We often think of healthy lifestyles to prevent cardiovascular disease, osteoporosis or cancer. But did you know that healthy lifestyles can also protect your vision? As you age, you’re prone to develop an eye condition called age-related macular degeneration or AMD. AMD is now the leading cause of vision loss in people aged 50 years and older.

What is AMD?

The retina is the tissue located at the back of your eyeball. When you age, the central spot in your retina, known as the macula, can weaken and lose its function. Your macula is made up of millions of light-sensitive cells that allow you to see sharp and clear images right in front of you. A healthy macula in each eye allows you to read, drive and recognize colours and faces. In AMD, cells in the macula breakdown and destroy central vision. AMD does not affect peripheral vision.

As you age, you can also develop small white-yellowish deposits under your retina. They can pop up in your 30s, 40s or later on. These deposits are called drusen. Eye specialists can detect drusen. Most people with AMD have an increase in the size and number of drusen. However, not everyone who has AMD has drusen. Scientists are unclear as to whether drusen alone increases your risk of developing late stage AMD.

The stages of AMD

AMD has three stages – early, intermediate and advanced – during any of which, AMD may occur in one or both eyes. In the early stage, people have small drusen or a few medium-size drusen and there is no vision loss.

In the intermediate stage, there’s either a larger number of medium-size drusen or one or more large drusen. The retina can also have pigmental changes. Central vision may be blurred and extra light for reading may be needed, though most people report no symptoms. In the late stage, there is central vision loss and damage to the macula.

There are 2 types of late AMD:

1. Dry AMD: a gradual breakdown of the cells in the macula causes blurring and blank spots in one’s central field of vision. Most people with vision loss have dry AMD. In advanced cases, recognizing faces and printed words can be difficult. People with dry AMD are at risk for developing wet AMD.

2. Wet AMD: abnormal blood vessels grow under the retina and leak blood and fluid into the macula, causing damage. Central vision loss is rapid and severe. Images are blurry and lines appear crooked.

Treatment

There is no treatment for the early AMD stage. However, regular eye exams are necessary to determine if the condition is advancing. For the intermediate and late stages, there is no cure but there are treatments that can slow down or stop the disease from progressing.

The National Eye Institute (NEI) recommends the following vitamin formula to slow down vision loss for people with intermediate AMD or late AMD in one eye:

• 500 milligrams of vitamin C
• 400 International Units (IU) of vitamin E
• 15 milligrams of beta-carotene (up to 25,000 IU of vitamin A)
• 80 milligrams of zinc (zinc oxide)
• 2 milligrams of copper (cupric oxide)

Talk to your doctor before starting vitamins. Patients at risk for lung cancer (e.g. current or past smokers) should not take beta-carotene and may need alternative vitamins.

For wet AMD, anti-VEGF eye injections, thermal laser surgery or photodynamic therapy are treatments and not cures. They can slow or prevent further vision loss. A telescopic lens implant in one eye may improve vision in patients with advanced macular degeneration in both eyes.

Risk factors

The cause of AMD is not known though some risk factors are linked to the disease. The greatest risk factor is age. Adults over the age of 75 have a 30% risk of AMD. Women are generally at high risk because they live longer than men. Other factors are smoking, prolonged exposure to UV sunlight and/or blue light from computer screens and TV, a family history of AMD, obesity, white race, light-coloured eyes, high blood pressure, cardiovascular disease and elevated cholesterol.

Prevention

Genetics is only part of the total AMD risk. Your lifestyle plays a heavy role in reducing your risk of developing AMD or slowing down the disease if you already have it. One way to view AMD prevention is to take care of your eyes the same way you take care of your heart. Eating a healthy diet, not smoking and exercising regularly will keep your circulation, blood pressure, cholesterol and weight within normal levels. The following measures can help prevent vision loss:

• Avoid or quit smoking.
• Include a variety of colourful fruits and vegetables in your diet. Green leafy vegetables, such as kale, broccoli and spinach, are rich in antioxidants, lutein and zeaxanthin.
• Eat foods that are high in omega-3 such as fish, kidney beans, nuts/walnuts, squash, fish oil or flaxseed oil.
• Include more movement in your life and exercise regularly.
• Wear hats and protection sunglasses (labeled UV 400) when outdoors. Light-pigmented eyes give less protection against UV light.
• Take regular breaks when working on computers and tablets and avoid evening computer work as much as possible.
• Install the f.flux program on your computer. This program can reduce your exposure to blue light emitted from your computer.
• Consider wearing blue-blocking glasses or amber goggles to reduce blue light exposure.
• If you have a health condition, such as diabetes or cardiovascular disease, keep up with the medical management of your condition.
• See your eye specialist for regular eye exams. Report any changes in your central vision.

When to see an eye doctor

According to the Mayo Clinic, see your eye doctor if you notice these changes:

• The need for brighter light when reading or doing close work
• Increasing difficulty adapting to low light levels (e.g.: entering a dimly lit restaurant)
• Increasing blurriness of printed words
• A decrease in the intensity or brightness of colors
• Difficulty recognizing faces
• A gradual increase in the haziness of your central or overall vision
• Crooked central vision
• A blurred or blind spot in the center of your field of vision
• Hallucinations of shapes or people, in case of advanced macular degeneration

Living with AMD may bring difficult challenges in your life. However, adjustments can be made and you can live a relatively normal life. The use of magnifying eyewear and technological devices can help you cope. With people living longer, there’s a need for more sophisticated ways to detect, treat and prevent AMD. Currently, scientific research is looking at transplanting healthy cells into diseased retina.

First photo credit: Andreia

Second and third photo credits: National Eye Institute