| Age related macular degeneration | |||||
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- What is age-related macular degeneration?
- Symptoms of age-related macular degeneration
- Causes of age-related macular degeneration
- Treatment of age-related macular degeneration
- Important age-related macular degeneration facts
What is age-related macular degeneration
Age-related macular degeneration (AMD) is a degenerative disease that affects the macular of the eye. The macular is a part of the central area of the retina and allows the eye to be able to view objects close up, to enable us to read and write and it also allows us to be able to see all the different colours.
If the cells of the macular become damaged and stops working properly, then the macular degenerates and it can cause blindness. If caught early, the progression of the disease can be slowed down.
Since AMD starts in one eye before it affects the other eye, it can sometimes make it more difficult to detect as the "good" eye often compensates for the vision difficulties in the "bad" eye.
AMD is the form of macular degeneration which occurs as a result of ageing. Macular degeneration is a broad term which described any type of degeneration of the macular due to any reason.
There are two types of macular degeneration (MD), which are defined by how the macular appears to the opthalmologist (eye specialist) viewing it the macular through their equipment:
- Dry (atrophic) - most common form of MD; causes gradular loss of central vision
- Wet (exudative) - least common form of MD; causes bleeding and scarring behind the retina (a leeking of the blood vessels), which can lead to loss of vision
Age-related macular degeneration is also shortened to ARMD.
Symptoms of age-related macular degeneration
- Difficulty reading, writing, embroidery, sewing or anything else that requires close-up work
- Blurry vision - object appear fuzzy and hard to distinguish
- Distortion of images - straight lines appear wavy or crooked
- Blind spot in the middle of vision
- Inability to distinguish different people
- Vision loss (final symptom)
Causes of age-related macular degeneration
While it is not yet known what the single cause of the degeneration of the macular is, there are a some factors which increase the risk of developing AMD:
- Age - as people get older the macular may be more likely to get damaged or degenerate in some way
- Gender - many more women than men seem to develop age-related macular degeneration
- Genetics - AMD can be inherited by a specific gene and passed though families
- Nutrition - studies have shown that deficits of certain nutrients may be a factor in development of age-related macular degeneration
- Obesity - studies have shown that being obese can lead to age-related macular degeneration progressing to a more severe level more quickly
- Smoking - some studies have shown that smoking is implicated age-related macular degeneration; smokers seem to be at a higher risk for developing age-related macular degeneration
Treatment of age-related macular degeneration
Diagnosis and testing
Once you have seen your regular doctor, you will be referred to an eye specialist (opthalmologist) who will examine both the eyes for any signs of age-related macular degeneration through the following:
- Eye chart testing - to determine how well you can view the letters in the eye chart from each eye and at different distances; this test shows how clear vision is and at which distance vision becomes distorted
- Eye exam - special eye drops will be administered to each eye (which do not normally cause any pain) which widen the pupil to allow the eye specialist to view your eyes through a magnifying lens machine for signs of age-related macular degeneration; vision may stay blurry after the eye exam, due to the effects of the eye drops, but this effect is temporary (although it is recommended to have someone take you home after the test)
- Fluorescein angiogram - in this test, a special dye is injected into a vein in the arm (fluorescein), which soon arrives in the vessels of the eye; this test is performed to look at the circulation of blood in the blood vessels of the retina; the dye highlights any abnormalities o damage to the macular or retina; as the dye passes through the retina, a special camera takes a series of images
- Indocyanine green (ICG) angiogram - in this test, another special dye is injected into a vein in the arm (indocyanine green) which soon arrives in the vessels of the eye; this test is performed to highlight the deeper layers of the retina and makes visible the source of the abnormal blood vessels (this dye may cause the skin and eyes to stay yellow for up to 24 hours after it is administered)
Note: a very small percentage of people react to the dye used in the angiogram tests - you should discuss any concerns about the dye with your doctor prior to having the test done
Conventional treatment
