Understanding Macular Degeneration
Age-related Macular Degeneration (AMD) is one of the leading causes of central vision loss in patients over the age of 50. It affects the macula, the central part of the retina, which helps you see fine details and do everyday things like reading, driving, or recognizing other people.
There are two main types of age-related macular degeneration; the dry form and the wet form and knowing the distinction between the two is important for early detection and treatment. Learning about the differences between "dry" and "wet" AMD will help patients recognize early warning signs and receive timely care.
What is Dry Macular Degeneration?
Dry macular degeneration (also called non-neovascular AMD) is the most common cause of AMD, accounting for nearly 80-90% of cases. It develops slowly and gradually over time and is characterized by a thinning of the macula, and progressive breakdown of light-sensitive retinal cells. This can lead to blurry or distorted central vision and difficulty focusing on detail.
In dry AMD, small yellow deposits called drusen accumulate under the retina. As drusen increases in size, they affect the ability of the retina to process light accurately and can lead to distortion of vision or blind spots in the central vision.
Key signs and symptoms of dry macular degeneration include:
- Blurry or hazy central vision
- Difficulty reading or recognizing faces
- Colors appearing faded or less vibrant
- The need for brighter light when reading
- Straight lines appearing slightly distorted
While dry macular degeneration typically progresses slowly, it can advance into a more severe form known as geographic atrophy, where retinal cells die off completely, leading to permanent vision loss.
What Is Wet Macular Degeneration?
Wet macular degeneration (also known as neovascular AMD) is less common but more aggressive. It occurs when abnormal blood vessels grow beneath the retina and leak fluid or blood into the macula. This causes rapid damage to the retinal tissue and can lead to sudden vision loss if not treated promptly.
What are wet AMD symptoms?
- Sudden onset of blurry or distorted central vision
- Straight lines appearing wavy or bent
- Dark or blank spots in the center of vision
- Rapid worsening of vision quality
Unlike dry macular degeneration, which progresses slowly, wet macular degeneration can develop suddenly and severely impact vision in a matter of weeks or months. Early detection and treatment are essential to prevent permanent damage.
AMD Wet vs. Dry: The Key Differences
To better understand AMD wet vs. dry, here’s a comparison of how these two forms differ in cause, symptoms, and treatment:
| Feature | Dry Macular Degeneration | Wet Macular Degeneration |
|---|---|---|
| Prevalence | About 80-90% of AMD cases | About 10-15% of AMD cases |
| Onset | Slow and gradual | Rapid and often sudden |
| Cause | Thinning of macula and buildup of drusen | Growth of abnormal blood vessels under retina |
| Symptoms | Early vision distortion, faded colors, gradual blurriness | Wavy lines, dark spots, rapid central vision loss |
| Treatment | Lifestyle management, supplements (AREDS2), monitoring, anti-complement injections | Anti-VEGF injections, laser treatment, surgery |
| Prognosis | Often stable over years but can lead to late-stage vision loss | Can lead to severe vision loss without treatment |
Knowing which is worse; wet or dry age-related macular degeneration depends on severity and timing of diagnosis. While dry AMD progresses slowly, wet AMD poses a more immediate threat to central vision and requires urgent medical care.
Causes and Risk Factors for AMD
The underlying causes and risk factors for both dry and wet macular degeneration are the same:
- Aging (usually in those over 50)
- Family history of AMD
- Smoking and poor diet
- History of high blood pressure or cardiovascular disease
- Excessive exposure to sun
- Obesity or inactivity
Being aware of and managing these risk factors can lower the risk of progressing from early AMD stages to advanced stages.
How is Macular Degeneration diagnosed?
An eye doctor may help identify early AMD stages with a thorough retinal exam. Diagnostic tests may include:
- Dilated Eye Exam: Allows the doctor to see evidence of drusen deposits or retinal thinning
- Optical Coherence Tomography (OCT): Creates cross-sectional images of the retina to show signs of damage or fluid.
- Fluorescein Angiography: A test that injects a special dye to help see leaking or other signs of abnormal blood vessels, particularly leaking, in wet AMD.
Routine visits are very important for all patients, even those with no experience of symptoms, because early stages of AMD can exist without any symptoms.
Treatment and Management Options
For dry macular degeneration, treatment focuses on slowing progression and maintaining quality of vision. Evidence-based strategies include:
- Nutritional supplements (AREDS2 formula) to protect retinal cells
- Lifestyle modifications, including quitting smoking and maintaining a balanced diet
- Regular eye exams for ongoing monitoring
Wet macular degeneration requires more targeted therapies:
- Anti-VEGF Injections: Medications like Eylea, Lucentis, or Avastin reduce abnormal vessel growth and prevent leakage.
- Laser Photocoagulation: Seals leaky vessels to limit further retinal damage.
Prompt treatment for wet macular degeneration can help preserve central vision and prevent severe, permanent loss.
Living with Macular Degeneration
Although AMD is not curable, early treatment and ongoing management can help you stay independent and not lose visual function. Using magnifiers, having appropriate light, and eating a vision-friendly diet can all help your daily life.
You will also want to keep up with all the follow-ups recommended by your retina specialist. No matter if you have wet macular degeneration or dry macular degeneration, staying engaged and active in your care will make the biggest difference in the long run.
When to see a retina specialist
As soon as you experience any wavy lines, a sudden change in vision appreciation, or difficulty with focus, you should schedule an eye exam. Early optical examinations will help determine if your doctor thinks you have wet or dry AMD.
Dr. Paul Hahn, MD, PhD, FASRS, provides advanced care for those with macular degeneration and other retinal diseases. He utilizes the best diagnostic technology along with treatment options to preserve and protect your vision.