Macular Degeneration

What is macular degeneration?

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. Macular degeneration is a condition that causes the centre of your vision to blur while the side or peripheral vision remains unaffected. It is generally related to the aging process, and is also commonly referred to as age-related macular degeneration (AMD). It is the leading cause of blindness in North America in adults over the age of 55.

What are the symptoms of AMD?

In the earliest stages, macular degeneration is entirely symptom free but can be detected during annual eye health examinations. The most common initial symptom is slightly blurred central vision when performing tasks that require seeing detail. Glasses cannot correct this blurred spot. 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 forms?

There are two types of AMD: dry and wet. The most common is the dry form. This is the milder form where there is a gradual degeneration of the central retinal tissues that make up the macula and symptoms generally develop slowly over time. The wet form is a sudden leakage, or bleeding, from weak blood vessels under the macula and symptoms progress rapidly. Wet AMD accounts for approximately 10 per cent of all cases, but the dry form can develop into the wet form over time.

Who is at risk of developing AMD?

The risk of developing AMD increases with age. High-risk groups include smokers and people who have had extensive UV exposure. AMD is also associated with conditions such as high blood pressure, arteriosclerosis, and those with a family history of AMD.

How can I prevent AMD?

Lifelong UV protection and good nutrition are believed to play a key role in preventing AMD. Living a healthy lifestyle by keeping your blood pressure down, reducing your intake of fatty foods and not smoking are all recommended. A diet high in antioxidants such as beta-carotene (a form of vitamin A), vitamins C and E, zinc, lutein, zeaxanthin, selenium and omega 3 fatty acids may help prevent AMD. Most of these antioxidants are found in fruits and leafy green vegetables.

Annual eye examinations by your optometrist 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 optometrist can discuss ways to minimize the possibility of vision loss due to AMD.

Is there treatment for macular degeneration?

Currently, dry AMD is treated with ocular vitamin supplementation and lifestyle modifications such as exercise, sunglasses to reduce UV radiation and smoking cessation. Many cases of wet AMD can be treated with medications injected into the eye to stop leaking blood vessels. Early detection and prompt intervention are crucial to addressing wet AMD.

Certain vitamins can also assist in slowing down the progression of AMD. The use of vitamins will not reverse any vision loss that has already occurred, nor will it stop the progression of AMD completely. Regular eye examinations and counseling from your optometrist 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 optometrist 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 optometrist may also train you to use an Amsler grid, which is a tool that can assist in testing the progression of AMD at home. It is important to contact your optometrist if you notice any changes in your central vision.