Age-related Macular Degeneration - What is it?
As its name suggests, age-related macular degeneration (ARMD) is degeneration of the center part of the retina (called the macula) that occurs as some individuals get older. The retina acts like the film in a camera, and good anatomical function of the retina is vital for good vision. Indeed, the most important part of the retina is the macula, as that is the part of the retina that provides our high-level central vision that we use for things such as reading, watching television, recognising faces, etc. If ARMD develops, the macula degenerates, and loses good function. As a result, the vision is very poor. ARMD is so common that it is the number one cause for visual impairment and resulting blind registrations in Western countries. The cause for ARMD is unknown, but factors that are known to play a part include age, genetics (more common in those that have a family history), smoking, and other environmental factors such as diet may also play a role. There are two main types of macular degeneration, commonly referred to as dry age-related macular degeneration and wet age-related macular degeneration.
Dry Age-related Macular Degeneration is the most common form of the disease, accounting for approximately 90% of cases. Dry ARMD develops more slowly than wet ARMD, but can progress to result in significant loss of central vision. There are no treatments as such for dry ARMD, though patients should be warned about the risk of developing distortion and sudden loss of central vision, as this can be the herald of newly developing wet ARMD. Magnifying lenses may offer some help in the patient managing activities of daily living.
Wet Age-Related Macular Degeneration only accounts for approximately 10% of cases, but the results can be devastating to the vision. It is usually as a result of "new" blood vessels growing under the retina. These blood vessels displace and damge the overlying retina, and in addition can bleed and scar resulting in loss of vision.