May 10, 2024—When we are young, we take our macula for granted. At the center of our retina—the deepest layer of the eye, packed with photoreceptors that give our world its color—the macula acts like a high-resolution camera. When light hits our eyes, the macula reshapes our world into brilliant colors with astonishingly high visual clarity.
But as you age, your vision becomes dull. What was once noticeable becomes blurry, like condensation on a window pane. After a while, coal-black smudges or cloudy round areas begin to affect your central vision.
If left untreated, this effective blind spot can expand over time. What’s left is a “macular hole” in the center of the retina.
This series of unfortunate events marked the age-related macular degenerationa dangerous retinal disease that affects approximately 20 million people in the United States and nearly 200 million people worldwide.
And it’s not getting any better. It is estimated that the disease could affect nearly 300 million people worldwide by 2040. Our ability to treat or prevent it is very limited. Read on to learn more.
First, what causes age-related macular degeneration?
There are many causes of AMD, and whether it affects you depends primarily on your age and genetics, says Marco Alejandro Gonzalez, MD, an ophthalmologist and vitreoretinal specialist in Delray Beach, Florida.
Because of our different genetic makeup, the photoreceptor cells in some humans’ macula “basically start to shut down,” he said.
More than 30 genes are involved in the development of AMD, and you are three times more likely to develop the disease if you have a first-degree relative (parent, sibling, child) with the disease.
Gonzalez explained that the number of cases is expected to increase to 300 million by 2040, mainly due to improvements in diagnostic tools and the fact that the world’s population is aging and living longer. (Often, an optometrist can Detecting signs of AMD During a routine eye exam.
Eye experts are still trying to prevent AMD’s most harmful symptom, the cause of cloudy, milky or even coal-colored circles in central vision: geographic atrophy.
Geographic atrophy can occur in two forms of elderly AMD: “dry” AMD and “wet” AMD.
Nearly all cases of AMD Start with something dryaffecting 80% to 90% of AMD patients.
Dr. Tiarnán Keenan, an expert in retinal diseases, provides a vivid picture of geographic atrophy for patients with dry AMD.
“Over time, the round patches of GA can grow like a bushfire, taking away more and more vision, often to the point of legal blindness,” he said.
Keenan, a researcher in the National Eye Institute’s Division of Epidemiology and Clinical Applications, recently led a study study The study tested the efficacy of the antibiotic minocycline in slowing the spread of geographic atrophy in dry AMD. The rationale for the study is that the body’s immune system may play a role in the development of the disease.
When your body’s immune system is overactive, microglia (central nervous system immune cells) enter the subretinal space and may engulf the macula and its sensitive photoreceptors.
Although minocycline has been shown to reduce inflammation and microglial activity in the eyes of patients with diabetic retinopathy, in Keenan’s study it did not slow the progression of geographic atrophy or vision loss in patients with dry AMD.
When asked whether microglial activity had little to do with the atrophy expansion, Keenan said it was something to consider: “Maybe microglia are just bystanders cleaning up debris…so inhibiting them is unlikely to slow progression.”
In future drug trials, “maybe minocycline or another approach that targets microglia could help, but it would need to be combined with some other therapies and would be ineffective on its own,” he said. .
Both sides of the same disease
For dry AMD, Gonzalez compared macular degeneration to the loss of pixels on the screen. “Some of those pixels will be burned out… and that’s how typical dry forms of vision loss occur.”
Wet AMD is a highly progressive disease. It can cause sudden loss of vision due to abnormal growth of blood vessels.
“If you don’t treat wet AMD soon, it’s game over,” Gonzalez warned. “Wet macular degeneration is a faster process of vision loss because these blood vessels wreak havoc.” These new blood vessels bleed, causing fluid to build up in the macula, which ultimately leads to scarring.
Gonzalez reveals why wet AMD occurs. “For some reason, the wet form is the body’s last ditch effort to try to ‘help’ the dying macula. … When these blood vessels begin to grow under the retina, they rapidly destroy the structure of the macula.
Hemostasis in wet AMD
Although wet AMD is rare, it is easier to treat than dry AMD.Signs and symptoms can be relieved through a variety of therapies Inject into eyes.
In short, Gonzalez says, these treatments for wet AMD “basically all do the same thing. They cause these new blood vessels to temporarily recede before they cause damage to the macula.
The injected medication clears these blood vessels and restores the structure of the macula. People can regain some vision this way, but it’s only a temporary adjustment and the injections must be given once a month.
“Cell degeneration is still the main problem. You don’t stop that. But the degeneration itself is much slower than the actual vision loss associated with these blood vessels.
The struggle to develop new treatments
“No one can prevent the occurrence of geographic shrinkage in any form of AMD,” Keenan said. “So, that’s the main thing to try in this area.”
In December 2023, the FDA approved two new drugs: Syfovre and Izervay, both of which are only slow Geographic shrinkage. Regardless, degradation still occurs.
Keenan explained that the two new drugs are “complement inhibitors … that are injected into the eye about once a month.”
“Complement” refers to the body’s complement pathway, A trigger that activates a series of proteins to enhance the immune response.
Clinical trial shows Syfovre slows geographic shrinkage by up to 22% growth in 2 yearsIzervay as high as 14% in one year.
While these drugs are new weapons in the fight against this troublesome disease, they are not without complications.
“Anytime you inject an eye, there’s always a risk of infection because you’re introducing something from the outside. So that’s the biggest risk,” Gonzalez explained.
Infection is uncommon but can be devastating as you may lose your eye completely. Shooting also has the potential to produce destructive reactions.
“You have to pick your patients,” Gonzalez said. “Not everyone is a candidate for the new injections…and patients’ vision never gets better. …It’s a harder sell than wet AMD.”
Common protective measures
Both Keenan and Gonzalez are confident that vitamin therapy can reduce the risk of AMD.
As some background on how vitamins were discovered as a preventive measure, Gonzalez said, “In the early and late ’90s, there was a series of studies called the Age-Related Eye Disease Studies.” These are now called AREDS 1 and AREDS 2.
Researchers have shown that a certain mixture of vitamins can slow down degeneration. The biggest of these is the antioxidant combo: 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 in the next 2 to 5 years. “[The combo] It appears to be complementary and additive…the combined treatment efficacy is 55% to 60%, the safety record is excellent, and the cost is very low,” Keenan said.
Gonzalez recommends AREDS 2 vitamin formula to every patient. “It’s an easy thing to do and the downsides are minimal.”
Unfortunately, if your genes make you more likely to develop the disease, dietary changes or vitamin use may not have any effect.
Is it scary? Maybe. But all is not lost in this fight.
Staying vigilant about AMD and what to do next after being diagnosed
Gonzalez insists on educating patients before time runs out to treat AMD. Recognition is key. “The most common reason these people come to me ‘too late’ is that they didn’t realize there was a problem.”
He explains a typical scenario: “Let’s say you have macular degeneration in both eyes at various stages. One of your eyes starts to develop wet macular degeneration…so the better eye takes over and you may not notice it’s there. question.
Even when patients are diagnosed with AMD, they typically see a specialist only twice a year. Gonzalez often tells his patients to cover one eye to ensure vision in both eyes is intact. “You’ll be able to detect subtle differences in each eye,” he said.
This type of self-care and vigilance can be the difference between successfully living with and treating this disease for the rest of your life, and trying to get help when it’s too late.
For wet AMD, as mentioned earlier, a round of injections is basically what everyone does. Without quick, invasive treatment, it can quickly lead to an irreversible situation.
