Macula degeneration is usually age-related, thus, is commonly called age-related macula degeneration or AMD. Macula degeneration is an eye disease involving the central portion of the retina. Retina is the area in the back of the eye where receives the light or image and relates it in electrical signals through the optical nerve to the brain. Therefore, damage of the macula can cause loss of central vision, which should be clear and sharp. The disease was not well known by the general public until the recent decades when its prevalence had continued to increase [1]. However, a report in 2011 showed that the prevalence of macula degeneration has begun to fall possibly because of individual’s healthier lifestyle [2].There are two types of AMD, namely, wet AMD and dry AMD. Wet AMD occurs rapidly with growing blood vessels behind the macula. These blood vessels are fragile and leak blood and fluid , which raise the macula from the retina that results in loss of central vision. On the other hand, dry AMD occurs gradually and damages the macula cells and results in blurred vision first and progressively in loss of vision. The patient with dry AMD might feel that he needs more light in reading or viewing. Dry AMD has three stages, namely, early, intermediate, and advanced, for the degree of damages to macula cells. Sometimes, the patient may have yellow deposit(s) behind his retina, which are called drusen. The sizes and numbers of drusen increase as the degree of dry AMD advanced. The dry AMD is more common than the wet AMD [3].The greatest risk factor of AMD is age. AMD generally affects female more than males. Other risk factors of AMD include smoking, obesity, white more than black, and a positive family history. However, more studies have found both AMD and cardiovascular disease share common risk factors [4, 5]. Thus, avoiding the risk factors of cardiovascular disease is likely helpful in preventing or reducing the risk of developing AMD. Consequently, National Eye Institute encourages individuals to eat healthy foods such as green leafy vegetables and fish, to stop smoking, to prevent hypertension, to avoid overweight or obesity, and to exercise regularly.
Studies have shown diabetes mellitus is positively linked to the prevalence of AMD [6]. In January 2011, Chiu CJ et al cited in an article that the glycemic index of foods is positively linked to the risks of diabetes mellitus, cardiovascular disease, and recently to AMD [7], like the cases with retinopathy, even in those patients without diabetes mellitus [8]. These findings underscore the reiteration by this author that repeated spikes of hyperglycemia result from carbohydrate consumption, particularly in excess, is the risk factor of many diseases including AMD, even before these individuals are diagnosed with diabetes mellitus. With diets high in carbohydrate consumed by a majority of the population, it is understandable that the mass of one’s beta cells is likely continuing to reduce because of damages to beta cells by repeated hyperglycemia after meal. The prevalence of diseases increases as the individual is aging. [9]
Studies have also found AMD is a result of inflammation. [10, 11, 12] Reports have also shown hyperglycemia is both inflammatory and pro-inflammatory, which increases inflammatory factors such as C-reactive protein and cytokines [13]. Therefore, an axis of unrestricted carbohydrate consumption — postprandial hyperglycemia — postprandial inflammation — development of diseases including diabetes mellitus, cardiovascular disease, and AMD is evident clinically. Preventing repeated hyperglycemia from dietary carbohydrates should be the first and ultimate step in preventing diseases including age-related macula degeneration..
Robert Su, Pharm.B., M.D.
References:
1. The Eye Diseases Prevalence Research Group “Prevalence of Age-Related Macular Degeneration in the United States.” Archives of Ophthalmology. 2004;122:564-572.
2. Crystal Phend “AMD Prevalence Falling in U.S.” Medical News, Ophthalmology. January 10, 2011.
3. National Institute of Health “Facts About Age-related Macula Degeneration.” Health Information.
4. Snow KK & Seddon JJ “Do age-related macular degeneration and cardiovascular disease share common antecedents?” Ophthalmic Epidemiology. Volume 6, Number 2.
5. Cimbalas A et al. “[Association of age-related maculopathy with ischemic heart disease and its risk factors in middle-aged population of Kaunas city].” Medicina (Kaunas). Medicina (Kaunas) 2004;40(7):671-6.
6. Kelin R et al. “Diabetes, hyperglycemia, and age-related maculopathy. The Beaver Dam Eye Study.” Ophthalmology. 1992 October; 99(100:1527-34
7. Chiu CJ and Taylor A. “Dietary hyperglycemia, glycemic index and metabolic retinal diseases.” Progress in Retinal and Eye Research. 30 (2011) 18e53
8. Su RK “Diabetes Mellitus: A Diagnosis Too Late. (1 of 3).” The Blog. Carbohydrates Can Kill. April 7, 2010.
9. Su RK “Diabetes Mellitus: A Diagnosis Too Late. (2 of 3).” The Blog. Carbohydrates Can Kill. April 14, 2010.
10. Kelin R et al. “Inflammation, complement factor h, and age-related macular degeneration: the Multi-ethnic Study of Atherosclerosis.” Ophthalmology. 2008 Oct;115(10):1742-9
11. Hollyfield JG et al. “Oxidative damage–induced inflammation initiates age-related macular degeneration. “Nature Medicine 14, 194 – 198 (2008)
12. Boekhoorn SS et al. “C-reactive Protein Level and Risk of Aging Macula Disorder.” Archives of Ophthalmology. Volume 125 No. 10, October 2007.
13. Su RK “Carbohydrates Can Kill: Hyperglycemia is problematic but preventable by restricting carbohydrates. (1 of 3).” The Blog. Carbohydrates Can Kill. August 16, 2010.
Follow Dr. Robert Su M.D. at :
http://www.carbohydratescankill.com
No comments:
Post a Comment