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Review 8

גיליון 8 – חושים, ינו' 03

תזונה וראיה - פריצת דרך בטיפול, ד"ר מיכאלה גולדשטיין, פרופ' ענת לבנשטיין

Dr. Michael Goldstein, Prof. Anat Lowenstein Department of Ophthalmology, Centre Sourasky medical Center, Tel-Aviv

age-related macular degeneration (age-related macular degeneration = AMD) is a disease which is the reason why primary vision loss in older age western the role of diet in the development of this disease is of considerable interest both among patients and professional literature damage photoreceptor cells in the retina caused by oxygen and by free radicals, which are created by the absorption of light rays and processes metabolic normal retinal high levels of antioxidants < strong> (antioxidants) can significantly reduce the chances of age related Macular degeneration form advanced .

These results were published great article recently published in the journal Archives of Ophthalmology and a breakthrough in this disease (1). In this article is, people who are at high risk of developing advanced stages of degeneration age-related macular disease, which is the main cause of vision loss in older age in the western world, the chances of developing the disease was reduced by 25% if treated bulk of a combination of vitamin C, vitamin E, beta-carotene and zinc. High-risk groups (including people with intermediate stage AMD or advanced AMD in one eye) supplements reduced the chances of vision loss caused by advanced AMD by 19%. Patients without AMD or early AMD, supplements did not bring significant benefit. This study was conducted by the National Institute of Health in the US. In fact, this is the first time clearly proved, any food supplements can be effective in reducing the progression of the disease.

Current therapies today the disease: treatment laser and photodynamic therapy can only stop the progress, but do not take her healing

age related macular degeneration (age-related macular degeneration = AMD) The first sign and necessary existence the disease is the presence in the retina of yellow deposits under the retina called drusen drusen. these often exist in people over age 60, and can be detected during examination including pupil dilation. drusen in themselves do not usually cause a disturbance in vision, however, whether they are large or there are plenty, AMD progression prospects grow, which can lead to the most severe decline in vision. the study described three stages of AMD: 1. early AMD. these people have a small drusen or a few medium-sized drusen in one eye or both. In these patients there is no decrease in vision resulting from AMD. 2. AMD Medium Intermediate. These people have many medium-sized drusen, or at least one large drusen in one eye or both. These patients usually have no decreased vision, or that there is only a slight decrease. 3. Advanced AMD. These people in addition to the existence of drusen, they also have atrophied area in the center of vision in the retina, or their blood vessels grow beneath the retina patients (a condition called AMD, "wet"). In these patients there is usually a significant decrease in vision. Current therapies disease, laser therapy and photodynamic therapy can only stop the progression of the disease, but do not bring her healing (2,3). In fact is not entirely clear why or how can the size and number of drusen bring to advanced AMD, a condition that impairs central vision, precise, responsible for the daily activities of our daily life such as reading, driving, recognizing faces. One observation is that as drusen more and bigger is more likely to develop one of the forms of AMD (4). Think, one of the mechanisms for the formation of the disease is retinal damage from free radicals (5).

< strong> free radicals – the cause disease free radicals are oxygen molecules which lack an electron, causing them to be unstable. Free radicals react with other molecules in the body, preventing them to function properly. Free radicals are an integral part of our body: we produce them byproduct of the metabolism of oxygen. Because, and in the center of vision in the retina (macula), there is rich in oxygen metabolism, free radicals are formed in which large quantities. Normally, the body's natural defense against these radicals Usually they are received and are carried in the bloodstream by antioxidants (antioxidants), whom the person receiving the food. These antioxidant ingredients stick to the free radicals and neutralize them. An ordinary man faced with a certain amount of free radicals created naturally in the body. However, in modern life are chemicals pesticides, air pollution, exhaust fumes, cigarette smoke, and uncontrolled exposure to the sun, and those also create a large amount of free radicals, which are toxic, and the limited supply of antioxidant substances can not cope with them. Materials for weathering the non-evacuated accumulate so fundus precipitation Fixed who do not evacuate, as stated, by a layer of pigment beneath the retina which protects the retina, disease and retinal degeneration related to age may break out.

