Wet macular degeneration

Overview

Wet macular degeneration is a long-lasting eye disorder that causes blurred vision or a blind spot in the central vision. It's usually caused by blood vessels that leak fluid or blood into the macula (MAK-u-luh). The macula is the part of the retina that gives the eye clear vision in the direct line of sight.

Wet macular degeneration is one of two types of age-related macular degeneration. The other type, dry macular degeneration, is more common and less severe. The wet type always begins as the dry type.

Early detection and treatment of wet macular degeneration may help reduce vision loss. In some instances, early treatment may recover vision.

Symptoms

Wet macular degeneration symptoms usually appear suddenly and worsen quickly. They may include:

• Visual distortions, such as straight lines seeming bent.
• Reduced central vision in one or both eyes.
• The need for brighter light when reading or doing close-up work.
• Difficulty adjusting to low light levels, such as when entering a dimly lit restaurant or theater.
• Increased blurriness of printed words.
• Difficulty recognizing faces.
• A well-defined blurry spot or blind spot in the field of vision.

Macular degeneration doesn't affect side vision, so it doesn't cause total blindness.

When to see a doctor

See your eye doctor if:

• You notice changes in your central vision.
• You lose the ability to see fine detail.

These changes may be the first indication of macular degeneration, particularly if you're older than age 60.

Causes

No one knows the exact cause of wet macular degeneration, but it develops in people who have dry macular degeneration. Of all people with age-related macular degeneration, about 20% have the wet form.

Wet macular degeneration can develop in different ways:

• Vision loss caused by irregular blood vessel growth. Sometimes irregular new blood vessels grow from the choroid under and into the macula. This is known as choroidal neovascularization. The choroid is the layer of blood vessels between the retina and the outer, firm coat of the eye, called the sclera. These blood vessels may leak fluid or blood, affecting the retina's function.
• Vision loss caused by fluid buildup in the back of the eye. When fluid leaks from the choroid, it can collect between the thin cell layer called the retinal pigment epithelium and the retina or within the layers of the retina. This may cause irregularities in the macula layers, resulting in vision loss or distortion.

Risk factors

Factors that may increase your risk of macular degeneration include:

• Age. This disease is most common in people over 55.
• Family history and genetics. This disease has a genetic component. Researchers have identified several genes linked to the condition.
• Race. Macular degeneration is more common in white people.
• Smoking. Smoking cigarettes or being regularly exposed to tobacco smoke greatly increases your risk of macular degeneration.
• Obesity. Research indicates that being obese increases the chance that early or intermediate macular degeneration will progress to a more severe form of the disease.
• Cardiovascular disease. If you have diseases that affect your heart and blood vessels, you may be at higher risk of macular degeneration.

Complications

People whose wet macular degeneration has progressed to central vision loss have a higher risk of depression and social isolation. With profound loss of vision, people may see visual hallucinations. This condition is known as Charles Bonnet syndrome.

Prevention

It's important to have routine eye exams to identify early signs of macular degeneration. The following measures may help reduce your risk of developing wet macular degeneration:

• Manage all other medical conditions. For example, if you have cardiovascular disease or high blood pressure, take your medicine and follow your health care provider's instructions for controlling the condition.
• Don't smoke. Smokers are more likely to develop macular degeneration than nonsmokers. Ask your provider for help stopping smoking.
• Maintain a healthy weight and exercise regularly. If you need to lose weight, reduce the number of calories you eat and increase the amount of exercise you get each day.
• Choose a diet rich in fruits and vegetables. These foods contain antioxidant vitamins that reduce your risk of developing macular degeneration.
• Include fish in your diet. Omega-3 fatty acids, which are found in fish, may reduce the risk of macular degeneration. Nuts such as walnuts also contain omega-3 fatty acids.