Age-related macular eye degeneration (AMD) is an eye condition that occurs in people that are over 50 years old. This eye condition affects the eye’s sharp, central vision as the damage is done to the macula, which is found in the retina’s centre. The macula is responsible for seeing fine details of images. If allowed to persist, AMD can bring challenges in doing daily activities as the eye’s vision may become blurry or distorted. If the condition is overlooked for a long time, it may result in complete loss of vision.
Causes of Age-Related Macular Degeneration
According to ophthalmologists from Singapore Eye care centre AsiaRetina Age-related macular degeneration can be caused by several factors:
- Age (50 years and above)
- High levels of cholesterol
- Poor nutrition
- Unprotected and prolonged exposure of the eyes to sunlight
Types of Age-Related Macular Degeneration
There are two types of age-related macular degeneration:
- Dry AMD – this type of AMD happens when the macula’s light-sensitive cell gets damage and destroyed, causing yellow fatty particles (drusen) to pile up in the retina.
- Wet AMD – this type of AMD is more critical as compared to dry AMD. Wet AMD occurs when tiny abnormal blood vessels grow beneath the retina. Blood, fluid, and proteins can seep out from these abnormal blood vessels and cause damage to the retina. Wet AMD progresses fast. If it is not treated at an earlier time, prolonging the eye’s ability to see may be too late.
Both dry and wet AMD can exist at the same time. Usually, wet AMD develops from dry AMD that is already in existence.
Signs and Symptoms of Age-Related Macular Degeneration
In general, age-related macular degeneration does not affect the vision greatly during its earlier stages. AMD can be asymptomatic. The onset of AMD can be felt when there are already changes in your eyesight. When these symptoms are already present, it means that the disease is already advancing to a much serious condition. These are the symptoms that you should look out for:
- Blurred central vision
- Central vision loss
- Dark or shadow spots in the vision
- Distorted lines or images
- Inability to distinguish colours of similar tones
Testing for Age-Related Macular Degeneration
Age-related macular degeneration may or may not exhibit symptoms. The best way to determine its existence is to have your eyes checked by the doctor. A couple of tests may be done to confirm if your eye is suffering from this condition. These are the tests that your doctor may ask you to take:
- Amsler Grid – The Amsler Grid is a screening tool used to check if there are slight changes affecting the eye’s normal function to see. This can also be done at home every day, so patients can monitor the condition of their eyes. In this test, a patient is asked to look at an Amsler grid chart. The chart is held at a level below the eye, similar to reading a book. To check for vision changes, cover one eye and focus on the dot located at the centre of the grid. Any changes in vision, such as wavy lines, blurry or dark spots, may indicate signs that AMD is present.
- Fundus Fluorescein and Indocyanine Angiogram (FFA and ICG) – These tests are done similarly. First, a fluorescent dye is injected into the patient’s arm. The dye then flows through the blood vessels and reaches the eye. Photo images of the eye are taken as the dye in the blood vessels passes through. The picture is then assessed to see if there are leaking blood vessels in the eye, which indicates the existence of wet AMD.
- Optical Coherence Tomography (OCT) – this test can be likened to the ultrasound as both uses “waves” to get photos of tissues in the body. The difference is that OCT uses light waves while ultrasound uses sound waves. To do the test, the eyes are dilated first. Then, the patient is asked to put their head on a chin rest and stay immobile while the light waves pass through and images of the eyes are taken. Once done, the images are examined to check whether AMD is present or not.
Treating Age-Related Macular Degeneration
There are several age-related macular degeneration treatments available. However, it is important to note that these treatments do not cure this eye condition. Despite advancements in medical technology and treatments, there is still no known cure for AMD. These treatments work to delay the continuous development of AMD, which results in vision loss. The response of the eye to the treatment will also depend on the severity of the AMD.
There is no available treatment for dry AMD, especially during its early stages. In general, doctors can only do as much as track its progression. A change in lifestyle will also be recommended for patients with dry AMD. Smokers will need to give up smoking as this is one of the factors that cause AMD. Patients will also be asked to eat healthy and nutritious foods. These recommendations neither cure nor prevent AMD, but they help in delaying its advancement to a much worse state.
Wet AMD has several treatments available:
- Laser therapy – Also known as laser photocoagulation, this treatment uses laser beams to destroy abnormal blood vessels that are present inside the retina. This treatment is risky as it also destroys healthy tissues around the abnormal blood vessels, resulting in further problems with vision.
- Drug therapy – This is the most common treatment used for wet AMD. Drug medications, such as anti-angiogenesis drugs and steroids, are injected into the eye and work to obstruct further growth of abnormal blood vessels into the retina. The eyes are numbed with anaesthesia before injecting the drug. Repeated administration of the drug is recommended over a period of 2 years to keep AMD under control.
- Photodynamic Therapy – A light-sensitive drug, verteporfin, is injected into the arm and travels throughout the body in the blood vessels. As verteporfin passes through the abnormal vessels beneath the macula, a light is probed into the eye to activate the drug and destroy these blood vessels that cause AMD.
Vision loss as a result of age-related macular degeneration can only be delayed with treatments and changes in a patient’s diet and lifestyle. The key to be able to prolong a patient’s vision is early detection and treatment of AMD. Do not wait for your AMD to reach an advanced state before getting tested for AMD. At the first sign of AMD, visit your eye doctor to discuss your condition and opportunity for treatment.