Macular Degeneration is the leading cause of vision loss, affecting more than 10 million Americans – more than cataracts and glaucoma combined.
Macular Degeneration is caused by the deterioration of the central portion of the retina, the inside back layer of the eye that records the images we see and sends them via the optic nerve from the eye to the brain. The retina’s central portion, known as the macula, is responsible for focusing central vision in the eye, and it controls our ability to read, drive a car, recognize faces or colors, and see objects in fine detail. Stargardt disease is a form of macular degeneration found in young people, caused by a recessive gene.
Types of Macular Degeneration
There are two basic types of Macular Degeneration: “Wet” and “Dry.” Approximately 85% to 90% of the cases of Macular Degeneration are the “dry” (atrophic) type, while 10-15% are the “wet” (exudative) type.
Wet Macular Degeneration
In the “wet” type of macular degeneration, abnormal blood vessels (known as choroidal neovascularization or CNV) grow under the retina and macula. These new blood vessels may then bleed and leak fluid, causing the macula to bulge or lift up from its normally flat position, thus distorting or destroying central vision. Under these circumstances, vision loss may be rapid and severe.
With the “wet” type, patients may see a dark spot (or spots) in the center of their vision due to blood or fluid under the macula. Straight lines may look wavy because the macula is no longer smooth. Side or “peripheral” vision is rarely affected. However, some patients do not notice any such changes, despite the onset of neovascularization (1). Therefore, periodic eye examinations are still very important for patients at high risk.
Dry Macular Degeneration
“Dry” age-related macular degeneration does not involve any leakage of blood or serum. Loss of vision may still occur. Patients with this “dry” form may have good central vision (20/40 or better) but substantial functional limitations, including fluctuating vision, difficulty reading because of their limited area of central vision, limited vision at night or under conditions of reduced.
Age-Related Macular Degeneration (AMD)
Age-Related Macular Degeneration (AMD) is one of the leading causes of vision loss for people over the age of 50. The early stage of dry age-related macular degeneration is associated with minimal visual impairment and is characterized by large drusen and pigmentary abnormalities in the macula. Drusen are accumulations of acellular, amorphous debris subjacent to the basement membrane of the retinal pigment epithelium. Nearly all people over the age of 50 years have at least one small druse in one or both eyes. Only eyes with large drusen are at risk for late age-related macular degeneration.
In AMD patients, vision loss occurs as the macula deteriorates over time. The macula is the part of the retina responsible for sharp, central vision, AMD can make it difficult or impossible to do daily tasks like reading, writing, and driving.
Who Is At Risk?
Macular degeneration can happen earlier in life, but age is easily the biggest risk factor. A few others include race and genetics. Unfortunately, none of these factors are things we can control, but we can control whether or not we smoke, as smoking is yet another risk factor for AMD.
Symptoms Of AMD
AMD often goes undetected for a long time because it is painless and the negative effects on vision take a while to manifest. Over time, however, blurry patches or dark spots will begin to appear in the central vision. Objects may also appear less bright than they used to, or they may seem warped.
Stages of Macular Degeneration
There are three stages of Age-related Macular Degeneration (AMD).
- Early AMD – Most people do not experience vision loss in the early stage of AMD, which is why regular eye exams are important, particularly if you have more than one risk factor (see below). Early AMD is diagnosed by the presence of medium-sized drusen (yellow deposits beneath the retina).
- Intermediate AMD – At this stage, there may be some vision loss, but there still may not be noticeable symptoms. A comprehensive eye exam with specific tests will look for larger drusen and/or pigment changes in the retina.
- Late AMD – At this stage, vision loss has become noticeable.
If you have already been diagnosed with Macular Degeneration, here are Ten Questions to Ask Your Doctor.
Causes of AMD
The specific factors that cause macular degeneration are not conclusively known, and research into this little understood disease is limited by insufficient funding. At this point, what is known about age-related Macular Degeneration is that the causes are complex, but include both heredity and environment. Scientists are working to understand what causes the cells of the macula to deteriorate, seeking a macular degeneration treatment breakthrough. They know the causes are not the same for Age-related Macular Degeneration as they are for Stargardt disease. Stargardt disease has a specific genetic cause in most cases, whereas AMD involves both genetic and environmental factors.
Dr. Carl Kupfer, the former Director of the National Eye Institute, National Institutes of Health, has stated that Macular Degeneration will soon take on aspects of an epidemic as the Baby Boomers’ age: “As the “baby boom” generation ages, and in the absence of further prevention and treatment advances, the prevalence of AMD is estimated to reach epidemic proportions of 6.3 million Americans by the year 2030.”
Risk Factors
The biggest risk factor for Macular Degeneration is age. Your risk increases as you age, and the disease is most likely to occur in those 55 and older.
Other risk factors include:
- Genetics – People with a family history of AMD are at a higher risk.
- Race – Caucasians are more likely to develop the disease than African-Americans or Hispanics/Latinos.
- Smoking – Smoking doubles the risk of AMD.
Helping Your Eyes Stay Healthy
There is currently no cure for AMD, but there is still a lot we can do to reduce our risk of developing it and slow its progress after diagnosis. The most important thing is to build and maintain healthy habits.
Regular exercise and healthy eating promote whole-body wellness, and that includes eye health. Make sure to include plenty of carrots, fish, leafy greens, and eggs. Wearing UV-blocking sunglasses and avoiding smoking will also help protect your eyes.
The Role Of The Optometrist
In addition to those good habits, scheduling regular eye exams is critical. The earlier your optometrist can catch AMD, the more we can do to slow it down. If you’re worried that you could be at risk of AMD and especially if you’ve been experiencing any symptoms, call or stop by to schedule an appointment right away!
Your clear vision is our top priority! To schedule an appointment with us, please text or call 407-292-9812.
Top image used under CC0 Public Domain license. Image cropped and modified from original.
The content on this blog is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of qualified health providers with questions you may have regarding medical conditions.
