May 10, 2024 – When we are young, we take our macula for granted. The macula, located at the center of our retina (the deepest layer of the eye that is packed with photoreceptors and gives color to our world), is like a high-definition camera. When light hits our eyes, the macula retina colorfully reprojects our world with astonishingly high visual clarity.
However, as we age, our eyesight deteriorates. What used to be clearly visible now becomes cloudy, like condensation on a windowpane. After a while, pitch-black smudges or cloudy circular areas begin to affect your central vision.
This effective blind spot grows over time if left untreated. What remains is the macular hole in the center of the retina.
This unfortunate series of events shows that society is at an advanced stage. age-related macular degenerationa dangerous retinal disease that affects approximately 20 million people in the United States and approximately 200 million people worldwide.
And it's not getting better. It is estimated that by 2040, nearly 300 million people worldwide could be affected by this disease. Our ability to treat or prevent it is very limited. Read on to find out what you need to know.
First, what is the cause of age-related macular degeneration?
Dr. Marco Alejandro Gonzalez, an ophthalmologist and vitreoretinal specialist in Delray Beach, Fla., says there are many different causes of AMD, and whether a person is affected by AMD is largely determined by age and genetics.
Because our genetic makeup varies, he said, in some people the photoreceptor cells in the macula „basically start to stop functioning.“
More than 30 genes are involved in the development of AMD, and if you have a first-degree relative such as a parent, sibling, or child with the disease, you are three times more likely to have it too. Become.
Gonzalez explained that the number of infections is expected to rise to 300 million by 2040, mainly due to improved diagnostic tools and the world's aging and longer lifespans. (Usually, optometrists Detect signs of AMD during a routine eye exam. )
Eye experts are still struggling to stop geographic atrophy, which is responsible for AMD's most harmful sign: cloudy, milky, or even coal-colored circles in central vision.
Geographic atrophy can occur in one of two forms of age-related AMD: “dry” AMD and “wet” AMD.
Almost all cases of AMD Start with dry typeaffecting 80% to 90% of AMD patients.
Retinal disease expert Tiarnan Keenan, MD, provided a clear picture of geographic atrophy in patients with dry AMD.
„Over time, the circular patches of GA spread like bushfires and become increasingly blinding, often to the point of legal blindness,“ he says.
Keenan, a researcher in the National Eye Institute's Division of Epidemiology and Clinical Applications, recently study This study tested the effectiveness of the antibiotic minocycline in slowing the spread of geographic atrophy in dry AMD. This study was conducted on the basis that the body's immune system may be involved in the development of the disease.
When the body's immune system becomes overactive, microglial cells (central nervous system immune cells) can enter the subretinal space and attack the macula and its sensitive photoreceptors.
Minocycline has been shown to reduce inflammation and microglial activity in eyes with diabetic retinopathy, but Keenan's study did not slow the spread of geographic atrophy or vision loss in patients with dry AMD.
Asked whether microglial activity may have little to do with the spread of atrophy, Keenan said that's something to consider, adding: „Perhaps microglia are just there as bystanders cleaning up the debris. „Therefore, inhibiting microglia is unlikely to slow progression.“
In future drug trials, he said, „minocycline or another approach that targets microglia may be helpful, but it will need to be combined with other treatments and will not be effective alone.“ .
two sides of the same disease
For dry AMD, Gonzalez likens macular degeneration to the loss of pixels on a screen. „Some of these pixels burn out…and that's how you classically lose your vision in dry conditions.“
Wet AMD is a more progressive disease. Abnormal growth of blood vessels causes sudden loss of vision.
„If we don't treat wet AMD right away, it's game over,“ Gonzalez warned. „Wet macular degeneration causes vision loss to progress more quickly because these blood vessels wreak havoc.“ These new blood vessels bleed and fluid builds up within the macula, eventually leading to scarring. Masu.
Gonzalez revealed why wet AMD develops. „For some reason, the moist form is the body's last effort to 'help' the dying macula. …When these blood vessels begin to grow under the retina, they quickly destroy the structure of the macula. ”
Stopping bleeding in wet AMD
Wet AMD is rare but more treatable than dry AMD.Signs and symptoms can be alleviated with various treatments Injected into the eye.
Simply put, these treatments to treat wet AMD „all basically do the same thing: These new blood vessels temporarily regress before they cause damage to the macula.“
The injected drug removes those blood vessels and repairs the structure of the macula. Although this method can restore some vision, it is only a temporary adjustment and injections must be given about once a month.
„Cellular degeneration is still the main problem. It's not stopping it. But the degeneration itself is much slower than the actual vision loss associated with these blood vessels.“
Struggles in developing new treatments
According to Keenan, „no one has been able to stop geographic atrophy from occurring“ in either form of AMD. „So that's the main work in the field with testing.“
In December 2023, the FDA approved two new drugs: Syfovre and Izervay. slow Geographical atrophy. Nevertheless, degeneration still occurs.
Keenan explained how these two new drugs are „complement inhibitors…that are given by injection into the eye about once a month.“
„Complement“ refers to the body's complement. complement pathway, Triggers that activate a cascade of proteins that enhance the immune response.
In clinical trials, Syfovre was shown to slow down the rate of geographic atrophy by up to 100%. 22% in 2 yearsIzervay up to 14% in one year.
These drugs are a new weapon against this nasty disease, but they are not without complications.
„When you inject into the eye, you're introducing something from outside, so there's always a risk of infection, so that's the biggest risk,“ Gonzalez explained.
Although the infection is rare, it can have devastating effects, as it can result in complete loss of the eye. There is also the possibility of an adverse reaction to the shot.
„Patients have to make their own choices,“ Gonzalez says. „Not everyone will be a candidate for the new injections…and the patient's vision will never get better….Wet he is a harder sell than the one for AMD.“
General protection measures
Keenan and Gonzalez are pretty confident that vitamin therapy can reduce the risk of AMD.
Giving a little background on how vitamins were found to work as a kind of preventive measure, Gonzalez says, „In the early to late 90s, there was a series of studies called the Age-Related Eye Disease Study. ” he said. These are now called AREDS 1 and AREDS 2.
Researchers have proven that a cocktail of certain vitamins slows degeneration. Most important is the combination of antioxidants such as vitamins C and E, lutein and zeaxanthin, all of which are included in the AREDS 2 formula.
People who take these vitamins are less likely to lose their vision over the next two to five years. „[The combination]appears to be complementary and additive…combined treatment efficacy is 55% to 60%, there is an excellent safety record, and it is very low cost,“ Keenan said.
Gonzalez recommends the AREDS 2 formula of vitamins for all of his patients. „It's very easy and the downside is minimal.“
Unfortunately, if your genes predispose you to this condition, changing your diet or vitamin use may not help.
terrible? probably. However, not all is lost in this battle.
What to do next if you are diagnosed with AMD
Gonzalez is passionate about educating patients before time runs out to treat AMD. He is important to recognize. „The most common reason many of these people contact me 'too late' is that they don't realize there's a problem.“
He described a typical scenario: “Let’s say you have macular degeneration in both eyes at different stages. One of your eyes starts to develop wet macular degeneration…so your better eye takes priority and you may not realize there is a problem. there is.“
Even after a patient is diagnosed with AMD, they typically see a specialist only twice a year. Gonzalez often asks patients to cover one eye to make sure vision in both eyes is intact. Each eye „will be able to discern subtle differences,“ he said.
This kind of self-care and vigilance can be the difference between successfully living with and treating your illness for the rest of your life, or simply trying to seek help when it's too late.
For wet AMD, as mentioned above, injections are basically something everyone does. Without prompt invasive treatment, the point of no return is quickly approached.