What is Age-related Macular Degeneration?
Age-related macular degeneration (ARMD) or Macular degeneration (AMD) is an eye disease related with aging which gradually affects central vision. However, it will not completely affect all your vision. Your vision will not go black but AMD can make you difficult to read, drive or perform daily routines which require sharp, fine central vision.
AMD is the leading cause of severe vision loss and blindness in people aged 60 and older. Thus, AMD is a growing problem particularly for elderly people. AMD, a source of significant visual disability, occurs with degeneration of the small central portion of the retina, known as the macula. The retina is the light-sensing nerve tissue at the back of the eye and is connected to the brain by the optic nerve.
The retina responsible for the sharp and clearly central vision needed for common daily tasks such as reading, driving, and sewing. In other words, AMD blurs the sharp vision for straight-ahead activities though you may still able to see shapes, light and movement.
Types of Age-related Macular Degeneration
Apart from the formation of drusen, Wet and Dry form are two main types of age-related macular degeneration. Most people with the dry form of AMD will not lose their central vision. However, dry AMD will lead to the wet AMD. Thus, it is very important for people with AMD to get their eyesight monitored carefully and consult with the eye doctor on a regular basis.
Drusen
The present of tiny yellow deposits (drusen) under the retina is early signs of AMD. This will appear visible to your eye specialists during an eye examination. The drusen is not the major cause of the disease but it means that your eye may be at risk for developing more severe AMD.
Dry AMD (Non-Neovascular)
It is an early stage of the disease, it may result from the aging and thinning of macular tissues, depositing of pigment in the macula, or a combination of the two processes. Dry AMD begins with one eye, but may later affect the other eye.
Dry AMD occurs when there is an accumulation of yellow deposits or debris (drunsen) from deteriorating tissue primarily in the area of the macula. The drunsen will not cause changes in vision, but when it grows in size and increase in number; it may lead to a dimming or distortion of vision. The dry AMD may also advance in the stage where the thinning of the light-sensitive layer of cells in the macular leading to tissue death (atrophy). People with atrophic form of macular degeneration may have blind spots in the centre of their vision. When this condition gets worse, people will lose central vision thoroughly.
Wet AMD (neovascular)
Approximately 10% of dry AMD will advance to a more damaging form of the eye disease known as wet AMD. The wet AMD occurs when abnormal blood vessels behind the retina starts to grow underneath the macular. This condition is called choroidal neovascularization (CNV). These blood vessels tend to be very fragile and always leak blood and fluid into the retina, and subsequently causing permanent damage to light-sensitive retinal cells, which die off and create blind spots in central vision. Thus, people with wet AMD can loss their vision rapidly. Also, wet AMD causes distortion of vision that makes straight lines look wavy, as well as blind spots and loss of central vision.
What are the Symptoms of Macular Degeneration?
Both dry and wet AMD cause no pain at all. In more cases, AMD progresses extremely slow that people were unaware or notice little change in their vision. In the initial stage, AMD has no significant symptoms until it advances or affects both eyes. Distortion of straight lines is a first sign of macular degeneration. This condition will then progress to a gradual loss of central vision.
Common symptoms include straight lines, such as sentences on a page, telephone poles, and the sides of buildings start to appear distorted or wavy. The centre of vision appears dark, blur or white. A dark or empty area (blind spot) also appears in the centre of vision. Color perception may change or diminish. People with AMD suffer with blurry or fuzzy vision, and sometimes they find difficulty in recognizing familiar faces.
As for dry AMD, the most common symptom is slightly blurred central vision, which looks like a blind spot right in the middle of your vision. Over times, as less of the macular can function well, people will see objects in front of them less clear, such as faces, shapes or words in a book. If the loss of light-sensitive cells becomes greatly, people may also see a small, but growing blind spot in the centre of their field of vision.
