This blog is from research that Linda has been conducting for her Doctorate in Occupational Therapy. Linda wrote the following blog based on her research on AMD – Age Related Macular Degeneration.
Age-related macular degeneration (AMD) is a disease that can be part of aging. AMD affects how sharp vision is and it specifically affects central vision. Central vision is important for activities such as reading and driving, where it is important to see an object clearly.
AMD affects a structure known as the macula in the eye as shown in the figure of a cross section of an eye below. The macula allows us to see fine detail.
In some cases, AMD advances slowly. In this case, an individual may not even notice change to their vision. In other people, the disease occurs quickly and leads to vision loss in both eyes.
What is Dry AMD?
There are two forms of AMD – wet and dry. Wet AMD is responsible for severe vision loss that occurs quickly. We are going to focus on dry AMD. Dry AMD occurs when light -sensitive cells in the eye slowly break down. Over time, central vision blurs in the affected eye. You can have trouble recognizing faces or reading.
Let’s look at Dry AMD in a bit more detail.
Under the retina, yellow deposits can develop known as drusen. Drusen are found in people over the age of 60. If you have drusen, it does not mean you have AMD. Scientists are even unsure how drusen are associated with AMD, but if they increase in size or number it raises the risk of developing dry AMD or wet AMD. There are three stages of Dry AMD.
Three Stages of Dry AMD:
1) Early AMD – no symptoms or loss of vision, but several small drusen or a few medium sized drusen are detected.
2) Intermediate AMD – many medium sized drusen or one or more large drusen are detected. In some cases, individuals see a blurred spot in the center of their vision. Individuals may need more light for reading or other tasks.
3) Advanced Dry AMD – individuals not only have drusen, but they have a breakdown of light sensitive cells and tissue supporting the central retinal area. Breakdown of this area can result in a blurred spot in the center of vision. If left untreated, it can get bigger and darker. You can have trouble recognizing faces, as shown in the next figure (CNIB, 2006).
Treatment for AMD:
At the current time, there is no cure for AMD, but there is a treatment to delay and possibly prevent intermediate AMD from moving to the advanced dry AMD.
High dose mixtures of antioxidants and zinc can significantly reduce the risk of advanced dry AMD which is associated with vision loss. See your physician.
Remember, it is important to have your vision checked regularly at least every year!
CNIB website: http://www.cnib.ca/en/your-eyes/eye-conditions/amd/Default.aspx
National Eye Institute: http://www.nei.nih.gov/