The macula is a small but important area in the retina at the back of the eye that receives light for vision. When the macula is affected by disease, your central vision will be affected with blurring, patches, dark areas or distortion.
In macular degeneration there is a deterioration or breakdown of the macula, usually caused by aging. Central vision is affected but vision at the side, also called peripheral vision, is spared. A person with macular degeneration may be able to see the outline of a patient’s face, but may not be able to make out details of the facial features like the nose and mouth.
Fortunately, macular degeneration usually does not result in total blindness, even in the more advanced cases. Patients continue to have useful peripheral vision and are often able to perform most activities of daily living and take care of themselves.
Many older people develop macular degeneration as part of the body’s aging process. Age-related macular degeneration (AMD) is one of the commonest forms of macular degeneration. How and why it develops with increasing age is not fully understood.
There are two types of AMD:
This is the commoner form of AMD. It is caused by aging and thinning of the tissues of the macula. Visual loss is usually gradual.
Drusen are whitish-yellow deposits under the retina. They are a common feature of macular degeneration (both the “dry” and “wet” forms). Drusen alone usually do not cause visual loss, but may do so if they increase in size or number
“Wet” macular degeneration is caused by “leaky” blood vessels in the retina. These blood vessels are abnormal and may leak blood or fluids into the retina, causing loss of vision. The visual loss in this form of macular degeneration can be profound, and sometimes occurs suddenly.
In its early stages, the condition may be hardly noticeable, and there may be no visual symptoms.
In its more advanced stages, the following may occur:
In early cases where vision is not affected, no treatment is required. Regular self-monitoring with an Amsler grid chart is all that is required.
In more advanced cases, these are the treatment options:
Certain types of “wet” AMD can be treated with special lasers that use a focused beam of light to slow or stop leaking blood vessels that damage the macula.
This uses a combination of a special drug and laser treatment to slow or stop leaking blood vessels.
The abnormal blood vessels in “wet” macular degeneration leak because of a chemical called VEGF that is present in large quantities in AMD. The drugs that are used to block the action of VEGF are called “anti-VEGF”. These drugs are injected into the vitreous humor of the eye, and the procedure is referred to as an “intravitreal injection”. These anti-VEGF intravitreal injections reduce the leakage of the abnormal vessels, resulting in stabilization or improvement in vision.