- Dry AMD - the US National Eye Institute' s Age-Related Eye Disease Study (AREDS) has shown that taking certain antioxidants (vitamin C, vitamin E, beta-carotene, zinc and copper) significantly reduces the progression of dry AMD to an advanced stage; once dry AMD receaches an advanced stage it does not respond well to any type of treatment and vision loss ensues
- Wet AMD - there are 4 proven and 2 experimental treatments - proven treatments means there is proven scientific backing
through research, whereas experimental means that the treatment is not yet proven (and dosage is not yet determined or it has too many side effects)
Proven Treatments
- Lucentis - this is a medication with proven results where 70-80% of people injected had improvement of symptoms, or at least no deterioration; this medication must be injected into the eye at regular intervals; this treatment is available through the PBS in Australia; vision is maintain in the large percentage of people taking this drug
- Photodynamic Therapy (PDT) / Visudyne Therapy - this is a combined medication and laser treatment therapy, which uses a laser to activate the medication Visudyne which closes leaking blood vessels and stops progression of Wet AMD; a course of treatments is required with close monitoring of symptoms; AMD patients usually still have vision loss for up to 6 months after treatment, after which vision usually stabilises and does not deteriorate any further
- Laser photocoagulation - this treatments consists of a high energy thermal light (laser) directed into the affected eye(s) which seals and destroys the damaged blood vessels; this is not a painful procedure; close monitoring is require after the procedure as reoccurence of AMD occurs in about 50% of people
- Retaane - this is an angiostatic cortisene derived from a steroid, but modified so that it causes less side effects; this medication is inserted into the back of the eye through a small tube but it needs to be repeated every 6 months; as this is not yet on the PBS and has a high cost associated with it
Experimental treatments - Avastin - this medication has similar effect to Lucentis; it is regularly injected into the eye (after it has been prepared and numbed) but there is not enough research to prove how safe or effective it is and how long treatment must be given; it was originally used as a cancer treatment and discovered to have some benefits for AMD
- Triamcinalone - this medication is a slow release steroid which has been used experimentally in conjunction with other proven treatments; it needs to be injected into the eye and its effects last for several months; it appears to increase the risk of glaucoma development and other side effects with repeated use
Alternative / complementary treatment
Before trying any type of alternative / complementary treatments, you must advise your doctor, as they may cause serious complications or side effects with any other medications you are taking, including death. You should determine your risks with advice from medical specialists.
- Exercise - people with age-related macular degeneration are recommended to incorporate some exercise in their day, to ensure there is good blood flow to the eyes
- Nutrition - a good diet, with proper nutritional basis is recommended for people with AMD
- Supplements - a large US study conducted by the National Eye Institute has confirmed that antioxidants can greatly reduce existing symptoms and prevent worsening of the condition (especially in those with dry AMD); supplements may be of use to people with mild to moderate AMD
(the supplements used were vitamin A, vitamin C,
vitamin E, zinc)
- Betacarotene - this is the precursor to vitamin A and is often used instead of vitamin A, as it has less toxicity when used in higher doses; this is a potent antioxidant which acts to prevent free radical damage to the macular (as well to every other cell in the body) and has been shown in major studies (along with other antioxidant vitamins) to slow the progression of AMD ; betacarotene supplements should not be used by those people who are current or previous heavy smokers or alcohol drinkers as a large recent study implicated a higher incidence of cancer in those people taking this supplement, but the study also recommended getting betacarotene from the food in the diet for these groups of people was safe and did not increase risk for cancer
- Bilberry - this herb has been used for centuries to treat eye conditions, which have a high level of anthocyanosides, the active component of the berry, an antioxidant; studies on animals have shown that bilerry can prevent age-related macular degeneration; people with diabetes should be careful taking this herb
- Coenzyme Q10 - a large study showed the supporting mitochondria with coenzyme Q10 (together with acetyl-n-carnitine and omega 3 fatty acids) decreased symptoms and slowed degeneration of the macular by over 20% in the group trialling the supplements, while the group receiving no vitamins had 10% degeneration in symptoms
- Ginkgo biloba - studies show that people who are supplemented with ginkgo biloba may have less deterioration of vision, and may even prevent vision loss
