What is age-related macular degeneration (AMD)?

Macular degeneration is a condition that causes the centre of your vision to blur while the side or peripheral vision remains unaffected.

The macula is the central most part of the retina, the inner layer at the back of the eye responsible for detailed central vision. It is used for reading, driving and recognizing people’s faces. It is generally related to the aging process, and it is also commonly referred to as age-related macular degeneration (AMD). AMD is the leading cause of blindness in North America in adults over the age of 55.

What are symptoms of AMD?

In the earliest stages, macular degeneration is entirely symptom free but can be detected during routine eye exams.

The most common initial symptom is slightly blurred central vision when performing tasks that require seeing detail. Glasses cannot correct this blurred spot or sense that there is an obstruction in the way of clear vision.

Over time, the blurred area may increase in size and interfere with reading and recognizing faces. Other symptoms of AMD can cause straight lines to look wavy or distorted, and dark spots may blank out portions of the central vision. Patients experience no pain with AMD.

Are there different types of AMD?

There are two types of AMD: dry and wet.
Dry AMD

Dry AMD is the most common form. This is the milder form where there is a gradual degeneration of the central retinal tissues that make up the macula. Symptoms generally develop slowly over time.

Wet AMD

The wet form of MAD is a sudden leakage, or bleeding, from weak blood vessels under the macula. Symptoms of wet AMD progress rapidly. Wet AMD accounts for approximately 10% of all cases, but the dry form can develop into the wet form over time. Any sudden change in vision should be assessed by your Doctor of Optometry as soon as possible.

What causes AMD?

Factors linked to a higher risk of developing AMD include:

• Smoking
• High UV exposure (this may be sun or work-related)
• Advanced age
• Conditions: high blood pressure, arteriosclerosis, obesity and family history of AMD
• Diets high in fat, cholesterol, and sugar, and low in antioxidants
• Light eye colour
• Lack of physical activity

How can I prevent AMD?

You can reduce your risk of AMD through:

• Lifelong UV protection such as wearing UV-protective sunglasses if you spend a lot of time outdoors
• Good nutrition – reducing intake of fatty foods and increasing intake of antioxidants Antioxidants are found in green leafy vegetables, yellow and orange fruit, fish, and whole grains
• Not smoking
• Regular eye exams by a Doctor of Optometry are also important in the early detection of AMD

Early signs of AMD may be found during an eye examination even if no symptoms are noticed Your Doctor of Optometry can discuss ways to minimize the possibility of vision loss due to AMD.

Is there treatment for age-related macular degeneration?

• Dry AMD: boosting vitamins for your eyes and lifestyle modifications such as exercise, sunglasses to reduce UV radiation and smoking cessation 
• Wet AMD: many cases can be treated with medications injected into the eye to stop leaking blood vessels 
• Early detection and prompt intervention 
• Certain vitamins can also assist in slowing down the progression of AMD. 
• Regular eye examinations and counselling from your Doctor of Optometry will let you know when new treatments become available.

Is there help available?

Many patients with sight loss due to AMD can benefit from low vision aids. Your Doctor of Optometry can prescribe magnifying devices to enhance both distance and reading vision. These aids will not restore sight to normal levels, but they allow people to maximize their remaining vision. 

Your Doctor of Optometry may also train you to use an Amsler grid, which is a very sensitive tool that can assist in testing the progression of AMD at home. It is important to contact your Doctor of Optometry if you notice any changes in your central vision.