The macula is found at the centre of the retina where incoming rays of light are focused. While it only has a diameter of 2 millimetres and occupies only 2% of the visual field, it contains 25% of the photoreceptor cells. These are what translate light energy into impulses which are carried along the optic nerve and into the brain.
The macula is highly metabolically active. It allows us to see what is straight in front of us, is necessary for detailed visual activities like reading and writing, and allows us to appreciate colour.
The macula is nourished by the retinal pigment epitheliumn (RPE) which lies under the retina. These cells deliver nutrients and clear metabolic waste.
The cells in the macula are very delicate and over many years deteriorate and may die off. This is called age related macular degeneration (ARMD). This form is called “dry” and is responsible for 90% of cases.
In 10% of cases the condition progresses. New blood vessels grow across the macula and can leak and scar it, causing sudden rapid loss of vision. This is the “wet” or “exudative” form.
Degeneration of the macula is the leading and fastest growing cause of severe vision loss in those over 55. It affects 15 million Americans. 16,000 people a year are registered blind in the UK because of it. Almost everyone over the age of 65 will have some changes in the macula.
Since the condition develops slowly, it is possible to stabilise or even to improve vision if caught early. Once it has advanced however, little can be done.
Symptoms Of ARMD
These include blurred or distorted vision, with objects appearing to have unusual shapes or sizes. Straight lines may appear crooked. Colour perception fades. There may be some sensitivity to light or see lights that aren’t there. As the condition progresses the central field becomes blank or is a dark blur. Vision is only clear in peripheral areas.
There are no effective conventional treatments, although drugs and laser surgery are sometimes used. Photodynamic therapy with the new drug Visudyne may help prevent blindness if caught in time.
The cause of ARMD is unknown but a number of possibilities have been put forward.
Retinal tissue is rich in fats. This makes them very vulnerable to free radical damage.
Sunlight is potentially harmful and can damage the retina over time by oxidising fats in the retina.
Melanin is the eyes’ protective pigment. This is needed in abundance to shield the maculae from excessive ultraviolet and blue light rays which do the damage. Light coloured eyes have less melanin than dark eyes so may be more at risk.
Another theory is that the antioxidant level in the RPE lessen, leaving it less able to remove waste products which accumulate and damage the maculae.
Whatever the cause, antioxidants play an important role.
Antioxidants Improve ARMD
A number of studies suggest higher intakes of antioxidant nutrients and high blood levels of antioxidants offer macula protection.
In one study after 18 months those with ARMD who took antioxidant supplements consistently, were 2½ times more likely to improve on visual acuity testing and 4 times less likely to deteriorate in their worst eye than those who took them less consistently.
A trial involving 421 patients found those with high blood levels of antioxidants had 70% less risk for developing the disease than those with low blood levels.
Zinc is important for good vision because there are enzymes that function in the retina that depend on it. In fact zinc is more concentrated in the retina than in any other organ.
A double-blind trial gave 80mg of zinc or placebo to 151patients for 2 years. The maculae of the zinc group deteriorated 42% less than the placebo group.
An important study was published last year in the Archives of Ophthalmology. 3,640 patients with ARMD were divided into 4 groups. The first took antioxidants containing 500mg of vitamin C, 400 units of vitamin E, and 15mg of beta carotene. The second group took 80mg of zinc with 2mg of copper. The third group took a combination of both and the fourth group took placebo. They were evaluated over 6 years.
The third group had a 25% statistically significant reduction in the chance of developing advanced ARMD compared to the placebo group. The risk of central vision loss was reduced by 19%. There were also impressive reductions in risk for the 1st and 2nd groups. The journal’s editorial wrote: “these results demonstrate impressive efficacy.”
Dr. Wright’s Successful Treatment
A pioneer in the treatment of ARMD with antioxidants is Jonathan V Wright. He wrote a paper in the Journal of Nutritional Medicine back in 1990.
He describes the case of Dr. Bittner who reported substantial improvement in his own vision with selenium and vitamin E in 1977. Wright passed this information on to others. One person improved so much his ophthalmologist thought his initial diagnosis must be wrong. Wright went on to add zinc and then taurine to the protocol. Taurine is highly concentrated in the photoreceptor cells.
In 1986 he gave a patient zinc and selenium intravenously because of her malabsorption problems. Her eyesight improved during the procedure. This encouraged him to treat everyone with these minerals by IV initially, with vitamin E and taurine orally.
In December, 2000 Dr. Wright updated his experience in treating this disorder in Nutrition and Healing newsletter. ARMD can be halted or reversed 70% of the time. He has found poor stomach function or digestive disorders in nearly everyone with this condition, hence the need for IV treatment until the digestive system can be improved. He now includes all essential minerals, B complex vitamins and other key nutrients for the eyes. This includes amino acids and testosterone for tissue regrowth.
