What is the Difference Between Wet and Dry Macular Degeneration?

Macular degeneration, also known as age-related macular degeneration or AMD, is a common cause of vision loss for people aged 50 and older. When discussing macular degeneration, it is important to understand the difference between the two types: wet and dry macular degeneration. Each type of the condition affects vision in different ways and requires unique approaches to treatment. Knowing the differences can help patients and medical providers make informed decisions and potentially mitigate the progression of the disease.

What is Macular Degeneration?

To understand what AMD is, let’s start by looking at the structure of the eye. It helps to think of the eye like a camera. When light enters the eye, it first passes through the cornea, which acts as the lens at the front of the eye. Next, it moves through the natural lens, located just behind the colored iris and the black pupil. From there, the light travels through the jelly-like vitreous inside the eye and reaches the retina at the back. The macula, a highly specialized part of the retina, is located at the center of the back of the eye.

Macular degeneration affects this critical area, damaging the retina and making it harder to see fine details, read, recognize faces, or distinguish colors.

What Are the Symptoms of Macular Degeneration, and What Does Someone See?

Often an initial symptom of many illnesses is the presence of pain, which may indicate there is a problem. Macular degeneration, however, is not associated with pain, which can make its presence go overlooked at first. Some of the early symptoms include:

• Blurred vision
• Difficulty reading small print
• Changes in color vision
• Distorted vision, in which straight lines like door frames may appear wavy or bent

As macular degeneration advances, people begin to experience a loss of central vision. This means that the object of their focus is missing. For instance, if you look at someone’s face, you might only see the ears and shoulders, but not the face itself. Or if you look at a clock, you may see the numbers, but not the hands.

It’s important to note that having some of the above symptoms does not necessarily mean you have macular degeneration; other eye conditions, like cataracts or refractive error, may cause similar symptoms, so it’s important to get a proper evaluation from your eye doctor to determine the precise cause of your symptoms.

What is Dry Macular Degeneration?

To understand the difference between wet and dry macular degeneration, the first thing to know is that you can’t develop wet macular degeneration without first having dry macular degeneration. Dry, or atrophic, macular degeneration is the more common form, accounting for nearly 80% of AMD cases. It occurs when parts of the macula deteriorate due to the accumulation of protein deposits called drusen under the retina. These drusen interfere with the macula’s ability to function correctly. In the majority of cases, AMD does not advance beyond the presence of drusen and some color changes; however, more advanced stages lead to geographic atrophy, in which larger swaths of the retina are affected.

What is Wet Macular Degeneration?

What happens with wet, or exudative, macular degeneration is that your body attempts to “fix” the dry macular degeneration problem in the macula by creating new blood vessels to supply more oxygen and nutrients. While this response might heal other parts of the body, it doesn’t work well in the eye. Instead, these new blood vessels often leak fluid, or even blood, which leads to the name “wet macular degeneration.” Unfortunately, this leakage damages your vision faster than dry macular degeneration does.

Risk Factors of Macular Degeneration

Age-related macular degeneration can be caused by genetic, environmental, or lifestyle factors. When we talk about the difference between wet and dry macular degeneration, the risk factors for both are generally the same and include:

• Age: Age is the biggest risk factor; the condition primarily affects individuals over the age of 60.
• Family history: If you have had a family member with macular degeneration, you have a greater chance of developing it.
• Ethnicity: AMD is more common in white people.
• Smoking: Smoking reduces the amount of oxygen reaching parts of your body, including your eyes, which leads to increased retinal damage over time.
• Obesity: Carrying excess weight can increase inflammation that contributes to AMD.
• High blood pressure: Like smoking, hypertension reduces the oxygen to your eyes.
• Poor diet: A low-quality diet deprives eyes of the nutrients needed to maintain healthy vision.

Again, before a person can develop wet macular degeneration, they must have dry macular degeneration first. Having more risk factors is not a guarantee that dry macular degeneration will progress to wet macular degeneration, but it does increase the likelihood.

Diagnosis and Treatment

The diagnosis of both types of AMD begins with a comprehensive eye exam, which may include a visual field test, an Amsler grid test, a fluorescein angiography, or optical coherence tomography (OCT) imaging test. These diagnostics will indicate the presence of macular degeneration and the stage it is in.

Currently there is no cure for age-related macular degeneration, but there are treatments and lifestyle changes that will slow its progression. For dry AMD, eating a diet high in antioxidants, quitting smoking, managing high blood pressure, and if recommended by your doctor, taking vitamin supplements containing lutein or zeaxanthin can benefit retinal health.

For wet AMD, injectable medications exist that can stop the growth of excess blood vessels and reduce leakage. Other treatments may include laser therapy and photodynamic therapy.

Further, a low vision doctor assists by evaluating your remaining vision and recommending specialized glasses, magnifiers, or other visual aids that can help restore functional vision to meet your lifestyle goals.

Next Steps

If you suffer from macular degeneration and are interested in learning more about the aids available to boost functional vision and get back to your daily activities, seek out a low vision doctor near you. If you are in the Bloomington, Clarksville, or Evansville, Indiana areas, Midwest Low Vision can help you take control of your macular degeneration and regain quality of life. Give us a call at 877-577-2040 or contact us on our website.