For information and videos on the retina and macula, click here
What is age-related macular degeneration?
Age-Related Macular Degeneration (AMD) is a painless disease that damages the central portion of the retina, the macula. The disease causes blurring, loss of central vision, and greatly affects quality of life. The disease is very common in Canada and the US. It is the leading cause of blindness in people over the age of 60 in Canada. While the disease causes loss of central vision, it does NOT cause blindness.
What are the types of age-related macular degeneration?
There are two types of AMD; dry AMD and wet AMD.
Dry AMD is the most common type (80% of cases). This occurs because with time the blood flow underneath the retina slows down and is not able to wash away the retinal waste products. These waste products are toxic to retinal cells leading to their death and a blurring of vision.
This is dry macular degeneration. The whitish-yellow spots seen at the macula are collections of waste products that are toxic to the retinal cells.
Wet AMD occurs when new blood vessels grow in between the collections of waste products mentioned above. These blood vessels are not good blood vessels and tend to break down and bleed within the retina. This bleeding results in quick and serious damage to the retinal cells. Patients with wet AMD start to see images being distorted and can lose their vision very quickly.
This is wet macular degeneration showing bleeding and scaring at the macula.
What are the risks of macular degeneration?
• Age: nearly 30% of those over 75 have some evidence of AMD • Smoking: smokers are three times as likely to develop AMD than non-smokers • Obesity: obesity may contribute to the advancement of AMD • Race: lightly-pigmented people are more likely to develop AMD • Family: people with a family history are more likely to develop AMD
How is macular degeneration diagnosed?
Macular degeneration is diagnosed by a full eye exam that includes vision tests as well as direct examination of the retina. Direct examination of the retina can be done with ophthalmoscopy, fluorescein angiography (a dye is used to search for hidden blood vessels that could result in wet AMD) or OCT (optical coherence tomography, which generates a computer image of the retina).
How is macular degeneration treated?
Treatment of AMD is different for the dry and wet type.
• For dry AMD, treatment is not required in the early stages and there is only a small chance the disease will advance. If it progresses, studies have shown that vitamins can help prevent further damage. Unfortunately, no treatment is available if the disease progresses to its advanced stage.
• For wet AMD, there are laser and drug treatments available. Laser therapy directly targets and destroys the blood vessels surrounding the macula while photodynamic therapy (PDK) targets a special injected dye to destroy the vessels in areas more central to vision.
In the past few years, drug treatments for wet AMD have completely revolutionized treatment of the disease. Rather than simply slowing the progression of the disease, some drugs have actually been able to restore vision. Currently, these drugs must be injected into the eye, as shown below.
Diagram showing the intravitreal injection of a drug to treat wet AMD. Avastin and Lucentis are the most common drugs used for this purpose.
What is Avastin?
Avastin is one of the types of drugs used to treat wet AMD. Unfortunately, Avastin is not available in eye drops, and must be injected into the eye, as shown above. However, the increase in vision many patients experience with the drug makes the injection well worth the inconvenience. For an FAQ document about Avastin injections at our department, click here.
WWW.MACDEGEN.COM is a website designed by Dr. Sanjay Sharma, a retina specialist from Queen’s University. Patients can diagnose and track the disease, and read about research and new treatments for the disease. As well, there are many videos and sound clips on the website to educate patients and their families. The website now reaches tens of thousands of patients and doctors worldwide; joining WWW.MACDEGEN.COM is free.