- Lutein - studies show people who have a diet rich in foods high in lutein have a lowered risk for developing age-related macular degeneration; lutein acts as a potent antioxidant preventing the retina and macular from getting damaged by free radicals; lutein is one of the natural pigments that colours the eye; lutein is found in broccoli, corn, egg yolks, grapes, oranges, spinach
- Omega 3 fatty acids - several studies have shown that those people with a health level of omega 3 fatty acids in their diet (from consuming oily fish such as salmon, tuna) have a lower risk for developing AMD; other studies also found that a healthy balance of omega 3 to omega 6 fatty acids was also a factor in reducing risk for AMD; a new study showed that omega 3 fatty acids should be obtained from DHA and EPA and not ALA, as ALA seemed to increase risk for developing AMD
- Vitamin A - this vitamin is a major antioxidant which acts to prevent free radical damage to the macular (as well to every other cell in the body) and has been shown in major studies (along with other antioxidant vitamins) to slow the progression of AMD
- Vitamin C - this vitamin is a major antioxidant which acts to prevent free radical damage to the macular (as well to every other cell in the body) and has been shown in major studies (along with other antioxidant vitamins) to slow the progression of AMD
- Vitamin E - this vitamin is a major antioxidant which acts to prevent free radical damage to the macular (as well to every other cell in the body) and has been shown in major studies (along with other antioxidant vitamins) to slow the progression of AMD
- Zeaxanthin - studies also show that people who eat foods high in zeaxanthin are also at a lowered risk for age-related macular degeneration; zeaxanthin is one of the natural pigments that colours the eye
- Zinc - this mineral is a major antioxidant which acts to prevent free radical damage to the macular (as well to every other cell in the body) and has been shown in major studies (along with other antioxidant vitamins) to slow the progression of AMD
Important age-related macular degeneration facts
- Some people's vision deteriorates really slowly over a long time, so they may not even realise their macular is degerating and that they are slowly going blind
- Degeneration of the macular can cause vision loss
- One in seven Australians over 50 will develop age-related macular degeneration
- Having any type of macular degeneration does not normally hurt, so that could be why most people do not even realise it is happening
- Regular eye examinations can detect age-related macular degeneration before it causes vision loss
- Wet AMD is more treatable than dry AMD before it progresses to an advanced stage
- An important study has shown that antioxidants such as vitamin A, betacarotene, vitamin C, vitamin E and zinc appear to have a beneficial effect on dry AMD and specifically on halting progress of vision loss
Last reviewed: 14 January 2007 || Last updated: 14 September 2007
Related Articles
references
- Brady LW, Heilmann HP, Molls M, Alberti WE, Richard G, Sagerman RH. Age-Related Macular Degeneration: Current Treatment Concepts. 1st Edition, 2000, Springer Publisher
- Cho E, Hung S, Willet WC, Spiegelman D, Rimm EB, Seddon JM, et al. Prospective study of dietary fat and the risk of age-related macular degeneration. Am J Clin Nutr . 2001;73(2):209-218
- Cho E, Seddon JM, Rosner B, Willett WC, Hankinson SE. Prospective study of intake of fruits, vegetables, vitamins, and carotenoids and risk of age-related maculopathy. Arch Ophthalmol. 2004 Jun;122(6):883-92. PMID:15197064
- Feher J, Kovasc B, Kovacs I, Schvoller M, Papale A, Balacco Gabrieli C. Improvement of visual functions and fundus alterations in early age-related macular degeneration treated with a combination of acetyl-L-carnitine, n-3 fatty acids, and coenzyme Q10. Ophthalmologica. 2005 May-Jun;219(3): 154-66
- Fursova AZh, Gesarevich OG, Gonchar AM, Trofimova NA, Kolosova NG.Dietary supplementation with bilberry extract prevents macular degeneration and cataracts in senesce-accelerated OXYS rats. Adv Gerontol. 2005;16:76-9
- Lim JI. Age-Related Macular Degeneration. 2nd Edition, 2007. Informa Healthcare
- Seddon JM, Rosner B, Sperduto RD, Yannuzzi L, Haller JA, Blair NP, Willett W. Dietary fat and risk for advanced age-related macular degeneration. Arch Opthalmol . 2001;119(8):1191-1199
To learn more, go to the following web sites
- Macular Degeneration Foundation (Australia)
- National Eye Institute (USA)
- National Institute of Health - Senior's Health (USA)
NOTE: Mega doses of any type of vitamin, mineral, amino acid or herbal supplement cannot cure illnesses and in fact can be very dangerous and produce toxic side effects and interfere with medicine you are taking. Always ensure you consult your doctor before taking any type of complementary supplements.
Disclaimer: This guide is not intended to be used for diagnostic or prescriptive purposes. For any treatment or diagnosis of illness, please see your doctor.
