Age-related macular degeneration (AMD) is a medical condition with gradual onset which damages the centre of the visual field (macula or yellow spot) of the retina. There are dry and wet forms of macular degeneration. Symptoms of macular degeneration include blurring and distortion of central vision. In its early stages, macular degeneration might go unnoticed, as symptoms occur late in some patients. Potential causes and risk factors of dry or wet macular degeneration are smoking, high blood pressure, hereditary factors and a lack of vitamins and minerals. Several treatments options are available for macular degeneration. However, an active and healthy lifestyle is particularly important.
What is the Macula?
Macular degeneration is a complex eye disease affecting the tissue which lines the inner surface of the eye. The central area of the retina is also known as macula or yellow spot. This is because this area of the retina contains high concentrations of the yellow pigments lutein and zeaxanthin. These carotenoids, which are responsible for the yellow colour in the centre of the visual field, are secondary plant metabolites. Lutein and zeaxanthin can protect the eye from high-energy blue or ultraviolet light and free radicals.
The macula is actually a part of the brain and contains a high number of nerve cells. Even though the macula measures only 1.5 mm across, it contains many millions of photoreceptors. There are two types of photoreceptors in the eye (rods and cones). The centre of the macula is mostly made up of cones, which are responsible for colour vision and the perception of finer detail.
What is Age-Related Macular Degeneration?
Macular degeneration occurs if the photoreceptor cells in the macula deteriorate. Whenever the patient tries to focus on things or people, these appear blurred or even disappear from vision. It becomes particularly difficult to recognise faces or to read. The risk for macular degeneration increases with age. Age-related macular degeneration is the leading cause of severe vision loss in the western world.
Age-Related Macular Degeneration (AMD): Dry and Wet Forms
There are two main types of macular degeneration: dry and wet forms. The dry macular degeneration affects more people than the wet form.
85% of patients with age-related macular degeneration are affected by the dry form of the disease. Photoreceptors in the eye are slowly deteriorating due to the presence of deposits in the macula. However, the dry form can progress to wet form at any time.
The wet form of the age-related macular degeneration is more aggressive and usually progresses quickly. New, abnormal blood vessels are formed and can leak blood and fluid into the retina, coining the term “wet” macular degeneration. Photoreceptors responsible for acute vision are damaged, causing vision impairment. Wet macular degeneration is responsible for around 15 % of all cases.
Usually, age-related macular degeneration initially affects one eye of the patient more strongly, but according to experience, the other eye is subsequently damaged. Congenital forms of macular degeneration are rare.
Early forms of age-related macular degeneration (ADM) affect one in five people older than 65 years. By the age of 80, one in three suffers from AMD. The late stages of AMD, which cause vision impairment, affect around 1 % of people over 65 and 5 % of people over 80.
Age-Related Macular Degeneration (AMD): Symptoms
The first signs of this eye disease are usually blurred and/or distorted vision. Jumping letters and foggy vision are further symptoms which can be caused by macular degeneration. Many patients in the early stages of age-related macular degeneration notice that they cannot recognise signs from a distance or that everything they try to focus on appears blurred. These are clear warning signs! If you experience any of these symptoms, please see an ophthalmologist as soon as possible.
If you suspect macular degeneration, a simple test using the so-called Amsler Grid Eye Test can give you an indication if you suffer from this disease of the macula. Test your macula with the Amsler Grid Eye Test.
Risk Factors and Causes of Age-Related Macular Degeneration
Risk factors and causes of AMD include: older age, smoking, light skin, light eye colour, being female, hereditary factors, sunlight/daylight or artificial light with high level of UV or blue, arteriosclerosis and unhealthy diet. Reading does definitely not increase the risk for dry or wet macular degeneration. However, in the last few years, clinical studies showed that a deficit in certain vitamins or trace elements can promote the development of AMD.
There are also hereditary factors which contribute to the development of dry and wet AMD. Regular eye checkups by an ophthalmologist are essential, if other family members are known to suffer from this eye disease.
Free Radicals are also Damaging to the Eye
Our eyes work with highest precision, but they are exposed to tough conditions. Sunlight, especially the high-energy rays from the blue and ultraviolet part of the spectrum, can damage eyes and retinas. So-called “free radicals” are generated. These are highly reactive oxygen compounds which cause damage to the sensory cells of the eye.
The organism has developed many mechanisms to protect itself from the damaging influences of free radicals and the effects of high-energy wavelengths of the sunlight. In particular, lutein and zeaxanthin, which are present in the area of the macula responsible for acute vision, act protectively like “internal sunglasses”. Also important are vitamins and trace elements, which support the antioxidative activities in the eyes. These include the vitamins C, E and the trace elements zinc, copper and selenium.
As you grow older the body’s own defence and protection mechanism become exhausted. The concentrations of lutein and zeaxanthin, as well as the co-factors of antioxidative mechanisms in the macula decrease. Sensory cells degenerate and acute vision becomes impossible.
If lutein and zeaxanthin are given as a supplement, they are able to capture the free radicals and also filter out the harmful blue and UV light and act as a kind of internal sunscreen.
Age-Related Macular Degeneration (AMD): Treatment
The most important recommendation given for the treatment of AMD is an active and healthy lifestyle. This includes the activation of the circulation by physical activities and sport, smoking cessation and a healthy diet rich in vitamins.
Treatment of wet macular degeneration: Several treatment options are available for wet macular degeneration. Abnormal blood vessels can be ablated by laser treatment to prevent further leakage of fluids into the eye. However, the ablation of the tissue can only slow the disease progress. During photodynamic treatment, drugs are injected into the arm veins of the patient. These accumulate in the abnormal new blood vessels in the retina of the eye and can be activated by low-energy laser, causing a targeted ablation of this newly formed tissue. A further therapy option is an operation in which the abnormal growth is removed from the eye.
Treatment of dry macular degeneration: Dry macular degeneration can be influenced positively by a balanced nutrient intake, as can be achieved by a varied diet.
Magnifying reading aids are helpful to improve vision for both types of macular degeneration. This includes reading lenses, books in large print and screen readers, which strongly magnify letters.
The body’s defences, which protect our eyes from risk factors such as sun light and free radicals, can only operate if they receive sufficient protective compounds. Many of these compounds have to be taken up in the food, as the organism is unable to produce these.
Especially foodstuffs containing lutein and zeaxanthin, such as spinach, green cabbage or broccoli should therefore be regularly eaten. However, there are several reasons why it is not certain that the necessary level of micronutrients can be reached in our daily diet as we age.
Additional micronutrients can strengthen the natural protection mechanism of the eyes. They need to be delivered in the correct composition and in sufficient quantity. These include:
Antioxidative vitamins such as the vitamins C and E
Carotenoids such as lutein und zeaxanthin
Trace elements, in particular zinc, copper and selenium
Large scientific studies (e.g. ARED or LAST) have demonstrated the importance of these nutrients in the treatment of AMD.
Consult your Ophthalmologist
If you suspect a beginning macular degeneration, consult your GP or book an appointment with an ophthalmologist. You will be examined thoroughly and informed in detail about the prevention and treatment of age-related macular degeneration. It is recommended to adapt your lifestyle: Physical exercise and a balanced diet also benefit your heart, brain and vascular system - not just your eyes!