Dr. Katia Taba, Board-Certified Ophthalmologist and Retinal Specialist
What exactly is Macular degeneration? The macula is the central area of the retina that provides the most intricate details of sight, the ability to recognize faces, read small print, and drive. It is an oval area that receives light filtered through the cornea and lens, and it provides visual communication to the brain. When there is damage to the retina due to specific issues, degeneration can occur, and it is a serious disorder that should never be overlooked. In adults over the age of 50, age-related macular degeneration (AMD) is the leading cause of blindness. It is estimated that more than 10 million Americans have some degree of AMD, and unfortunately, although there is still no cure for the disease it might be preventable to some degree and comprehensive treatment for some forms of the disease are available for the past 15 years. Early diagnosis and treatment are optimal.
Dr. Taba of Personalized Retina Care of Naples wants to alert individuals about the signs and seriousness of this disorder. Recently the AAO (American Academy of Ophthalmology) published an article detailing the condition. A portion of that publication is below.
Age-related macular degeneration is a problem with your retina. It happens when a part of the retina called the macula is damaged. With AMD you lose your central vision. There are several forms or macular degeneration and the most common one is the age-related macular degeneration. You cannot see fine details, whether you are looking at something close or far. But your peripheral (side) vision will still be normal. For instance, imagine you are looking at a clock with hands. With AMD, you might see the clock’s numbers but not the hands.
Two types of AMD
Dry AMD
This form is quite common. About 80% (8 out of 10) of people who have AMD have the dry form. Dry AMD is when parts of the macula get thinner with age and tiny clumps of protein called drusen grow. You slowly lose central vision.
Wet AMD
This form is less common but much more serious. Wet AMD is when new, abnormal blood vessels grow under the retina. These vessels may leak blood or other fluids, causing scarring of the macula. You lose vision faster with wet AMD than with dry AMD.
Many people don’t realize they have AMD until their vision is very blurry. This is why it is important to have regular visits to an ophthalmologist. He or she can look for early signs of AMD before you have any vision problems.
Who Is at Risk for AMD?
You are more likely to develop AMD if you:
1. are over 50 years old
2. have a family history of AMD
3. smoke cigarettes
4. have hypertension (high blood pressure)
5. are overweight
6. eat a diet high in saturated fat (found in foods like meat, butter, and cheese)
*Having heart disease is another risk factor for AMD, as is having high cholesterol levels. Caucasians (white people) also have an elevated risk of getting AMD
In a Similar Publication, Genetics and Age-Related Macular Degeneration, describes how genetics plays a role in AMD.
Many Genes Influence AMD Risk, But Two Stand Out
Large genome-wide association studies have identified over 30 genes associated with the risk of developing AMD. These kinds of studies look for genes that are more common in people with certain conditions. If a lot of people have a particular variation of a gene and also have a particular condition—while other people without the variation don’t have the condition—that gene is said to be associated with the condition. Variants in all 30-plus of these genes contribute different levels of risk of developing AMD.
Variations in two genes have been more closely connected to both developing AMD and whether it progresses to the advanced stages of the disease. These are:
– the complement cascade (group of genes) on chromosome 1; and
– the ARMS2/HTRA genes on chromosome 10.
The presence of these genetic variants doesn’t mean that someone will definitely develop AMD. These variants mean that one may have a higher risk of AMD or developing advanced disease in the future.
The complement cascade is an essential part of the body’s immune system. It controls a series of proteins that protect against invading pathogens like bacteria and viruses. Complement can sometimes incorrectly target the body’s healthy cells, including cells in the retina.
Some researchers believe that inflammation and immune mechanisms are part of what causes AMD. The connection between complement gene variants and AMD supports this theory. There are several variants of the complement genes, and they create different levels of AMD risk.
While scientists are intensively researching ARMS2/HTRA1, the role of these genes in AMD is not yet understood. It appears there is a strong connection, but we don’t yet know what these genes do.
Other genes associated with increased AMD risk are involved in cholesterol and lipid (fat) metabolism, collagen production, DNA repair, protein binding, and cell signaling. Research on these genes and their role in disease onset and progression is still underway.
In addition, certain gene variants can have a protective effect against AMD, reducing an individual’s risk of developing the disease. These include variants in other parts of the complement and immune gene groups, and other genes that affect lipids.
Genetic Testing and The Future of AMD
Academy of Ophthalmology does not currently recommend genetic testing for AMD. Gene therapy is not available for prevention or management of the disease, so there is no benefit of identifying which genes are involved in any individual’s case of macular degeneration.
As future studies shed more light on AMD and individual genotypes—and if treatment tailored to individuals become available—genetic testing for AMD may become helpful. We may one day have targeted therapies for AMD based on the individual’s genes and lifestyle.
In the meantime, anyone with a family history of AMD should have their eyes examined as recommended by an ophthalmologist, get enough exercise, eat a well-balanced diet and quit smoking. If you have AMD, existing treatments, including vitamin supplements and medications, can be very effective.
Protecting & Preventing Vision
There are many things we can do to prevent loss of vision. Some of these include:
• Stop smoking
• Wear protective eyewear
• Wear sunglasses
• Control blood pressure
• Control blood sugar
• Exercise
• Reduce sugar and salt intake
• Eat a healthy diet that consists of omega-3 fatty
acids, lean protein (avoid red meat) and plenty of
fresh fruits and vegetables.
If you are experiencing any changes in your eye health, whether it is blurry vision, pain, impaired vision, or any other visual irregularities, it is imperative that you see an ophthalmologist right away. The earlier disease or disorders are detected, the better the outcome and treatment options are for you. You will find a friendly and warm environment at Personalized Retina Care of Naples. Please call (239) 325-3970 today to schedule your eye exam. Same-day appointments are still available.
Personalized Retina Care of Naples provides comprehensive diagnosis and treatment for retinal disorders. Dr. Taba also gives second opinions on retinal and general eye conditions. Dr. Taba is a Board-Certified Ophthalmologist and is Fellowship trained in surgical and medical retinal diseases.
There are ways to regain your independence and correct low vision. To find out more, or to schedule your appointment, please call (239) 325-3970 today.
1. K Boyd, What Is Macular Degeneration? American Academy of Ophthalmology, https://www.aao.org/eye-health/diseases/amd-macular-
degeneration
2. R. Mukamal, Genetics and Age-Related Macular Degeneration, American Academy of Ophthalmology, April 2019, https://www.aao.org/
eye-health/diseases/age-related-macular-degeneration-amd-genetics