Age-related macular degeneration: Early detection and timely treatment may help preserve vision – . Health Blog

Age-related macular degeneration (ARMD) is the leading cause of blindness in adults over the age of 60. As the name suggests, the disease mainly affects the macula, the region of the retina responsible for central vision. A person whose macula has retinal disease may develop difficulty with tasks such as reading and driving, but may maintain good peripheral vision.

If you have ARMD, understanding the signs and symptoms, proper monitoring, early detection of disease progression, and timely treatment are keys to maintaining eyesight.

Stages of age-related macular degeneration

ARMD can be classified as early, moderate, or advanced depending on physical changes an ophthalmologist reveals during an eye exam. Early ARMD is characterized by the presence of small yellow deposits known as drusen in the layer behind the retina. Drusen can be found in healthy eyes as people age. However, when they become numerous, a diagnosis of ARMD can be made. People with early ARMD may not experience visual symptoms and are likely to have good visual function when measured using standard methods such as an eye chart.

When the number and size of drusen reach a certain threshold, ARMD is classified as moderate, which puts them at greater risk of advanced ARMD and vision loss. In patients with moderate ARMD, early symptoms such as distortion of central vision or slight loss of visual acuity may occur, although this is not always the case.

A term for advanced ARMD is given when patients develop either a degenerative loss of photoreceptors (light-sensitive cells in the retina) called atrophy or abnormal blood vessel growth called choroidal neovascularization (CNV).

There are two main types of advanced ARMD: exudative (wet) ARMD and non-exudative (dry). The presence of CNV gives a name for wet ARMD. All other forms of ARMD, including early, intermediate, and atrophy, are considered dry ARMD. Almost every case of wet ARMD starts out as dry ARMD.

When advanced ARMD affects the fovea, which is the photoreceptor-rich center of the macula, patients can experience severe vision loss. Atrophy usually develops slowly over time, with loss of vision as it encroaches on the fovea. The effects of CNV, including the buildup of fluid or blood under or within the retina, can come on more quickly and lead to sudden deterioration in vision.

Preservation of vision in people with macular degeneration

The age-related eye disease clinical studies (AREDS and AREDS2) found that taking antioxidants, lutein, and zeaxanthin at the doses studied reduced the risk of middle to advanced-stage ARMD progressing by about 25%, and thus the chances of vision maintenance increased .

In people who develop advanced ARMD, the availability of treatment options depends on whether they have the dry or wet form of the condition. There is no FDA approved treatment for advanced dry ARMD. However, several therapies are being explored that may one day slow or potentially reverse the changes that affect vision.

Conversely, wet ARMD has several FDA-cleared and unapproved agents that have been shown to inhibit and reverse the effects of CNV on the macula. The current standard of care is the injection of anti-vascular endothelial growth factor (anti-VEGF) drugs into the vitreous cavity (the gel-filled space that makes up most of the eyeball). Anti-VEGF drugs work by stopping abnormal new blood vessels from growing. There are also several promising treatments for wet ARMD in the pipeline, including longer-lasting anti-VEGF drugs, combination drugs, surgically implanted drug reservoirs, and gene therapy. There is also hope for eye drops or oral medications, although these therapies have a longer time horizon.

Reducing the risk of progression and early detection of advanced ARMD are vital

If you have ARMD, the best way to maintain eyesight is to reduce the risk of moving to more advanced ARMD and to identify the treatable moist form early on. To begin with, quitting smoking and eating a healthy diet can reduce the risk of progression to advanced ARMD and prevent associated vision loss. Your eye doctor will recommend AREDS2 vitamins, available over the counter without a prescription, to reduce the risk of further progression if you have been diagnosed with intermediate ARMD. He or she will also regularly check for signs of the disease getting worse.

Be aware of symptoms of progressive macular degeneration, including blurred or distorted central vision. At the direction of your ophthalmologist, monitor your vision at home with an Amsler grid (a grid of horizontal and vertical lines to monitor the central field of vision) or other home monitoring device. More advanced home surveillance systems, including retinal scanning devices, are on the horizon. They can help identify wet ARMD so that it can be treated before there is permanent damage to the retina.

Current therapies can control the disease and maintain vision for years or more. Early detection is therefore key. Additionally, regular follow-up exams with an ophthalmologist remain important as he or she looks for signs of the disease's progression that you may not be able to see. Your ophthalmologist will also be best aware of new and emerging treatments in the rapidly evolving landscape of ARMD therapy.