Macular Degeneration:

What is Macular Degeneration?

Age-related macular degeneration (AMD) is a condition where the light-sensing cells at the back of the eye (our photoreceptors, called rods and cones) become sick and are slowly destroyed. This results in a loss of vision straight ahead; it degrades our ability to see details.  Because AMD only affects a small portion of the retina, peripheral vision is usually unaffected, as shown in the photo below.  This condition happens as we age (it’s most prevalent over age 55), but early signs of macular degeneration can be seen in younger people too!  This is one reason why our doctors recommend a comprehensive eye exam each year for all adults. 

AMD consists of two main forms: dry and wet

Dry macular degeneration

This most common form is defined as reduced function or death of the light-sensing cells that provide our central vision.  Mild forms often starts with subtle changes in vision when tissue begins functioning poorly. However, it can progress to more advanced vision loss or complete central blindness over time.  All forms of AMD start in this way.

What does dry or wet have to do with the inside of the eye: isn’t the eye filled with fluid inside?

Eye doctors are tend to use simple terms when describing things: Leaky blood vessels = wet. No leaky blood vessels = dry

Yes, the eye is filled with a fluid call the vitreous, a gel like structure that supports the eye and keeps it from shriveling up like a raisin, but that’s not what is meant by wet or dry with AMD.

The term ‘wet’ refers to the formation of new blood vessels in tissue where they don’t belong. These new blood vessels are often very leaky and cause a lot of collateral damage to the surrounding tissue.

Because they are leaky, we call this disease the ‘wet’ version of AMD. No new blood vessels and you have the ‘dry’ form.

Stages: mild, moderate and severe

Early signs of the ‘dry’ form are accumulation of small drusen around the macula; drusen is cellular waste building up next to the photoreceptors. This happens in the mild stage.  This of these as individual areas of disrupted tissue; each is well defined and separated from nearby drusen. (If AMD was salsa, think of mild stage like pico de gallo: the onions and peppers (drusen) can be easily identified from the tomatoes (retina in this analogy).)

As the disease progresses to the moderate stage (image from above), larger and more numerous drusen are visible. The borders of drusen start to blur together; there can be changes in the appearance of the macular pigment, called “pigment mottling”.  This retinal tissue is now noticeably different from healthy retina. (If AMD was salsa, think of moderate stage like classic chunky salsa: the onions and peppers can be picked out but they are starting to blend with the tomatoes and are harder to distinguish individual items from each other.)

The most severe stage of the “dry” form is called geographic atrophy – by this stage, there is a large area in the middle of your retina where all of the photoreceptors and some of the supporting retinal layers have died off completely, leaving a large and permanent hole in your central/detailed vision. Once tissue is lost (dies), currently, there is no way to heal it. (If AMD was salsa, think of geographic atrophy like an empty salsa bowl: there might be some areas where salsa residue remains, but there isn’t much left .)

What macular degeneration can look like:

The right image is mild drusen. It’s hard to see, but notice the slightly yellow spots scattered where the arrow is pointing. The left image shows geographic atrophy, the area inside the pink outline is dead and you can see the supporting blood layer instead of retina. Notice the left image also has lots of drusen in the area outside the atrophy, showing that tissue isn’t very healthy either.

Wet macular degeneration

This is the most advanced form of the disease. This occurs when damaged retinal cells send signals that it needs more nutrients; new blood vessels begin to form to help support the damage tissue. The problem with these vessels, as mentioned above: they are leaky, causing tissue to swell, and can rapidly advance to form a disc-like scar (large area of complete vision loss). Roughly 20% of people with dry macular degeneration will eventually develop the wet form.  This usually results in a much greater loss of vision than the dry type. There are ways to halt the vessel formation, but once a scar forms, the tissue is permanently damaged.

What are the main causes of AMD?

Numerous factors are known to contribute to macular degeneration – especially UV exposure (sunlight!).  Things that put you at higher risk of developing macular degeneration include:

• a close family member who has had macular degeneration
• having lighter skin tone (the eye is more easily damaged from UV, just like skin)
• significant sun exposure/not wearing sunglasses
• smoking
• eating a poor diet (not getting enough carotenoids like lutein and zeaxanthin from food)
• poor cardiovascular health (uncontrolled or poorly controlled diabetes or high blood pressure)
• sedentary life style (correlates to poor cardiovascular health)

How do I know if I have age-related Macular Degeneration?

Patients with macular degeneration sometimes notice:

• Blurred vision, since it affect central vision, it can be very noticeable as it tracks everywhere you’re trying to look
• Missing letters when looking at a page of text
• Frequently losing your place when reading (challenging to follow a line of text on a page)
• Straight lines appearing wavy (door frames, lines on paper, etc)
• Trouble making out or recognizing faces

If you are experiencing any of these – make an appointment to see one of our doctors, and then read on to learn more about AMD and how we diagnose and manage it!

What to expect at the doctor visit/ how is it diagnosed?

