Macular Degeneration

Macular degeneration (or age-related macular degeneration, abbreviated AMD) is the leading cause of vision loss in the western world. The disease affects the retina, the light-sensitive layer of tissue at the back of the eye. Specifically, AMD affects the central part of the retina called the macula and this is the portion of your eye that is used when engaging in visual activities that require the finest visual acuity such as reading and driving. Macular degeneration occurs in either a dry (atrophic) or wet (exudative) form. In either case, the disease only affects the central vision, typically near the macula, and rarely causes total vision loss.

Normal		Macular Degeneration

The majority of patients (over 80% of AMD cases) have the dry or atrophic type of macular degeneration. In this form of the disease, the slow deterioration of the retina is coincidental with the formation of small yellow deposits, known as drusen, in the macular region. This accumulation of drusen leads to a thinning of the macular tissues, causing distortions in vision that initially appear as wavelike. The eventual amount of central vision loss is directly related to the location and amount of retinal thinning caused by the drusen.

The exudative, or wet form of the disease, is far less common (about 20% of AMD cases), but it is more aggressive and threatening to one's vision. In the wet type of macular degeneration, abnormal blood vessels grow under the retina and macula through a process called neovascularization. These new blood vessels may bleed and leak fluid, thereby causing the macula to bulge or lift up, distorting or destroying central vision. In these circumstances, vision loss may be rapid and severe.

In terms of treatments for AMD, there are a number of anti-VEGF (vascular endothelial growth factor) injectable drugs available for the less common wet form of AMD as well as some surgically implantable solutions, but in some cases, the outcome does not meet the patient's expectations and they are still unable to perform activities of daily living successfully. And with regard to the dry form, no drug treatments are on the market as of yet, although extensive research is ongoing.

Regardless of the type of AMD, low vision devices are excellent stand-alone or adjunct solutions that are proven to help people with this eye disease see better and maximize their remaining vision so they can remain independent and active and enjoy a higher quality of life.