gaze to make their vision better.  Once this position is identified, they can be taught how to read again using the steady eye technique:  instead of moving the eyes from left to right to read a sentence, the person can keep their eyes completely still and move the text to the left so that each word in turn moves into the area of best vision.

Learn more about macular degeneration

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

Long-term heavy smokers have a 2.5 to 3.5 times greater risk of losing vision from age-related macular degeneration, according to medical geneticist John R.W. Yates, Ph.D., of the University of Cambridge.

A study in the British Journal of Ophthalmology shows a strong link between smoking and age-related macular degeneration.  The study also shows the risks associated with exposure to second-hand smoke.

Researchers conducted a case-control study in four British counties to determine the relationship between smoking and either of the two forms of end-stage age-related macular degeneration — geographic atrophy and choroidal neovascularization.

Between 2001 and 2003, 435 participants with age-related macular degeneration were compared with 280 controls.  Of the 435 cases, 261 had choroidal neovascularization, 106 had geographical atrophy, and 68 had a mixed phenotype.   Smoking status was assessed by a questionnaire; smokers were defined as those who smoked at least one cigarette a day for a year.

Scientists found a statistically significant association between age-related macular degeneration and pack-years of smoking. Pack-years were defined as the number of packs smoked a day multiplied by the number of years smoked.

Specifically, for 40 or more pack-years:

• The risk was almost triple, compared with non-smokers, for age-related macular degeneration
• For choroidal neovascularization, the risk was more than double
• For geographic atrophy, the risk was more than triple.

Compared with non-smokers who weren’t exposed to second-hand smoke, the non-smokers who had such exposure had nearly twice the risk of having any form of age-related macular degeneration.

Learn more about macular degeneration including recommended self-help and nutrition to reduce your risk of blindness

Source:  “Smoking and age related macular degeneration: the number of pack years of cigarette smoking is a major determinant of risk for both geographic atrophy and choroidal neovascularization,” Khan, et al,  Br J Ophthalmol 2006;90:75-80.