Age-related macular degeneration (AMD): symptoms, causes & treatment
Age-related macular degeneration (AMD) – it is not for nothing that this eye disease is feared. It is one of the most common causes of new blindness in old age. This article explains what this disease is, how AMD manifests itself symptomatically and what treatment options are available.
What happens with age-related macular degeneration?
The macula lutea – also known as the “sharpest point of vision” or yellow spot – is located on the retina of the eye. It is of enormous importance for vision and is responsible for color and detail vision, among other things. Intensive metabolism of the photoreceptors (light-sensitive cells) takes place in the macula. In a healthy eye, the degradation products are disposed of by the pigment epithelium.
This metabolic transport is impaired in AMD. The disposal of degradation products is inhibited, resulting in deposits of degradation products under the retina. During an examination, the deposits become visible as yellow spots – these are also known as “drusen”. If the drusen multiply or increase in size, this can impair the function of the retina and ultimately lead to visual impairment.
Forms of AMD
A distinction is made between two different forms of age-related macular degeneration: Dry senile AMD and wet senile AMD. In 10-20% of those affected, wet AMD develops from the dry variant.
Dry senile macular degeneration
The dry form is characterized by a slowly progressing course of the disease. The increased deposits (drusen) mean that the retina is insufficiently supplied. As a result, the light-sensitive cells are destroyed. In the dry form, both eyes are usually affected.
Wet senile macular degeneration due to ageing
The much rarer form: Wet AMD, which progresses faster and more aggressively. Within a few days or weeks, vision can be severely impaired. The wet form usually only affects one eye.
As a result of the restricted metabolism between the choroid and retina, growth hormones are produced. This creates new blood vessels under the retina, which grow together with the retina and are intended to supply it better. Fine tears in the pathologically formed vessel walls can cause wound fluids to enter the retina, resulting in macular edema. This often causes irreversible damage to the photoreceptors.
Symptoms of AMD at a glance
Various symptoms can occur as a result of AMD. The symptoms are often only noticed at a late stage. They particularly affect central vision. Those affected complain of:
- Blurred vision
- Distorted view
- Deterioration of color vision and contrast perception
- Gray spot or veil in the middle of the visual field
- Increased sensitivity to glare
The further AMD progresses, the more severe the symptoms become. While perception in the central field of vision is poor in the initial stage, vision can be so impaired in advanced AMD that objects in the central field of vision can no longer be perceived at all. Ultimately, untreated AMD can lead to blindness in the central field of vision. As only the macula is affected, the outermost field of vision is usually retained even in the event of blindness. However, this still causes massive restrictions in the everyday life of those affected.
Causes and risk factors
The causes and risk factors for age-related macular degeneration have not yet been conclusively clarified. However, age is a significant factor: Most AMD occurs after the age of 60. It is sometimes even assumed that AMD can affect all people, as long as a certain age is reached. Some factors probably influence the time of onset:
- Smoking
- Increased UV radiation
- Overweight
- High cholesterol levels
- High blood pressure and cardiovascular diseases
- Hereditary factors, family history
Diagnosis of AMD
The ophthalmologist can detect a change in the macula even before those affected experience the first symptoms. Various methods can be used to make a diagnosis.
- Ophthalmoscopy (examination of the back of the eye): Using a microscope, the doctor can examine the back of the eye and the macula, revealing the drusen as yellow dots.
- Eye test: On an eye chart, signs on a grid are to be viewed and described by the patient (Amsler grid).
- Optical coherence tomography (OCT): The macula can be imaged using a laser, revealing any changes.
- Fluorescein angiography: An injected dye makes altered vessels in the macula visible.
Treatment of age-related macular degeneration: treatment of AMD
When treating AMD, a distinction must also be made between dry and wet AMD. Although dry AMD has a slower progression and manifests itself with milder symptoms, it cannot be treated. In contrast, there are different treatment methods for the wet – and significantly more aggressive – variant.
A complete cure is not possible for either variant of AMD, as the photoreceptors are irreversibly damaged and there is still no way to replace them. Nevertheless, the progression of AMD can be inhibited or slowed down if necessary.
Treatment of dry senile AMD
High-dose food supplements are sometimes advertised. High doses of these supplements should be taken in consultation with your doctor. These include, for example
- Vitamin C
- Vitamin E
- Beta-carotene
- Zinc
An AREDS study came to the conclusion that in the presence of medium-sized or large drusen, a preventive effect can be observed with regard to progression. However, if no or only small deposits are visible, there is no prophylactic effect.
In some cases, preparations such as luthein or zeaxanthin are advertised for the purpose of preventing AMD. However, these dietary supplements lack scientifically proven effects in terms of inhibiting the progression of AMD.
Treatment of wet senile AMD
Wet AMD can be stopped or inhibited using various methods. Surgery to remove the new blood vessels is possible, but is usually performed as a last resort. Other treatment options can be used beforehand:
- Anti-VEGF (Vascular Endothelial Growth Factor) therapy: The drug is injected into the affected eye and can slow down or inhibit the progression of AMD.
- Photodynamic therapy (PDT): An agent injected into the vitreous body can use laser irradiation to ensure that the pathological growth of the vessels in the macula is inhibited.
- Laser therapy: The uncontrolled overgrown vessels are destroyed by heating with an argon laser (heat laser).
Preventing age-related macular degeneration
There are currently no reliable preventative measures against AMD. Nevertheless, it is advisable to avoid the suspected risk factors:
- Sunglasses with UV protection
- Healthy lifestyle with a balanced diet
- Avoid smoking
Regular check-ups are also a good idea. If you are diagnosed, you can gradually adjust to the disease and adapt your environment – whether by adjusting the lighting conditions in your home or changing light