The Digestion & Thyroid Link
Dr. Abel also believes that correcting the digestive system is vitally important in treating this disorder. In fact he says macular degeneration “is a disease of poor digestion.” This must be addressed first.
The late Dr. Gary Price Todd believed virtually everyone with ARMD had an underactive thyroid. He recommended using the Barnes test. After balancing the thyroid, nutritional support was provided. He found virtually all patients to be selenium deficient. 88% of his patients saw their vision improve significantly over a 2 year period.
Carotenoids To The Rescue
A 1994 study published in the Journal of the American Medical Association compared the diets of people with ARMD with 500 others without eye problems. Higher carotenoids were associated with a lower risk of the disease. Those in the highest quintile of dietary carotene had a 43% reduced risk compared to those in the lowest quintile.
The Harvard researchers then looked at specific carotenoids. Beta carotene lowered the risk of ARMD by 41%. The carotenes lutein and zeaxanthin did even better. Those with the highest intake of 5.8mg a day had a 57% reduced risk.
The macula is dense in yellow pigments which are derived primarily from lutein and zeaxanthin. These neutralise harmful light wavelengths and stabilises the RPE.
The researchers found those who eat leafy green vegetables like spinach, kale and collards have a far lower risk of ARMD.
The journal’s editorial stated that “not all antioxidants are created equal” and goes on to say that the study “supports the role of specific antioxidants” in preventing ARMD.
High risk groups for ARMD include smokers, postmenopausal women and those with light-coloured eyes. These were found to have significantly less of these pigments in their retinas.
A review of studies in the American Journal of Clinical Nutrition in 1995 concluded that “the combination of evidence suggests that carotenoids and antioxidant vitamins may help to retard some of the destructive processes in the retina and the retinal pigment epithelium that lead to age-related degeneration of the macula.”
The richest source of lutein and zeaxanthin is egg yolks. Kale has 158mcg per gram. This is followed by turnip greens 84.4, collard greens 80.9 and spinach 70.4. Broccoli, courgettes, corn, peas and brussels sprouts also have reasonable amounts.
Don’t Forget Bioflavonoids
These nutrients are important for maintaining the health of the blood vessels and are an important part of any preventative or healing programme. Of particular importance is bilberry, which can enhance the microcirculation of the retina, and ginkgo biloba. But other vitamin C-rich fruits such as berries, grapes, plums, blackcurrants, cherries and apricots should be eaten regularly.
Fish Is Good Too
A study published in the Archives of Ophthalmology found those consuming fish more than once a week were only half as likely to develop ARMD than those consuming it less than once a month.
Australian researchers found those that ate the most fish reduced the risk of advanced ARMD by half compared to those that ate it less than once a month, although it didn’t reduce the risk of the disease in its early stages.
Lack of omega3 fish oils appears to be a risk factor. 85% of patients over 70 saw an improvement in their vision with these fats. DHA is believed to improve the health of blood vessels leading to the retina, where it is also found in abundance.
Rose and Rose in their book Save Your Sight give the following daily nutritional prescription for macular degeneration:
Vitamin C 2000 mg
Bioflavonoids 200-400 mg
Beta-carotene 15,00-25,000 IU
Vitamin A 10,000-25,000 IU for 3 months after diagnosis
Lutein & Zeaxanthin 6-10 mg
Magnesium 300-500 mg at bedtime
Fish Oils - Follow directions on bottle
Vitamin E 800 IU
Selenium 200 mcg
NAC 500 mg 2-3 times
Taurine 500-1000 mg between meals
Garlic 1000 mg odourless
Zinc 15-30 mg
CoQ10 30-200 mg
Hydrochloric Acid 250 mg if needed.
Optometrist Dr Abel makes these supplement recommendations:
Vitamin A 10,000 IU
Beta Carotene 5000-10,000 IU
Lutein 6-20 mg
Vitamin C 1000-3000 mg
Vitamin E 400 IU
Magnesium 500 mg
Bilberry 100 mg twice a day
Ginkgo Biloba extract
Garlic 100-1000 mg odourless
Flaxseed oil 1 tablespoon
Fish Oil DHA 500 mg
Selenium 50-200 mcg
Taurine 2 mg
Chromium 200 mcg
Zinc up to 30 mg
Digestive Enzymes as required
This article was first published in Enzyme Digest No. 57, Summer 2002
Any health and medical information published on this website is not intended as a substitute for informed medical advice and you should not take any action before consulting with a health care professional.