At your visit, one of our doctors will test your vision (with a refraction) to determine how well you’re seeing in each eye.  Next, they will dilate your eyes (expanding your pupils with eye drops) to take a good look at your retina – even some mild forms of AMD can be found with just a small magnifying lens!  Your doctor may also take photos of your retinas to document the current appearance (they are used for comparing changes over the years, allows them to detect very subtle changes that might have been missed otherwise) or may perform an OCT – a light scan through the retinal tissue that can help detect early changes or find subtle signs of transition to the wet form of the disease.     

What can I do to lower my risks of developing macular degeneration?

Dry macular degeneration currently has no definitive cure; it is best treated by reducing risk factors, supplementing your diet with retinal supporting nutrients, and monitoring your eyes closely to detect a change to the wet form (if it happens) as soon as possible. If vision loss occurs and begins to affect your daily life, we can work with you on obtaining resources that help you maximize the vision you still have so you can maintain independence and a good quality of life. Reduced vision can be scary, especially when you’ve always seen well, but there are many adaptive ways to keep you doing the things you love.

Stop smoking: Quitting smoking is a huge factor in lessening your chances of the disease worsening. 

Protect yourself from UV: Using quality sun protection every time your outdoors is equally important. Hats and visors are recommended, and sunglasses are critical (wrap-around glasses with polarized lenses are best for reducing UV exposure). Obtaining and maintaining good cardiovascular health through diet and exercise is strongly encouraged. 

Exercise: moderate to high physical activity: Good blood flow, especially to all the capillaries, helps keep all your organs healthy, including your eyes. There doesn’t seem to be a protective benefit to light physical activity once you have mild AMD, but high levels of physical activity have been shown to be protective and lower your risk of AMD getting worse. Since blood delivers nutrients to cells, and exercise improve blood vessel function, there is likely a benefit of regular light to moderate physical activity for those with early drusen or strong family history of macular degeneration. This topic is not easily studied, but with all things being equal, being more active is better than being sedentary.

Diet changes and supplementation: Carotenoids are pigment molecules found in nature that create the reds, oranges, and yellows found in fresh fruits and vegetables.  These substances act as antioxidants in the human body, helping to protect the tissues in our body from damage over time.  Three carotenoids are prevalent in the retinal tissue in our eyes: lutein, zeaxanthin, and meso-zeaxanthin.  They play a critical role in keeping our photoreceptors functioning – thereby preventing the formation of macular degeneration!  It doesn’t matter how well our blood vessels work, if we don’t have the proper micronutrients to support the tissue, they can’t perform correctly.

Our bodies do not create these molecules, so we must get them from our diet.  Fresh produce like red and yellow peppers, dark leafy greens like kale and spinach, and squash provide these. Adding more of them to your diet can help to reduce your risk of developing (or progressing) macular degeneration.  Sometimes, supplementation (in pill form) is recommended.  The AREDs and AREDs2 studies were landmark research that showed that a specific combination of vitamins and minerals (including carotenoids) can reduce the risk of someone with moderate macular degeneration converting to the more severe (atrophy or wet) stage of the disease. As a result of these studies, there are now specific “eye vitamins” designed to protect the retina against AMD.  

Monitoring (at home and in our office): Finally, we may recommend that you monitor your vision carefully at home each day.  If your macular degeneration progresses to the wet stage, it often results in a change in vision that can be detected using tests at home.  The sooner it can be detected and treated (see the next section), the more likely you are to retain functional vision and prevent vision loss. 

Historically, a home test called the Amsler Grid was the gold standard, and is still often used today.  This is essentially a piece of high-contrast graph paper (dark black grid on bright white paper); by focusing on a specific point on the paper, people with early macular degeneration may notice some areas of the lines appear to be missing, or some lines may look wavy instead of straight.  Changes in how the lines appear over time can indicate a possible shift to the wet stage of the disease. 

More recently, electronic monitoring systems have been developed.  ForeSee Home is an AI-assisted home-monitoring device that uses a small screen, and you control the device with a small computer mouse.  It guides you through a short vision test, and will automatically contact your doctor if it detects a change in your vision compared with your previous tests.

In-office monitoring is especially important. After your exam, we will recommend you come back at a specific interval so that we may continue to look for subtle changes in your retinal tissue. The more damage/drusen, the more frequent your doctor will

How the wet form is treated:

Unlike dry AMD, the wet stage has proven treatments.  These treatments often involve applying a category of drug called Anti-VEGF agents inside the eyes.  A few of the common medications in this class are Avastin, Lucentis, and Eyelea.  These differ primarily in the frequency with which they have to be given to be effective. 

These medications are administered into the eye by injection at an ophthalmologist’s office (usually a retinal specialist).  If we detect a change suggesting your macular degeneration may have shifted to the wet form, we will quickly get you an appointment with an ophthalmologist’s office so that there is no delay in treatment.  The sooner wet AMD is detected and treated, the less chance there is of vision loss occurring, especially severe vision loss.

We’re here to help!

Macular degeneration can be scary and cause life altering changes to your vision. Early detection is key to slowing progression and functioning to your fullest potential. If you think you might be at risk of developing AMD, we encourage you to make an appointment. Knowing where you are right now, helps you to understand what is happening, and allows you to adapt to what might happen next. We want to be there to help you understand where you are no matter your current stage.