Macular Degeneration age-related in moderate drusen large )

macular degeneration age-related advanced stage (growth of blood vessels in patients )

the effect of diet on the degeneration Center evidence role of diet in the development of this disease raises both patients and medical literature professional interest. When we talk about nutrition and its effect on macular center of vision associated with age, this is a particularly antioxidants, there are also naturally in various foods and include vitamin C (ascorbic acid), vitamin E (alpha-tocopherol), beta-carotene, alpha-carotene , Likofnim, Lotiain, Ziaksntin, selenium and zinc. Most of them are in green leafy vegetables and corn, kiwi and many vegetables and fruits green, red or yellow. The reason, people think that these agents can be effective is, theoretically these materials can counteract the damage to cells caused by oxygen free radicals. The theory is that damage to the photoreceptor cells in the retina, retinal degeneration associated with age, caused by oxygen and by free radicals, which are created by the absorption of light rays and normal metabolic processes in the retina. Patients they have already advanced AMD in one eye, the risk of developing advanced AMD also eye second particularly high. The study in question tested a number of antioxidants and vitamins that are known to help control cells and healthy living condition. We looked at the importance of zinc, a mineral concentration, which is the pigment layer beneath the retina (known as a protective layer of the retina) high. The materials introduced into the study included 500 mg of vitamin C, 400 international units of vitamin E, 14 mg of beta-carotene 80 mg of zinc, and – 2 mg of copper (which is added to prevent copper deficiency can develop when you add a lot of zinc). The study was supported by a commercial company, which supplied the materials and supporting research. In fact, previous studies have shown that people who eat a diet rich in green leafy vegetables are less likely to develop AMD (6), but the quantities that were taken in this study is very difficult to reach by Nutrition only, without supplements. The study included 4757 participants, aged 55-80, at 11 centers worldwide. Participants were treated one of four treatments: 1. only 2 zinc and antioxidant vitamins alone 3. 4. combination of both placebo. The effectiveness of the treatment was found only in patients who began the study when they are at high risk of developing advanced AMD, ie those with AMD, "medium" and those with advanced AMD in one eye only. In these patients, when taken in combination of antioxidant vitamins and zinc has been a significant decrease in risk for advanced AMD. Only patients who took zinc had also decreased risk of developing advanced AMD, but this decrease was less significant. Notably, there may be medical reasons that can prevent people from taking such relatively large amounts of vitamins. For example, beta-carotene has been shown to increases the risk of lung cancer in smokers. Therefore, each patient receives a recommendation vitamins and zinc ophthalmologists his need to consult with your doctor and see what vitamins really allowed him to take in terms of overall condition. Arm H"ktrkt "the study found Shlautm supplements had no significance for the development or progression of AMD. A cataract is a cloudiness of the lens of the eye that interferes with vision. It should be noted that patients also reported a number of side effects. 7.5% of patients, for example, zinc (compared to 5% of the placebo group) developed urinary problems, which required hospitalization. Also, people who received zinc opened more anemic people in the Palestinian condition. There are two antioxidants more Lotiain and Ziaksntin, their concentration high in the central vision in the retina, and for them in the past, research studies, which included questionnaires for patients and blood levels, which are effective in the prevention of progression age-related macular degeneration, but these materials were excluded last and proven effectiveness is not clear (7). Due to these factors, the recommendation now is that everyone over age 55 should get an eye examination, including pupil dilation. If found to be relatively advanced stage of the disease (stage it has drusen are large, and changes in pigment) must take the vitamins above, after consultation and approval of the doctor.

References: 1. Age-Related Eye Disease Study Research Group. A Randomized, Placebo-Controlled, Clinical Trial of High-Dose Supplementation With Vitamins C and E, Beta Carotene, and Zinc for Age-Related macular degeneration and vision loss. Report No. 8. AREDS Arch Ophthalmol. 2001; 119: 1417-36. 2. macular photocoagulation Study Group. Laser photocoagulation for choroidal neovascularization Juxtafoveal: five-year results from randomized clinical trials. Arch Ophthalmol 1994; 112: 500-9. 3. Treatment of Age-related macular degeneration with Photodynamic Therapy (TAP) Study Group. Photodynamic therapy of subfoveal choroidal neovascularization in age-related macular degeneration with verteporfin: two-year results of 2 randomized clinical trials – TAP report 2. Arch Ophthalmol 2001 ; 119: 198-207. 4. Bressler NM, Bressler SB. Preventive Ophthalmology. Age-related macular degeneration. Ophthalmology 1995; 102: 1206-11. 5. S Beatty, Koh H, M Phil, Henson D, Boulton M. The role of oxidative stress in the pathogenesis of age-related macular degeneration. Surv Ophthalmol 2000; 45: 115-34. 6. Seddon JM, Aiani IGA, Sperduto RD , Hiller R, Blair N, Burton TC, Farber MC

2. Age-related Macular Degeneration advanced stage (growth of blood vessels in patients)